CA1265273A - Integrated calling directory - Google Patents

Abstract

Integrated Calling Directory Abstract The integrated calling directory of the present invention eliminates the disadvantages of prior call directory arrangements by providing a software system which runs on a personal computer to automate the call directory and call origination function. The personal computer is interposed between an individual's telephone station set and the business communication system port circuit associated with the individual's telephone station set. The calling directory software both contains the individual's personal directory entries and has access to directory entries in the centralized business communication system data base which resides on an adjunct processor. These directory entries all contain called party identification data which includes information such as an individual's name, room number, electronic mail address, telephone number, type of terminal equipment associated with the called party, job title, etc.

Description

~ 1 --Integrated Calling Directory 1. Field of the Invention This lnvention relates to call directories and, in particular, to an integrated calling directory that resides on a user's personal computer The personal computer is connected to a business com~unication system. The integrated calling directory has access to both directory information stored in the memory of the personal computer and centralized directory entries which are stored on the business communication system.
Back~round of_the Invention Existing call directories are data bases generally found on an adjunct processor associated with the business communication system, which data base contains entries identifying an individual's name, address, organization, telephone nurnber and other pertinent information. This centralized data base is accessible in the dial-up mode by subscribers who are served by the business communication system a~ by directory assistance operators who generally have their terminals hard-wired to an adjunct processor which contains the data base. An individual who wishes to obtain directory information from the data base must use one of these terminal access points to query the data base.
Another call directory arrangement is found on personal computers where an individual can create their own personal call directory data base on their personal computer. This data base contains entries similar to those contained in the centralized call directory data base. An additional capability is provided by the pexsonal computer wherein the personal computer can ~J,3 output an identified individual's telephone number as dial pulse or louch-rone signals to originate a telephone call throu~h the business communication system to the identified individual. In similar fashion, files resident on the personal computer can be electronically transferred to an identified destination by the personal computer, under control of the subscriber, by the subscriber attaching an electronic mail address to the file and outputting same over the telephone lines through the business communication system to the identified destination.
A significant disadvantage of these call directory arrangements is that the subscriber must perform a number of operations to transmit information to an identiEied individual or destination. The subscriber must access the call directory, input the identified individual's name, receive the entry from the call directory identifying the called party's room number, telephone number or electronic mail address.
The subscriber must then take the received information and input it to their terminal or personal computer and indicate to the personal computer that this inEormation must be us~d to originate ~ call connection or data transfer to the identi~ied called party. This sequence of operations is time consuming and error prone.
Summa~y of the Invention _____ The integrated calling directory of the present invention eliminates the disadvantages of prior call directory arrangements by providing a software system which runs on a personal computer to automate the call directory and call origination function. The personal computer is interposed between an indlvidual's telephone station set and the business communication system port circuit associated with the individual's telephone statlon set. The calling directory software both contains the individual's personal directory entries and has access to directory entries in the centralize~ business comm~nication system data base which resides on an adjunct processor. These directory entries all contain called party identification data which includes information such as an individual's name, room number, electronic mail address, telephone number, type of terminal equipment associated with the called party, job title, etcO
The integrated calling directory software responds to a message created by the subscriber on the personal computer by automatically analyziny the format of the message so created and certain message-dependent characteristics of the identified destination, such as ; type of terminal equipment. The calling directory software automatically selects the message transmission medium, accesses the appropriate directory entry to create the message header appropriate for the media selected by the calling directory software, then transmits the completed message to the designated destination using the medium selected. The calling directory software can obtain the calling directory information either from an individualized data base residing on the personal computer or the centralized data base resident on the adjunct processor associated with the business communication system. The calling ~5 directory software automatically accesses the appropriate one of these two data bases to obtain the identification of the called party's destination description.
The calling directory software of the present invention automates the entire message transmission function and eliminates the need for the subscriber to sequentially access a call directory then input the selected destination address into the personal computer and perform a call origination function. The integrated calling directory software combines all of these functions into a simple single feature activation by the subscribe~. This combination eliminates a potential for ~6~

improper or incorrect data entry and the time consuming sequential operations of the prior art call directory arrangements.
In accordance with one aspect of the invention there is provided in a business communication system which serves a plurality of terminal devices, each of which is connected to the business communication system by an associated port circuit, said business communication system including at least one centralized calling directory file for storing a list of called parties and their telephone numhers, calling directory apparatus associated with one of said terminal devices for automatically originating a call through said business communication system to a called party designated by a user at said one terminal device comprising: processing means; means interposed between said one terminal device, its corresponding port circuit and also connected to said processing means for connecting s~id processing means to both said port circuit and said one terminal device; calling directory file means in said processing means for storing a list o~ called parties and their associated telephone numbers; means in said processing means responsive to said user entering the name of said called party into said one terminal device ~or sequentially scanning said calling directory file means and said centralized calling directory using said name of the called party to obtain the telephone number of said called party; means in said processing means for originating a communication connection to said called party via said connecting means in response to said scanning means locating the name of said called party; adjunct processing means connect to said business communication system via one of said port circuits for storing a centralized list of called parties and their associated telephone numbers;
means in said originating means responsive to said scanning means failing to locate an entry in said ~`:3~..

6.~ ~ 3 - ~a -calling directory file means corresponding to said nameof the called party ~or establishing a communication connection to said adjunct processing means via said connecting means; and means .in said originating means responsive to said communication connection for querying said adjunct processing means to obtain the telephone number associated with said name o~ the called party from said centralized list.
In accordance with another aspect of the invention there is provided in a business communication system which serves a plurality of terminal devices, each of which is connected to the business communication system by an associated port circuit, said business communication system including at least one centralized calling directory file for storing a list of called parties and their associated telephone numbers, at le,ast one of said terminal devices having calling directory apparatus interposed between said one terminal device and said business communication system a calling directory method for automatically originating a call through said business communication system to a called party desi.gnated by a user at said one terminal device comprising the steps of: sequentially scanning, in response to the entry o~ the name of said called party into said one terminal device, the calling directory file of said calliny directory apparatus and said centralized calling directory to obtain the telephone number associated with said name of said called party;
and originating a communication connection from said one terminal device to said called party us,ing said telephone number obtained from said calling directory file.
Brief Description of the Drawings FIG. 1 illustrates the subject business communication system and the various devices connected thereto in block diagram form;

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- 4b -FIG. 2 illustrates the interface apparatus of the subject invention in block diagram form;
FIG. 3 illustrates a detailed schematic diagram of the subject inter-face apparatus;
FIGS. 4 through 6 depict the details of the business communication system port circuit;
FIG. 7 illustrates the method of arranging FIGS. 4 through 6;
FIG. 8 depicts the details of the DCP
signaling protocol;
` FIG. 9 depicts the details of the HDLC message i frame; and FIG. 10 depicts the three different modes of connectivity between the device driver, communication management application and the DCP interface card;
FIG. 11 illustrates a typical call management display on the screen of the personal computer:
FIG. 1~ illustrates in flowchart form the operation of the call directory apparatus; and FIG. 13 illustrates a typical call log entry display on the screen of the personal computer.
_etailed Description The business communication system of this invention is illustrated in FIG. 1. This system includes a plurality of terminal equipment T11-T58 each of which is associated with a respective one of port circuits 111-158. This terminal equipment includes telephone station sets as well as digital terminal devices and computer facilities. A switching network 101, which comprises a time slot interchange t~3 circuit of the type illustrated in U. S. Patent No. 4,112,258, issued to H. G. Alles, September 5, 1978, is connected to a number of port clata/control interface circuits 171-175. Each port data/control interface circuit (eg. 171) shown in FIG. 1 serves eight port circuits tlll-118) and f~nctions to interface these port circuits wlth switching network 101 as well as system processor 100. Swi tching nets~lo rk 101 operates under control of system processor 100 and establishes 10 communication connections among the termi nal equipment by interconnecting the associated port circuits 111-158.
The termi nal equipment connected to port circuit 151 consists of the subject interface arrangement embodied in personal computer PC51 which is 15 equipped with a DCP i nterface card and a digi tal telephone station set T51. Personal computer PC51 is interposed between port circuit 151 and digital telephone station set T51 and serves to provide communication services to digi tal telephone station set 20 T51. This is accompl ished by the use oE DCP interface card 201 shown in block diagram form in FIG. 2.
DCP InterEace Card ~CP i nter:Eace card 2 01 i s plug ged .into one of the expansion sl ots of personal computer PC5 1, where 25 personal computer PC51 can be, or example, an AT&T
PC6300 computer. DCP i nterface carcl 201 consists of two in~;erface devices, telephone station set interface 202 and business communication system interface 206, which interconnect personal computer PC51 to digital telephone 30 station set T51 and port circuit 151 respectively.
Leads 203 and 205 connect telephone station set interface 202 and business communication system interface 206 respectively to bus communication controller 204.
DCP interface card 201 receives all transmissions from port circuit 151 in business communication system interface 206 via communication leads T~51. Bus communication controller 204 receives an interrupt signal from business communication system interface 206 via leads 205 and reads the transmissions from port circuit 151 stored in business communication system interface 206. Bus communication controller 204 responds to these transmissions by generating an interrupt signal on PC BUS 207 to personal computer PC51. Personal computer PC51 serves the interrupt by reading the transmission stored in bus communication controller 204 via PC B~S 207, and storing the transmission in memory 208. Personal computer PC51 contains communication managemeilt applica~ion 210 to process the received transmission from port circuit 151 Device drivers 211 interfaces communication management application 210 with DCP interface card 201. Device drivers 211 contains two basic components: interrupt service routine 212 and application interface process 213. The functions of device drivers 211 are: process interr~lpts from DCP interface card 201; buffer and transfer data between DCP interace card 201 and communication management applicatlon 210; provide a simple interface to communication management application 210 fo;r basic call setup and data transfer handle data call setup procedures with the business communication system as wi:ll be discussed below.
IE the processiny of the received transmission requires a change in the status of digital telephone station set T51, processor 209 transmits control signals to bus communication controller 204 via PC BUS 207.
These control signals are forwarded by bus communication controller 20~ to digital telephone station set T51 via leads 203 and telephone station set interEace 202.
Transmissions from digital telephane station set T51 to port circuit 151 are handled in similar fashion, with the above described process being rever~ed. The operation of DCP interface card 201 and : communication management application 210 is described in . .

further detail below in the description of FIG. 3. To provide an explanation of the DCP signaling protocol, the following description discusses a typical port circuit and the functions performed therein.
Terminal Equipment The standard digital terminal Tll generates an RS232 signal output which has a very limited transmission range. A digital terminal interface module (e.g.-DTll) is used to convert the ~S232 signals output by digital terminal Tll to alternate bipolar modulated code siynals which can be transmitted a significant distance over communication leads TRll to the port circuits 111 of the business communication system. The digital terminal interface module DTll is either an integral part of the digital terminal or connected between the existing digital terminal Tll and the associated communication leads TRll. This digital terminal interface module is disclosed in detail in U.S.
Patent No. ~,535,198 issued August 13, 1985, to G. N. Squicciarini.
; In addition to this signal conversion, digital terminal interface module DTll uses a particular message Erame format ~DCP) to efEect data transmission between port circuits such as 111 and their a-~sociated digital ~5 terminals BUCh as Tll. This DCP format consists of a framing bit and three fields: an S field that conveys control signaling data, and two I fields that convey information data (E'IG. 8). This is a well-known data transmission format as described in the article by N. Accarino et al entitled, "Frame-Mode Customer Access to Local Integrated Voice and Data Digital Network"
published in the Conference Report of the IEEE 1979 International Conference on Communications. In this DCP
data transmission format, one of the I fields can be used for the transmission of PCM-encoded voice information while the other one (or both I fields) can be used for the transmission of either bulk or interactive data.
Message Format The terminal equipment served by the business communication system may be various types of equipment and the terminal equipment illustrated in FIG. 1 has concurrent voice and data transmission capability. In this syste~, all the terminal equipment which receive voice transmissions from the user convert the received analog voice signals into a set of digital data segments, each comprising an eight bit PCM-encoded voice sample. The terminal equipment which generates digital transmissions (such as keyboards) receive and originate digital data messages which are generally of length greater than eight bits. A typical format (HDLC) of these data messayes is illustrated in FIG. 9, wherein each data message includes flag characters at the beginning and end of the data message; data, control and address fields; and a cyclic redundancy check field for error checlcing purposes.
Signaling Chann_ This business communication system is equipped with two signaling channels which reflect the basic DCP
message Erame ~ormat used by the port circuits. In particular, a control signaling channel (S channel) conveys control messages (S field bits) between system processor 100 and digital terminals Tll-T58. The S channel extends from each digital terminal (such as Tll) through associated digital terminal interface module (DTIM) DTll, communication leads T ~ 1, port circuit 111, leads Pll and thence through port data/control interface circuit 171 to system processor 100 via I/O BUS. The business communication system is also equipped with an information channel (I channel) which conveys information data (I field segments) such as the eight-bit PCM-encoded voice signals or bulk data (in eight-bit bytes) between switching network 101 and digital terminals Tll-T58.

The I channel extends from each digital terminal (such as 'rll) through associated digital terminal interface module (DTIM) D'rll, communication leads T ~ 1, port circuit 111, leads Pll and thence through port data/control interface circuit 171 to switching network 101 via leads PAl.
Thus, the digital terminal and its associated digital terminal interface module multiple~ the actual data transmissions (voice and data) with the control signals. This multiplexed signal is then transmitted over the communication leads to the associated port circuit where it is demultiplexed. The actual data transmission is switched in traditional fashion by switching network 101 to the designated destination and the control signals are forwarded to system processor 100. Again, these control signals are the standard on-hook/off-hook status, button operation, lamp lighting, and ringing signals common to all telephone switching systems. To effectively illustrate the structure and operation of the subject interface arrangement, the details of the existing port circuit and especially the S channel must first be explored.
I Channel Realiæation System processor 100, in the course of connecting a calling digital terminal (Tll) to a called`
digital terminal (T58~, assigns a time slot in switching network 101 for the interco~nection of digital terminals Tll and T58. Switching netwo.rk 101 controls the data (I channel) transmissions between digital terminals Tll-T58. In particular, switching network 101 transmits each eight bit data segment received from digital terminal T58 to port circuit 111 via port data/control interface circuit 175. Port circuit 111 transmits each data segment so received to digital 3~ terminal Tll via digital terminal interface module (DTIM) DTll and also receives a reply data segment from digital terminal Tll via DTIM DTll for transmission to 6~ s 5 ~ rX ~3 digit~l terminal T58. Port circuit 111 transmits the reply data segment received from DTIM DTll to switching network lOl via port data/control interface circuit 171.
Switching network ~01 stores the received data segment, and interchanges the data segments received from digital terminal Tll and digital terminal T5g during the time slot assigned for this call. This action interconnects these dlgital terminals.
S Channel Realiæation The control or S channel -transmissions are controlled by system processor lOO~ System processor 100 periodically scans each port, trunk and service circuit connected to switching network 101 to find if there is a control message for system processor 100. During each such scan cycle, system processor 100 transmits timing, address and control information to port data/control interface circuits 171-175 via I/O BUS. Each port data/control interface circuit (ex. 171) has a multiplexer which interprets the signals received on I/O BUS during each scan cycle and determines whether the address signals transmitted thereon identiy one of the port circuits (e.g. 111) served by that port data/control interface circuit (171). If such a match occurs during a scan cycle, port data/control interface circuit 171 enables the identified port circuit 111 to read the control message transmitted to port data/control interface circuit 171 by system processor 100.
Port circuit 111 reads the control message written into port/data control interface circuit 171 by system processor 100 and places the control message into a control message register (not shown) in port circuit 111. Port circuit 111 transmits this control message one bit at a time from the control message register to digital terminal interface module DTll.
Digital terminal interface module DTll assembles these serial bits into commands for digital terminal Tll.

Digital terminal Tll responds to these comma ~s by performi ~ the indicated operation, such as lighting a lamp, prod~cing an audible ring signal, etc.
IE digitaL terminal Tll has no reply or other control message to send back to system processor 100, digital termi ~1 interface module DTll transmits idle bits back to port circuit 111. If digital terminal Tll has a control message to send to system processor 100, it is written into the control message register of port circuit 111 one bit at a time. Port circuit 111 sets a data-ready bit in its status register (not shown) to indicate to system processor 100 that a control message has arrived from digital terminal Tll. System processor 100 periodically scans th3 port circuit status registers via I/O BUS and port data/control interface circuit 171 for a set data-ready bit. When one is found, system processor 100 reads the control mesisage stored in the control message register of port circuit 111 and resets the data-ready bit in the status register.
Port Circu ~ FIGS. ~-6 E'IGS. 4, 5 and 6, when arranged shown in ~IG. 7 disclose details o the port circuit with emphasis upon the port circuitry associated with the reception and generation of S bit signaling messages in the DCP frame format shown in FIG. 8. Additionally, details of this circuit are disclosed in U.S. Patent No. 4,534,023, issued August 6, 1985, to S. R. Peck et al.
The communication leads TR18 comprises a 160 kilobit per second data link to the associated terminal equipment, computer ~18. The 160 kilobit rate results from the fact that message segments of 20 bits (as shown in FIG. 8) are transmitted between 35 computer T18 and port circuit 118 at an 8 Kh~ rate.
Alternate bipolar modulation is used to transmit the data signals.

Receiver The operation of the receiving portion oE port circuit 11~ is first described. Message segments from computer T18 are received in the DCP fra~e format and applied over communication leads TR18 to line receiver gOl. Line receiver 401 derives its synchronization from the framing bits of each received message segment and passes the remaining fields (the S fiel~ and the two I fields) in serial form to frame demultiplexer 404 over lead 402. The synchronization circuitry of line receiver 401 generates a receive clock signal and applies it over lead 403 to the control portion of demultiplexer 404 as well as to receive formatter 407 and clock detector 408.
lS Line receiver 401 separates tha received signal from the noisy environment of the communication leads T ~ a and transforms it into a logic level signal that is applied to the input of demultiplexer 404.
Demultiplexer 40~ demultiplexes the S field and the two I Eields. The in~ormation in the two I fields comprises the data transmission from computer T18. This data transmission is extended over leads RIl and RI2 to multiplexer 405 which multiplexes the signals together and places them on time multiplexed bus PCM. Each I field occupies a di~ferent time slot on time multiplexed bus PCM and thus the information in each I field is transmitted out sequentially during each occurrence of its associated time slot. This information is applied to the time slot interchange ,l 30 facilities of the system which performs a conventional time slot interchange function and interconnects each I field with the port to which the call is directed.
The interface from the switch multiplexer 405 to the bus PCM contains both data and clock signals to control the switch multiplexer 405 and the switch demultiplexer 448.

, ~ rl-e S field information comprises one bit of the message segment of F~G. 8 and is applied over lead 460 to the receive formatter 407. Lead 460 comprises an eigh-t kilobit per second serial channel carrying the S field information. Receive formatter 407 performs ~he customary flag detection operation on this signal. That is, it looks for a pattern of a 0, followed by six l's and a 0, as shown on FIG. 9, and synchronizes to that pattern as long as the flags appear on lead 460. As soon as receive formatter 407 detects a nonflag sequencet as is the case when a signaling message character is received, it begins to perform a serial to parallel conversion on each nonflag byte.
During the time when nonflag characters are being received, receive formatter 407 performs a conventional zero delete function whenever it detects a sequence of five 1' 5 followed by a 0. It does this in accordance with the ~IDLC protocol in order to prevent a message character from being construed as the reception of a flag character. Receive formatter 407, while it is perfoxming this serial to parallel conversion on nonflag characters, also detects the reception of a flag character at the end of each message. It then generates a signal that is applied to lead 412 to specify the end of message for the received character. This path is also termed RCVE~ (Receive ~nd Of Message). Receive formatter ~07 applies each character after it is formed into a parallel format to leads 411 and from there to the receiver FIFO 414. ~eceiver formatter 407 also generates a signal that is applied to lead 413 to control the strobing of information into FIFO 414. The signal on lead 413 appears concurrently with -the signals on leads 411 and 412 so that they then can be strobed into FIFO ~14.
Receive FIFO 414 is organized as a 48 word, nine bit per word FIFO. The nine bits in each word are the eight bits representing the received character on _r,~ ~f~f ~b ;i~3 -- 1'1 --leads 911 and a one bit "end of me~sage" signal on lead 412 indicating whether or not each receive character does or does not represent the last character of a rllessage. The characters that are applied to the 5 input of receive FIFO 414 pass through in the conventional manner to the output of receive FIFO 414.
These eiyht bits are applied over leads 416 to tri-state gates 417. The end o~ message signal associated with each character is applied over lead 419 to counter 421.
10 The end of message signal is present only when the character is indeed the last character of a message and, at that time, the end of message signal increments counter 421 by a count of one.
Tri-state gates 417 are enabled by a read 15 register signal on lead 420. This signal is generated by system processor lOû and applied to port circuit 111 over I/O BllS via port data/control interface circuit 171 and leads DATA when system processor 100 wishes to read the contents of FIFO 414~ System processor 100 effects 20 this operation by applying a unique address siclnal over the above described path to address decoder 433 to cause it to gellerate an output on lead 42U extending to FIF0 414 and cJates 417~ Each port circuit, including port circuit 111 shown on FIGS. 4, 5 and 6, is assigned 25 a plurality of I/O BUS addresses. The various addresses represent the various functions of which the port circuit is capable. A particular function is initiated by the application oE the associated I/O BUS address to address decoder 433. Accordingly, in order to read out 30 a character from FIFO 414, system processor 100 applies the port address associated with lead 4 20 t o address decoder 433 via the DATA leads. Address decoder 433 responds to this address, drives lead 420 to cause the character at the output of FIFO 414 to be extended over 35 leads 416 and through gates 417 to leads DATA. This character is then passed through port data/control interface circuit 171 and over I/O BUS to system processor 100 which stores it and every other received character until a complete message is formed.
The read register lead 420 also extends to the OUTSTB termi ~1 of FIFO 414. FIFO 414 responds to the trailing edge of this signal and advances the next character stored within FIFO 414 to the output of FIFO 414 so that it can be read on the next read register operation. Thus, the read register signal on lead 420 performs two functions. The first is to enable gates 417 to pass the character currently on FIFO 414 output over leads 416, through gates 417 to DATA leads.
The trailing edge of the read register signal on lead 420 advances the next character within FIFO 414 to the output of FIFO 414~
The ninth bit in FIFO 414 is the END OF
MESSAGE bit on lead 41~. This signal performs two functions. The first function is to provide a READ END
OF MESSAGE s ignal to the input of the status gate 426.
Status gate 426 can be read by system processor 100 when it performs a READ STATUS REGISTER function on port circuit 111. Status gate 426 has a unique address and when system processor 100 applies this address to I/O ~US, the address is decoded by address decoder 433 which applies an enable signal over lead 42~ to activate status gate 42~. Status gate 42~ applies the signal present on lead 41~, to DATA 1 eads for transmission to system processor 100. The enabling of lead 429 enables all of the status register gates 424 through 42~.
The second function of the READ END OF MESSAGE
signal bit on lead 419 is to decrement receive message counter 421. Counter 421 at any time has a count in it that indicates the number of messages currently stored within FIFO 414. Counter 421 is incremented by a RECEIVE END OF MESSAGE signal on lead 412 and is decremented when a READ END OF MESSAGE signal is read out of FIFO ~14 on lead 41g. ThuS, the current count of counter 421 represents the number of complete messages currently stored within FIFO 414. The output of counter 421 on lead DR is the signal which permits a DATA READY indication to be read by system processor 100 as it scans status yates 424-428. The DR signal is exte~ed through gate 458 when lead 422 carries an enables signal and from there the signal extends over lead 406 to the input of the scan register gate 423 and to gate 425.
System processor 100 can read either scan register gate 423 or FIFO 414 by applying the appropriate addresses to I/O BUS. The address for either of these is decoded by address decoder 433. The appropriate output of address decoder 433 is enabled to activate the appropriate tri-state gate, such as 423 or lS 417, to allow data to be applied to DATA leads.
Transmit System processor 100 can generate and write messages into port circuit 11~ of FIGS. 4, 5 and 6 for transmission to computer T18. It does this by utilizing the write port:ion of port circuit 118. The first step system processor 100 per~orms on a port write operation is to determine whether transmit FIb'O 490 is full and is able to accept the message. If FIF0 440 is not full, system processor 100 writes the first byte of the message into port circuit 118. System processor 100 performs this function by first applying the appropriat~
address signal to I/0 BUS. The signal that is applied is that which is associated with the write portion oE
port circult 11~. Address decoder 433 decodes this address and generates the WREG signal on lead 435. This signal enables tri-state gate 434 which allows the message information now on I/O BUS to be extended through gate 434 and over lead 457 to the input of FIFO 44U. This signal on lead 435 is also applied to the INSTB input of FIEO 440 to strobe the message information currently on lead 45l into FIFO 440.

Also strobed into FIFO 44u at this time is the ninth bit, a WRITE END OF MESS~GE bit, which is applied to FIFO 440 over lead ~l3~. This signal indicates that the character associated with this bit is the last character of a transmitted message. System processor 100 sequentially writes eacn character of a message into FIFO 440. Just before the last character of the message is to be input into FIFO 440, system processor 100 writes into control register 431 via gate 432 and lead 459 to generate a WRITE END OF
MESSAGE signal on lead 436~ ~his signal is strobed into FIFO 440 at the same time the last byte of the message is strobed via the WREG signal on lead 435. The signal on lead 436 is automatically reset after the last byte is written into FIFO 440 by the trailing edge of the WREG signal on lead 435.
Transmit FIFO 440 is organized as a 48 word by nine bits per word FIFO. Eight of the nine bits represent the character information; the ninth bit of each word represents the absence or presence of a WRITE
END OF MESSAGE signal. Transmit FIFO 440 has a WRITE
BUFFER F~LL output termed WBF. When all 48 words in FIFO 4g0 are Eilled, the WB~ signal is extended over lead 430 to status register gate g27. This gate is periodically re~d by system processor 100 prior to writing FIFO 4 40. when FIFO 440 is full, the output of gate 427 advlses system processor 100 that FIFO 440 can accept no more bytes for the time being. If FIFO 440 i s detected to be full in the middle of writing a message, system processor 100 will queue the remainder of the message and throttle the load until a previously loaded message is transmitted and FIFO ~40 becomes sufficiently empty to accept at least one more byteO
The outputs of FIFO 440 are applied to lead 441 and 442. Lead 442 carries eight bits representing character information and lead 9~1 carries an END OF MESSAGE bit. FIFO 440 receives a strobe siynal from transmit Eormatter 445 over lead 44~. The character information on lead 442 and the END OF
MESSAGE s ignal on lead 441 are applied to the input of transmit formatter 4g5O Transmit formatter 495 normally continuously generates and sends out flag characters on the channel to the associated customer station as long as there are no messayes in FIFO 440. At such times, transmit formatter 445 sequentially generates a flag character of 0, six l's and a 0. Whenever EIFO 440 is not empty, transmit formatter 445 begins the process of unloading the characters from FIFO 440 and transmitting them out over the S channel. It does this hy performing a parallel to serial conversion on the received characters and the 2ero insertion function required for transparency. Thus, transmit formatter 445 first sends out flag characters when it determines from transmit FIFO 440 over lead 439 that FIFO 440 is not empty, then, at the end of transmission oE the flag character, transmit formatter 445 generates a strobe signal that is applied over Lead 443 to FIFO 440. This signal is used internally by transmit formatter 445 to load the character information on lead 442 and any END OE' MESSAGE signal on lead 441 into transmit formatter 445.
The trailing edge of this strobe signal is also used to advance FIFO 440 to bring the next character in FIFO 440 to the FIFO output.
Tran~smit formatter 445 performs a parallel to serial conversion on the received information. It also performs a zero insertion function when it is sending non-flag characters out over lead 446. That is, if the transmitted bit stream of the message has five consecutive l's, transmit formatter 445 inserts 3 0 between the fifth-l and the next bit transmitted. Thus, transmit formatter 445 transmits out each character it receives and it checks the END OF MESSAGE bit associated with each character. When the last character in a message is received from FIFO 440, lead 441 is set to a D~f~ ~ 3 1. Thls tells transmit formatter 4~5 that this character is the end of a messaye and causes transmit formatter 445 to insert a flag after this character.
Transmit formatter 445 does this and then checks for a transmit empty signal on lead 444. If the empty signal is present, transmit Eormatter 445 continues to generate and transmit flags. If the empty signal is not present, transmit formatter 445 then reads the next character out of FIFO 440. This new signal is a first character of a subsequent message. Transmit formatter 445 processQs any such first characters of the subsequent message, and all other characters of that subsequent message, in a manner similar to that already described.
System processor 100 can write an initialize bit into control register 431. This bit causes FIFOs 414 and 440 to be cleared as well as the message counters 421 and 438. This effectively removes all information from port circuit 118~
Lead 409 interconnects clock detector 408 with status register gate 424. Clock detector 408 normally receives clock pulses on lead 403 from line receiver 401. At such times, clock detector 408 applies a 0 over lead 409 to register gate 424. This permits system processor 100, when reading register gates 424-92~, to determine that clock pulses derived from thereceived data stream are being received over communication leads T ~ 8 by line receiver 401 and applied over lead 403 to clock detector 408. This is the normal operable state of the system. If/ for any reason, line receiver 401 fâils to receive a data stream, clock detector 408 receives no clock pulses and sets lead 409 equal to a 1 to permit system processor 100 to read gate 424 and determine -this condition. This condition could exist for example when the associated digital terminal Tll is disconnected from communication leads TRll.

Lead 422 interconnects the lower input of AND
yate 458 with control register 431. This path is normally held in an enabled state by control register.
This enables gate 458 and permi ts the DR output of counter 421 to be ~ ~tended over lead 406 to scan register gate 423. This DATA READY signal is used to advise system processor 100 that at least a single message is currently contained within receive FIFO 414.
Address decoder 433 contains Elip-flops so 10 that when an address is applied to the I/O BUS together with appropriate control signal by system processor 100, these control signals latch the address into -the decoder flip-flops. The output of these flip-flops extends to circuitry which decode the address and give output lS signals unique to each different address. One of these output signals extends to lead 4S9. This signal is active at the time that data appears on I/O BUS and is used to strobe the data into latches in control register 431. That data is persistent because it is 20 latched into control register 431. Control register 431 contains flip-flops which store the state of port circuit 111 as controlled by system processor 100, as subsequently described.
Transmit message counter 438 functions 25 similarly to receive message counter 421 to indicate whether FIFO 440 currently contains a complete message.
Transmit message counter 938 is incremented over lead 436 when a message is entered into FIFO 440.
Transmit message counter 438 is decremented over 30 lead 441 when a message is read out of FIFO 440.
The output of transmi t forma tter 445 extends over lead 456 to the frame multiplexer 449. Switch demultiplexer 448 receives PCM time slot signals on bus PCM, separates out the Il and I2 field signals Eor 35 use by port circuit 118 from their assigned time slots and applies them to leads 4 53 a nd 4 54. An o~tput of transmit messaye counter 438 extends to transmit ~ J~3 formatter ~45 on Lead 439 which indicates when the contents of transmit message counter 43~ is 0. This implie~ that no messages are contained in FIFO 440 and that transmit formatter 445 should generate flag characters.
The Il, I2 signals are received by frame multiplexer 449 together with the serialized S channel bits on lead ~56. Once each frame, frame multiplexer 449 inserts the eight bit Il field, the eight bit I2 field and the one bit S field into a framing signal and applies it over lead 452 to the line transmitter 450 which adds the F field bits. From there, resultant twenty bit Erame of FIG. 8 is extended over communication leads T ~ 8 to computer T18.
lS Line transmitter 45U and frame multiplexer 449 operate under control of the output signals from clock generator 455. Switch demultiplexer 448 receives its control signals from bus PCM.
Details of DCP Interface Card _ _ _ _ _ 2U DCP interEace card 201 is a processor controlled circuit which functions as a message handler and protocol converter. DCP interface card 201 converts the DCP signals of port circuit 151 and digital telephone station set TSl to data for PC ~US 207 and vice versa. The physical and link layer protocols are handled by the devices which comprise DCP interface card 201. DCP interface card 201 provides personal computer PCSl with access to and control of data and signaling both to and from the business communication systemO DCP interface card 201 looks to the business communication system like a digital phone with data and display modules while DCP interface card 201 looks to the digital telephone station set like a digital port board of the business communication system. Information from both the business communication system and the digital telephone station set associated with personal computer PC51 is transEerred to personal computer PC51 over a single multiplexed data channel. With access to and control of the signaling channel to the business communication system personal computer PC51 can implement advanced voice and data features in cooperation with the operation of the existin~ voice and data features on the business communication system.
FIG. 3 is a detailed block diagram schematic of DCP interface card 201. ~he major functional pieces of DCP interface card 201 as described above are illustrated in further detail in FIG. 3. These major component parts include telephone station set interface 202, bus communication controller 204 and business communication system interface 206. In addition to these major components FIG. 3 illustrates bypass switches 301 which function to directly connect the digital telephone station set to the communication leads T~51 in the case where personal computer PC51 is turned off or there is a power failure. External interface 302 is a connection shown to DCP interface card 201 which can be used for additional equipment such as a speaker phone, as will be described below. Digital signal processor 303 is a wired logic device which functions to perform call progress tone and Touch-Tone detection and Touch~Tone signal generation as will be described below.

The operation of DCP interface card 201 is controlled by a microprocessor shown on FIG. 3 as CPU 330. CPU 330 can be any state of the art ' 30 microprocessor such as a Motorola 68000 16 bit microprocessor. CPU 330 is a microprocessor that supports the high level C programming language. CPU 330 works off a vectored interrupt scheme to speed software response to interrupts. The main functions of CPU 330 are:

~ 2~

1) communicate with the business communlcation system over the S channel through -the switch S channel HDLC protocol and terminate levels 2 and 3 of the S channel terminal protocol,

2) send and receive data over the I2 channel of the HDLC protocol to -the business communication system and terminate levels 2 and 3 of this protocol,

3) communicate with the digital telephone station set over the S channel through the phone S
channel I~DLC protocol and terminate level 2 of this protocol,

4) control digital signal processor 303 to generate Touch-Tone signals or to detect both call progress tones and Touch-Tone signals,

5) control bypass switches 301 and the Il select and sync logic 323,

6) control timing and respond to interrupts used in protocol processing,

7) communicate with personal computer PC51 over PC BUS 207 to send and receive messages between DCP
interface card 201 and p~rsonal computer PC51 to send and receive information .for all the data channels described above.
Line Termination . .
In order to understand the operation of CPU 330 it is Eirst necessary to understand the operation of telephone statlon set interface 202 and business communication system interface 206. As was mentioned above, the communication leads TR51 and the communication leads from the digital telephone station set are terminated on bypass switches 301. Bypass switches 301 either connect the signals from the business communication system directly to the digital telephone station set or connect the signals from both the digital telephone station set and the business communication system to telephone station set interface 202 and business communication system . , -g~

interface 206 respectively. In this fashion, bypass switches 301 operate to perform a power failure transfer function. Bypass switches 301 are operated to directly connect the digital telephone station set to the business comm~nlcation system when personal computer PC51 is not turned on or not functioning properly or there is a power failure or DCP interface card 201 is not functioning properly. In all other cases bypass switches 301 are not operated and the communication leads TRSl is terminated on business communication system interface 206. In similar fashion, the communication leads from digital telephone station set T51 are routed through byp~ss switches 301 to terminate on telephone station set interface 202.
Both telephone station set interface 202 and business communication system interface 206 contain a DCP interface circuit identified on FIG. 3 as switch DLI 310 and phone DLI 320 respectively. Both switch DLI 310 and phone DLI 320 implement a DCP system interface as was described above in the discussion of port circuit 118. In particular, 5witch DLI 310 and phone DL~ 320 comprise line receiver 401, frame demultiplexer 404, clock detector circuit 408, line transmitter 450, frame multiplexer ~49 and clock generator 4S5 of FIG. 4 as described above for port circuit 11~. These elements operate as described above to terminate the DCP signaling protocol. The switch DLI 310 is configured in the terminal mode so that it appears as a digital telephone station set with display and data modules to the business communication system.
Phone DLI 320 is configured in the port mode so it appears as a digital port such as port circuit 118 to digital talephone station set T51. Both switch DLI 310 and phone DLI 320 separate the received DCP signals into the serial S, Il, and I2 channels and combine the transmitted serial S, Il, and I2 channels into the transmitted DCP signals as described above.

~ 3 -- ~5 --~Il and I2 Channel Signal_Routing The S, Il and I2 channels are all used in the DCP protocol transmi ssions between the business communication system and the DCP i nterface card 201 to 5 carry voice, control and data signals therebetween.
Between digi tal telephone station set T51 and DCP
interface card 201 only the Sl and the Il channels are used to transmi t control and voice signals. q~he S2 and I2 channels are not used with the digi tal telephone 10 s tation set because all data transmi ssions to and from the business comm~nication system are termi nated on personal computer PC51.
Signals carried on the Il channel are the voice communication signals which are transmitted 15 between the digi tal telephone station set and the business communication system. Therefore, the voice signals of the Il channel are not switched to personal computer PC51 in this describecl application. Il select and synchronization logic 323 functions to interconnect 20 the various sources and destinations Eor the Il channel voice signals. The voice signals can originate from digital l:elephone station set T51, from digital signal processor 303 as Touch-Tone signals, from the business communication system on communication leads TR51 or from 25 externaL interEace 302. The voice communication signals on the Il channel can be directed to digi tal telephone station set T51 from the business communication system or from the digital signal processor 303 or from external interface 302. Therefore, Il select and sync 30 logic 323 interconnects the voice communication signals from either the ~usiness communication system as separated by switch DLI 310 and applied to lead 313 or from external interface 302 and applied to lead 304 or from digital signal processor 303 and applied to 35 lead 305 to lead 321 which carries these voice communication signals to the phone DLI 320 where these voice signals are encoded into the DCP signaling format -æ~-and transmitted to digital telephone station set T51.
In similar fashion, voice communication signals can be directed to external interface 302 from either the business communication 5ys tem or digi tal telephone 5 station set T51. Il select and sync logic 323 receives the voice communication signals from the business communication system as decoded by swi tch DLI 310 and applied to lead 313 or from digi tal telephone station set T51 and decoded by phone DLI 320 and applied to 10 lead 321 and switches these signals to lead 304 where they are applied to external interface 302. Swi tch DLI 310 receives voice communication signals from external interface 302 or from digital signal processor 303 or from digital telephone station set T51 15 via Il select and sync logic 323. The remaining destination for voice communication signals is digi tal signal processor 303. Digital signal pr ocessor 303 is a wired logic processor which functions to decode call progress tones or Touch-Tone signals received from the 20 business communication system. These call progress tones and Touch-Tone signals are transmi tted by the business communication system over communication leads TR51 and decoded by switch DLI 310 and applied to leacl 313. I1 select and sync logic 323 switches the 25 received tones to lead 305 to digital signal processor 303 where these tones are detected and analyzed. The resulting control signals identifying the call progress tone or Touch-Tone signals are applied by digital signal processor 303 to lead 306 30 I/O Devices Devices 314, 315, 324 and 325 are serial input/ output devices each of which contains an independent full dupl ex serial data channel that is programmable for either synchronous or asynchronous 35 modes. These devices are commercially available input/output devices such as a MOS~EK MC6 8564P device.
Input/output devices 314 and 315 are programmed to handle the HDLC bit synchronous mode to process the switch S and I2 data channels. Input/output device 32 is progrdmme~ to the asynchronous mode to com~unicate with dic~ital signal processor 303 while input/output device 325 is programmed to the HDLC bit synchronous mode to handle the S channel for the digital telephone station set. The serial channels programmed for the HDLC mode have the following attributes:
1) automatic 0 insertion and deletion 2) automatic flag insertion between messages 3) abort sequence generation and detection 4~ internal flag cletection and synchronization 5) automatic cyclic redundancy check The asynchronous communication channel with digital signal processor 303 has the following at-tributes: six bits per character; one start bit; one stop bit; no pari-ty. Input/output devices 314, 315, 324, 325 contain control, status and data reyisters.
These devices generate interrupts when either the received data register contains data or the transmit data register needs data. CPU 330 responds to the interrupts yenerated by one oE devices 314, 315, 324, 325 and applied to CPU address control and data bus leads 203 by reading the contents of the received data register for a received interrupt and sending a character to the transmit data register for a transmit interrupt in the device generating the interrupt.
Thus, when digital signal processor 303 interprets call progress tones, the resultant control signals are loaded in the registers of I/0 device 324 and I/O device 324 generates an interrupt for CPU 330.
CPU 330 resp~nds to this interrupt by reading the data register indicating the call progress tone present on - 35 communication leads TR51 from the registers in I/O
device 324.

D~tal Signal Processor Digital signal processor 303 is programmed for three modes of operation, Touch-Tone generation and the detection of call progress tone or Touch-Tone signals.
CP~) 330 controls the operation of digi tal signal processor 303 via the registers in I/O device 324. In Touch-Tone generation mode, CPU 330 transmi ts a Touch-Tone comma~xl via CPU address, control and data bus 203 to I/O device 324. Digital signal processor 303 reads the Touch-Tone command from I/O device 324 and generates the Touch-Tone signals which are applied via lead 305 to Il select and sync logic 323. Il select and sync logic 323 forwards the generated Touch-Tone signals via lead 313 to switch DLI 310 which incorporates the generated Touch-Tone signals into the Il Eield of a DCP
signal which is applied to communication leads TR51 to the business communication system. In similar fashion, CP[~ 330 can apply control s ignals to CPU address control and data bus 203 to load call progress tone detection or Touch-Tone signal detection commands into I/0 device 324. Digital signal processor 303 responds to these loaded call progress tone detection or Touch-Tone signal detection commar~ls by monitoring the Il channel from the business communication system to detect the presence of call progress tones or Touch-Tone signals on communication leads TR51. This is accompl ished by switch DLI 310 decoding the Il channel signals from the DCP signals received from the business communication system, and aptL~lying the decoded Il signals to lead 313 ,l 30 to Il select and sync logic 323 which forwards the Il channel signals via lead 305 to digital signal processor 303. Digital signal processor 303 is capable of detecting busy signals, dial tone, reorder tone, ringing intercept tone, call confirmation tones and all Touch-Tone signals. Digital signal processor 303 generates a call progress tone detected message or a Touch-Tone detected message in the response to the presence of one of the above tones and loads the tone detected message into the received data registers of I/O
device 324 which device generates an interrupt for CPU 330. CPU 330 reads the tone detected message from I/O devlce 324 via CPU address control and data bus 203.
Memory anc3 Timin~
Read only memory 331 is the memory device on DCP interface card 201 which contains the instruction set for the operation of CPU 330. Random access memory 332 consists of the read/wr ite memory which is used by CPU 330 as read/wr ite memory space for transferring information to and from personal computer PC51. Local control and timer 333 and PC BUS
interface 334 is a commercially available chip such as the Motorola MC68230 parallel interface/t imer device.
This combined device generates all the asynchronous bus interface signals and generates interrupt vectors for the timer and the parallel I/O registers. The parallel interface portion of this device is programmed to the bidirectional eight bit mode. Pt: BUS interface 334 functions to provide a buffered interface between PC
BUS 207 and CPU address control and data bus 203.
Device Driver Protocol _____ S channel messages and I2 data from the business communication system and Sl channel messages from the adjunct telephone station set TSl as well as local control messages between DCP interface card 201 and device driver 211 are forma tted into message frames, multiplexed into a single data stream, and transmitted between DCP interface card 201 and interrupt service routine 212 of device driver 211 via PC BUS 207. Each message frame in this data stream is delineated by an address header byte which i5 followed by a message length byte. The actual message is located in the message frame following the message length byte. A
control register (not shown) in PC Bus interface 33~ of DCP interface card 201 gives device drivers 211 control _b~ !73 o;E both transmit and receive interr~pts as well as transmit and receive direct memory access. The message frames are transferred between DCP interface card 201 and device driver 211 on either a per byte basis using one interrupt per byte of data transferred or by direct ~memory access using one interr~pt per block of data transferred. PC Bus interface 334 contains both a transmit register (not shown) and a receive register (not shown) which are used to store the message frames transferred between DCP interface card 201 and device driver 211~
Device_Drivers 211 Device drivers 211 is a soEtware process that runs on processor 209 of PCSl. Device drivers 211 interfaces communication management application 210 with DCP interface card 201. As shown on FIG. 2, two software processes comprise device drivers 211.
Interrupt service routine 212 processes the data stream on PC BUS 207 and exchanges message frames between DCP
interface card 201 and communication management application 210 by storing/retrieving the message frames in memory 208. In similar fashion, application interface 213 transfers message Erames between communica~ion management application ~10 and memory 208 Interprocess communication path 214 is shown on FIG. 2 as interconnecting application interface 213 and interrupt service routine 212. This is a control message communication channel for passing control messages between application interface 213 and interrupt !' 30 service routine 212. ~he actual implementation of interprocess communication path 214 is typically by way of each process accessing an interprocess communication section of memory 208. The interprocess communication section of memory 208 functions as a "mailbox" with each of processes 212 and 213 placing/retrieving messages into/from interprocess communication section of memory 208. These mailbox messayes can be simply the setting of a flag or pointer for many communication applications.
Kee~ ive_Process A keep alive process is used by DCP interface card 201 to maintain telephone service between digital telephone station set T51 and the business co~munication system even if device driver 211 or communication management application 210 fail. The various modes of communication are schematically illustrated in FIG. 10.
Path 1010 indicates the normal or CMA mode of message flow while path 1020 illustrates a soft direct connect mode described below and path 1030 illustrates a direct j connect mode described below.
If communication between DCP interface card 201 and device driver 211 fails, DCP interface card 201 enters a direct connect mode so that digital telephone station set T5l is directly connected to the business communication system. Timer 333 on DCP
interEace card 201 runs continuously and is reset on each message received from device driver 211. The business communication system transmits an Sl channel message to each digital telephone station set every 6 to 12 seconds. These Sl channel messages are received by DCP interEace card 201 and forwarded to device driver 211 as described above. Device driver 211 forwards this Sl channel message, or a modified version of the message, or a response message to DCP interface card 201. Thus, this periodic Sl channel message maintains the keep alive process timer.
If device driver 211 fails to transmit a message to DCP interface card 201 within 13 seconds, timer 333 times out and CPU 330 transmits a local control message to device driver 211 to indicate that DCP interface card 201 is about to enter the direct connect mode. If device driver 211 respo ~ s to this local control message within 2 seconds, CPU 330 resets timer 333. If device driver 211 does not respond to . , this control message within 2 seconds, CP~ 330 activates bypass switches ~01 to directly connect digital telephone station set T51 to communication leads TR51 (path 1~30).
~nother level of keep alive process is where communication management application 210 fails but device driver 211 is functioning. This is called soft direct connect mode (path 1020). The soft direct connect mode is activated when device driver 211 is functioning and receive the above-mentioned local control message indicating that DCP interface card 201 is about to enter the direct connect modeO If communication management application 210 does not respond to this message, device driver 211 enters the soft direct connect mode and forwards all messages received without the intervention of communication management application 210.
Voice Originated Call From PC51 In order to better understand the operation of DCP interEace card 201 and dev.ice driver 211, the Eollowing description of a simple call connection is used to illustrate the operation of the above described elements which comprise DCP interface card 201 and device driver 2:Ll. Voice calls can be originated from PC51 in several different ways: keyboard d.ialing, mnemonic dialing, or directory dialing. For the purposes of this description, keyboard dialing will be used as an illustrative example.
A person (described below as user) accessing PC51 initiates à voice call by entering a number from the keyboard of PC51 and then pressing the carriage return key on the keyboard of PCSl. In response to the entry o this keyboard dialed number, communication management application 210 transmits an Sl channel (the voice control portion of the S channel) off-hook message to application interface 213. Application interface 213 responds to this off-hook message by enabling the transmit interrupt in the control register portion of PC
Bus interface 334 and changing buffer pointers via path 214 for interrupt service routine 212. Receive interrupts are always enabled. PC Bus interface 334 generates an interrupt when the transmit register is empty. Interrupt service routine 212 responds to the transmit register empty interrupt by forwarding the off-hook control message, which is temporarily stored in memory at the end of the transmit buffer, along with the appropriate address header byte and message length byte over PC BUS 207 to PC Bus interface 334 and thence through local control and timer 333 and over CPU
address, control and data bus 203 to CPU 330 on DCP
; interface card 201. Upon completion of the transmission lS of the off-hook message, interrupt service routine 212 disables the transmit interrupt in the control register of PC Bus interface 334.
Messaqe Transfer Between PC Bus and Communication Leads CPU 330 responds to the received off-hook messaye by forwarcling this message via CPU address, control and data bus 203 to HDLC device 315. As discussed above, HDLC device 31S in cooperation with switch DLI 310 formats and transmits DCP format message frames to the business communication system by way of ~S communication leads TR51.
Upon receipt of the off-hook message forwarded by CPU 330, the business communication system responds by transmitting a DCP message frame which contains an Sl channel lamp update message to DCP interface card 201 via communication leads TR51. This lamp update message is retrieved from the DCP message frame by switch DLI
310 and forwarded on lead 312 to HD~C device 315. CPU
330 retrieves the lamp update message from HDLC device 315 via CPU address, control and data bus 203. CPU 330 appends address header and messag~ length bytes to the lamp update message to create a message frame for PC51.
CPU 330 then generates an interrupt by way of PC bus J~
-- 3~ --interface 339 to device driver 211. Interr~pt service routine 212 of device driver 2 Ll responds to the receive interrupt by reading the lamp update message via interr~lpts and direct memory access from the receive register in ~C bus interface 334 where CPU 330 has forwarded the message frame containing the lamp update message. Interrupt service routine 212 stores the Sl channel lamp update message in a buffer in memory 208 for communication management application 210.
Communication management application 210 periodically polls application interface 213 and reads the stored lamp update message vi a application interface 213 which retrieves the lamp update message from memory 208.
Control Messa~e from PC51 to Telephone 5tation Set T51 Communication management application 210 responds to the lamp update message by updating the screen on PC51 to indicate to the user at PC51 that the off-hoolc signal has been received by the business communication system. Communication management application 210 also forwa rds the lamp update message to adjunct telephone station set T51 by way of DCP
interface card 201. This is accompl ished by communication management application 210 transmitting the lamp update message to application interface 213 2S which app~nds the appropriate address header and message length bytes and places this message in memory 208. As described above, application interface 213 enables the transmi t interrupt in the control regi ster portion of PC
Bus interface 334. Interrupt service routine 212 then ; 30 forwards the lamp update message by interrupts and DMA
to PC Bus interface 334 which forwards this message through local control and timer 333 and CPU address, control and data bus 203 to CPU 330. Upon completion of the message transmission, interrupt service routine 212 35 disables the transmi t interrupt in the control regi ster of PC Bus interface 334.

CPU 330 responds to the received lamp update messaye àesignated Eor telephone station set T51 by transmitting the Lamp update message via CPU address, control and data bus 203 to HDLC device 325 where the 5 lamp upàate message is forwarded to phone DLI 320 for formatting into a DCP message frame for adjunct telephone station set T51. As described above, phone DLI 320 transmits DCP format message frames to adjunct telephone station set T51 and the subject lamp update 10 messaye is transmitted as described above.
Dialed Number Processlng Communication management application 210 now processes the number entered by the user at PC5 1 through the keyboard. Communication management application 210 15 transmits the dial string entered from the keyboard to application interface 213, which parses the dial string and transmi ts the digi ts through a generate Touch-Tone control message through memory 208 and interrupt service routine 212 to CPU 330 via the transmit register as 20 described above. CRU 330 responds to the gen~rate Touch-Tone control message by transmi tting control signals via CPU address, control and data bus 203 to digital signal processor 303 as described above.
Digital signal processor 303 responds to the control 25 signals transmitted by CP[~ 330 by generating corresponding Touch-Tone signals on the Il channel for transmission to the business communication system. ~he Touch-Tone signals generated by digi tal signal processor 303 are forwarded over lead 305 to Il select and sync 30 logic 323 where the signals are routed over lead 313 to switch DLI 310. The Touch-Tone signals so routed are formatted into a DCP message frame for -transmission to the business communication system via communication leads TR51.

~L S~

Second Dial Tone If, as part of the dialing, a wait for the second di~l tone is needed, ~pplication interface 213 sets pointers and flags via interprocess control path 5 214 for interrupt service routine 212. Application interface 213 sends a call progress monitor control message via memory 208 and interrupt service ro~tine 212 to CPU 330. CPU 330 responds to the call progress monitor control message by placing digital signal processor 303 in a call progress monitor mode wherein digital signal processor 303 is connected by Il select and sync logic 323 to switch DLI 310 to monitor all signals received from the business communication system on communication leads TR51 to determi ne whether dial tone is present on communication leads TR51 in the Il field of the DCP message frames. When a dial tone signal is received from the business communication system in the Il field of a DCP message frame on communication leads TR51, this dial tone signal is routed in standard fashion by swi tch DLI 310 over lead 313 to Il select and sync logic 323 which forwards the dial tone signal over lead 305 to digital signal processor 303~ Digital signal processor 303 responds to the received dial tone by transmitting a control signal over lead 306, I/O device 324 and CPU address, control and data bus 203 to CPU 330 indicating that dial tone has been received. CPU 330 responds to this dial tone received signal by generating a dial tone received control message which is transmitted by PC Bus interface 334 to interrupt service routine 212~ In response to the received dial tone received control message, interrupt service routine 212 transmits the remainder of the dial string in control messages via PC ~us interface 334 to CPU 330. CPU 330 interprets the received dial string messages and generates signals to digital signal processor 303 which generates and transmits the appropriate Touch-Tone signals to Il select and sync logic 323. When all the Touch-Tone si~nals have been transmitted by diyital signal processor 303 to the business communication system via communication leads TR51, interrupt service routine 212 transmits a control message via PC Bus interface 33~ to CPU 330 to place digital signal processor 303 in a call progress monitor mode to determine the status of the call for feedback to the user~
Ringing the Cal.led Party ~ .
Once the business communication system receives the Touch-Tone signals corresponding to the complete dial string, the business communication system signals the called party and transmits the called party identification to DCP interface card 201 in an Sl channel display message. The called party display message is transmitted by the business communication system in a DCP message frame over communication leads TR51 to switch DLI 310. The S channel portion of the DCP message frame is forwarded by switch DLI 310 over lead 312 to HDLC device 315. ~s discussed above, CPU
330 retrieves the called party display message from HD~C
device 31.5 via CPU address, control and data bus 203.
CPU 330 responds to the received called party display message by appending the appropriate address header and message length bytes before transmitting the message to interrupt service routine 212. Interrupt service routine 212 reads the called party display message via interrupts and direct memory access and places the called party display message in a bufer in memory 208 for communication management application 210.
Communication management application 210 periodically polls application interface 213 and thereby obtains the called party display message from memory 208 via application interface 213. In response to the received called party display message, communication management application 210 updates the screen on PC51 to indicate to the user that the call has been placed to the -- 3~ --designated party. Communication management application 210 also forwards the called party display message to adjunct telephone station set T51 as was described above for the off-hook message.
The business communication system transmits periodic ring back tones on the Il channel of the DCP
message frames to DCP interface card 201 over communication leads TR51 to indicate that the called party is being rung. Digital signal processor 303 is in the call progress monitoring mode and responds to each received ring back tone by generating a control signal for CPU 330. CPU 330 responds to each call progress tone received by digital signal proeessor 303 by -transmi tting a control message vi a PC Bus in~erface 334 to interrupt service routine 212. This control message causes interrupt service routine 212 to transmi t a call progres~ monitor control message to CPU 330 to reset the timer. Interrupt service routine 212 will also pass the ring back informa tion to communication management appl ication 210 by way of interprocess con-trol path 214 to application inte~rface 213. Communication management application 210 displays ring bac:k information to the user by flashing the text "Ri nging" on the screen of PC51. 1'he user at PC51 can now piek up the handset on adjunet telephone station set T51 to be connected to the call or ean wa it for the called party to answer. If the user has turned on a speakerphone connected to external interface 3 02, the user hears ringback tone and is automatically conneeted to the called party when the called party answers the call by going off-hook.
Call Completion Assume for the purpose of this description that the user at PC51 picks up the handset on adjunct telephone station set T5 1. At this point, the user is conneeted from adjunet telephone station set T51 through phone DLI 320, Il select and sync logic 323, switch DLI
310 and the Il ehannel of communieation leads TR51 to the busin2ss communication system. When the called party answers, ring back tones are no longer placed on the Il channel of the DCP message frame s by the business communicdtion system. Since these call progress tones 5 are no longer present, digital signal processor 303 detects no tones and does not forwa rd a control 5 ignal to CPU 330. Since no call progress tone control messages are forwarded by CPU 330 to device driver 211, device driver 211 does not send any call progress 10 monitor control signal to CPU 330. Thus, CPI~ 330 times out and turns off digital signal processor 303 and then sends a control messaye to interrupt service routine 212 to indicate that digital signal processor 303 has been turned off. In this fashion, the call progress tone lS monitoring is disabled.
Call Termination Upon the compl etion oE the call, the user at adjunct telephone station set T51 goes on-hook. Adjunct telephone station set T51 responds to the on-hook 20 condi-tion by transmitting an Sl channel on-hook message to DCP interface card 201. Phone DLI 320 splits the S
channel message from the l-lDLC messaye Erame received from adjunct telephone station set T51 and transmits this S channel message over lead 322 to ~IDLC device 325.
25 CPU 330 reads the on-hoolc message stored in HDLC device 325 via CPU address, control and data bus 203. CPU 330 responcls to the on-hook message by generating a message frame which is transmitted by PC Bus interface 334 to interrupt service routine 212. Interrupt service 30 routine 212 buffers the on-hook message in memory 208 for communication management application 210 to read during its next periodic poll of application interface 213, Communication management application 210 then forwards the on-hook message to CPU 330 via PC Bus 35 interface 334 to be transmitted to the business communication system. CPU 330 responds to the on-hook message from interrupt service routine 212 by forwarding J.A~ J /~ 3 -- ~o --the on-hook message vi a CPU address, control and data bus 203 to HDLC device 315 which forwards the HDLC
framed on-hoolc message to swi tch DLI 310 for formatting into a DCP message frame for transmission to the business comm~nication system over communication leads TR51.
Final lamp update and display messages are transmitted to DCP interface card 201 by the business communication system in response to the on-hook message.
These lamp update and display messages are S channel messages which are received by DCP i nterface card 201 over communication leads TR51. Swi tch DLI 310 routes these S channel messages to HDLC device 315 where they are stored for access by CPU 330. CPU 330 reads the lamp update and display messages from HDLC d evice 315 and forma ts them with the appropriate address header and message length bytes into a message Erame for interrupt service routine 212. Interrupt service routine 212 s tores the lamp update and display messages in memory 208 Eor access by communication manayement application 210 during the next poll of applicatior interface 213 by communication management application 210. Communication managemenl. applicat:ion 210 responds to the lamp update and display messages by updating the screen on PC51 and by forwarding the lamp update and display information via application interface 213 and interrupt service routine 212 to CP[l 330 for forwarding as described above to adjunct telephone station set T51 to update the lamps on adjunct telephone station set T51.
The above description of a keyboard dialing originated call from PC51 can be replicated for mnemonic or directory dialing in similar fashion. In these two cases communication management application 210 responds to the information input by the user on the keyboard to access memory 208 to thereby retrieve a dial string associated with the mnemonic or directory entry input by the user via the keyboard. The resultant dial stream will then be processed as described above for the keyboard dialing case. In this fashion communication management application 210 can place a call using either the direct keyboard entry dialing or by performing a translation function from the directory identlfication or the mnemonic identification of a called party.
Data ~ Calls from PC51 The above description related to a voice call placed from PC51 to a called party. In similar fashion, a data call can be placed by a user at PC51 in one of several ways: keyboard dialing, mnemonic dialing or directory dialing. As above, keyboard dialing is selected as an illustrative example of a typical call origination setup sequence. The user at PC51 initiates a data call using keyboard dialing by entering a called party identification number from the keyboard of PC51 and then pressing the carriage return key on the keyboard o PC51. Communication management application 210 responds to the entered called party identification n~mber by transmitting a control message to application in~erEace 213 requesting that a data call be placed to the specified called party identification number using the specified baud rate. ~pplication interface 213 responds to this ~ata control message by transmitting an S2 channel (the data control portion of the S channel) off-hook message to the business communication system.
Application interface 213 sends the dial string and baud rate to interrupt service routine 212 via 214. This is accomplished as described above by application interface 213 enabling a transmit interrupt in the control register portion of PC Bus interface 334. DCP interface card 201 generates an interrupt when the transmit register portion of PC Bus interface 334 is empty.
Interrupt service routine 212 responds to this interrupt by transmitting the S2 channel off-hook message along with the appropriate address header and message length bytes via interrupts and direct memory access to CPU 330 -- ~2 --via PC Bus interface 334. Once this S2 channel off-hook message has been transmi tted, i nterrupt service routine 212 disables the transmi t interrupt in the control register of PC bus interface 334. CP[J 330 then 5 transmits the S2 channel off-hook message to HDLC device 315 via CPU address, control anc~ data bus 203. Switch DLI 310 reads the S2 channel control message from HDLC
devis~e 315, formats this control message into a DCP
message frame and transmi ts the resultant DCP message 10 frame to the business communication system over communication leads T R51.
Data Call Dialln~
. . .
The business communication system responds to the S2 channel off-hook message by returning an S2 15 channel dial tone message with the text "Dial:" to DCP
interface card 201 in the DCP message frames. This S2 channel dial tone message is routed by swi tch ~)LI 310 to HDLC device 315 where it is stored for retrieval by CPU
330. CPU 330 retrieves the S2 channel dial tone message 20 and appends the appropriate address header and message length bytes before generating an interrupt via PC Bus interEace 334 for interrupt service routine 212.
Interrupt service routine 212 reads the S2 channel dial tone message via interrupts and direct memory access and 25 responds to the S2 channel dial tone message by manipulating the called party identification number as received from application interface 213 into a format acceptable by the business communication system.
Interrupt service routine 212 updates dialing status to 30 application interface 213 via interprocess control path 214 for communication management application 210 to read. Interrupt service routine 212 transmi ts to CPV
330 this dial string in ASCII format at the rate of 5 digits per S2 channel message and, at the end of the 35 dial stream, interrupt service routine 212 apper3ds a carriage return character. CPU 330 forwards the received S2 channel message via HDLC device 315 and -~ .6 ~ 7~3 -- ~3 --switch DLI 310 over the S2 channel of the DCP Iressage frames to -the busi.ness communlcation system.
When the business communication system receives the carriage return character appended to the 5 end of the dial stream by interrupt service routine 212, the business communication system rings the called party and transmi ts an S2 channel ring back tone message wi th the text "Ringing" to DCP interface card 201. This received S2 channel ring back tone message frame is 10 routed by switch DLI 310 to HDLC device 315 where it is retrieved by CPU 330. CPU 330 appends the appropriate address header and message length bytes to the S2 channel ring back tone message and forwards the resultant message to interrupt service routine 212.
15 Interrupt service routine 212 updates dialing status to application interface 21:~ via interprocess control path 214 for communication management application 210 to read. Communication management application 210 reads the dialing status from application interface 213 and 20 displays the text "Ringing" on the display of PC51.
Data Call Completion The call remains in the ringing state until the called destination goes off-hook, at which time the business communication system transmits an S2 channel 25 ring back removed tone message wi th the text "Answered"
to DCP interface card 201. This message indicates that the called party has answered the data call. This S2 channel ring back remove tone me ssage is routed by switch DLI 310 to HDLC device 315 for retrieval by CPU
30 330. CPU 330 appends the address header and message length bytes to this contrcl message and forwards same to interrupt service routine 212. Interrupt service routine 212 updates dialing status to application interface 213 via interprocess control path 214 for 35 communication management application 210 to read.
Communication management application 210 reads status ~ia application interface 213 and displays "Answered"

text to the user. In response to the received S2 channel ring back remove tone message, interrupt service routine 212 transmi ts a control message to CPU 330 to initiate the appropriate data protocol code (which is 5 selected by the baud rate) on DCP i nteri~ace card 201.
The data protocol code runs on CPLl 330, terminates levels 2 and 3 o~ the data protocol and provides a data interface between serial HDLC device 315 and interrupt service routine 212.
The data protocol code will handshake with the remote data module on the I2 channel by sending and receiving control messages via 314, 311, and 310. When the data protocol code of DCP interface board 201 and that of the remote data modul e determi ne that they are 15 compatible, CPU 330 transmits a control message to interrupt service routine 212 indicating that the call setup was successful and interrupt service routine 212 responds by transmi tting an S2 channel handshake success message to the business communication system. Interrupt 20 service routine 212 transmits the S2 channel handshake success message to CPU 330 for formatting and transmission to ~he business communication system via ~IDLC clevice 315 and swi tch DLI 310. Interrupt service routine 212 also transmi ts the control message received 25 from DCPI via application interface 213 to communication management application 210. In response to this received mesSacJe~ co{nmunication management application 210 updates the screen on PC51 to "active".
One example of a data transfer situation is 30 where communication managemer.~ application 210 is used for terminal emulation purposes. In this case, the user at PC51 enters data from the keyboard of PC51 and communication management application 210 transmits the data through application interface 213 and interrupt 35 service routine 212 (which appends the address header and message length bytes) to the data protocol code which resides on CPU 330. The data protocol code t'' - ~5 -transmits only the data using the appropriate framing on the I2 channel to the remote data module via HDLC device 314 and switch DLI 310~ Data is received on communication leads TR51 from the remote module and is routed by switch DLI 310 to HDLC device 314. This I2 channel data is read by CPU 330 via CP~ address, control anc3 data bus 203. CPU 330 forwards this feceived data with address header and message length bytes to interrupt service routine 212 which passes only the data via application interface 213 to communication management application 210. The data received by communication management application 210 is either displayed for the user on the screen of PC51 or stored in a file in memory 208.
Data Call Disconnect At the end of the call, the user at PC51 requests a disconnect. Communication management application 210 responds to the user's disconnect signal by transmitting a disconnect control message to application interface 213 requesting a disconnect.
Application interface 213 transmits a control message through interrupt service routine 212 to CPU 330 to terminate the data protocol code. CPU 330 returns a control message to interrupt service routine 21~ to ind1cate that the data protocol code is terminated.
Interrupt service routine 212 responds to the data protocol code terminated message by transmitting an S2 channel on-hook message to the business communication system via CPU 330, HDLC device 315 and switch DLI 310.
Interrupt service routine 212 then returns to the idle state.
For mnemonic and directory dialing, communication management application 210 replaces the keyboard input from the user in mnemonic or directory form with a dial string and then proceeds as discussed above with respect to the case of keyboard dialing.

Incomln~ Calls_to PC51 Incoming calls to PC51 are processed in similar fashion to outgoing calls as described above.
The business communication system on an incoming voice call transmits the following messages to DCP interface card 201: an Sl channel ringer on message; an Sl channel display message with calling party identification; an Sl channel lamp update message.
These messages are carried as part of the HDLC message frames on communication leads TR51 to switch DLI 310 where they are routed to HDLC device 315. CPU 330 sequentially retrieves these messages from ~IDLC device 315 via CPU address, control and data bus 203. CPU 330 appends address header and message length bytes to each message then generates an interrupt to interrupt service routine 212 via PC Bus interface 334. Interrupt service routine 212 reads the message via interrupts and direct memory access and stores each received message sequentially in memory 208. Communication management Z0 application 210 retrieves these messages in sequential fashion by periodically polling appllcation interface 213 whlch retrieves the messages from memory 20~.
Communication management application 21U responds to each message so received by updating the screen of PC51 and simultaneously ~orwarding the message to adjunct telephone station set T51. Communication management application 210 routes the message via application interface 213, interrupt service routine 212 to CPU 330.
CPU 330 responds to each message forwarded by communication management application 210 by determining ; the identity of the destination for this message, in this case adjunct telephone station set T51, and forwards the Sl channel message via CPU address control and data bus 203 to HDLC device 325. Phone DLI 320 retrieves the Sl channel messages stored in HDLC device 325 and formats these messages into a DCP frame and transmits same to the adjunct telephone station set T51.

'73 Adjunct telephone station set T51 responds to the Sl channel ringer on message by generating an alerting tone to indicate to the user at PC51 that an incoming call has arrlved. In addition, the Sl channel display message of a calling party ID causes adjunct telephone station set T51, if equipped with a display, to indicate the identity of the party calling the user at adjunct telephone station set T51. The Sl channel lamp update message causes adjunct telephone station set T51 to light the appropriate call indication. The user at PC51 can answer this call by picking up the handset on adjunct telephone station set T51. This action causes adjunct telephone station set T51 to transmit an Sl channel off-hook message to phone DLI 320 which routes this control message to HDLC device 325. CPU 330 retrieves the Sl channel ofE-hook message via CPU
address, control and data bus 203, appends the appropriate header and message length bytes to this message and forwards the resultant control message to interrupt service routine 212 via PC Bus interface 334.
lnterrupt service routine 212 responds to the received Sl channel off-hook message from adjunct telephone station set T51 by storing the oEf-hook message in memory 20~ for communication management application 210 to read via application interface 213 and forwarding this Sl c~annel ofE-hook message to the business communication system. Interrupt service routine 212 transmi ts the Sl channel off-hook message with the appropriate header and message length bytes to CPU 330 via PC Bus interface 334. CPU 330 decodes the header portion of this message to determi ne the destination for this control message. CPU 330 forwards the message via CPU address, control and data hus 203 to HD~ device 315. Switch DLI 310 retrieves the Sl channel off-hook message from HDLC device 315 and formats this message into a DCP frame and transmits the resultant frame to the business communication system over communication 5~3 leads TR51 to indicate to the busir~ess communication system tllat the user at adjunct telephone station set T51 has go~e off-hook. The conversation between the user at adjunct telephone station set T51 and the originatin~ party continues until one of the parties goes on-hook at which time the call is terminated as discussed ~bove for the case of the call originated by PC51.
Incoming data ca:Lls to PC51 are similar in operation to an incoming voice call described above.
For an incomil~ data call, the business communication system transmits an S2 channel ringer on message to DCP
interface board 201. Switch DLI 310 routes the S2 channel ringer on message to HDLC device 315 where it is stored for retrieval by CPU 330. CPU 330 appends the appropriate header and message length bytes to this received S2 channel ringer on message and forwards the resultant message frame to interrupt service routine 212 by way of PC BUs interface 33~. If the user has specified ln the communication management application ~lO that auto answer is on, this status information is passed by c~nmuni.cation management application 210 to interr~pt service routine 212 via application interface 213 and interprocess communication path 21~. Interrupt service routine 21~ automatically answers the call by transmitting an S2 channel oEf-hook message to the business communication system. Interrupt service routine 212 transmits the S2 channel off-hook message with the appropriate header and message length bytes to CPU 330. CPU 330 decodes the header portion of this message to determine the destination to which this message is intended and forwards the control message over CPU address, control and data bus 203 to ~IDLC
device 315. Switch DLI 310 retrieves the S2 channel off-hook message from HDLC device 315 and formats this ~ message into a DCP message frame and forwards the frame ; to the business communication system over communication .:

leads TR51. The business comrnunication system responds to the received S2 channel off-hook message by transmitting an S2 channel ringer off message with the text "Answered" to DCP i nterface card 201. Switch DLI
310 routes this S~ channel ringer off message to HDLC
device 315 where it is retrieved by CPU 330. CPU 330 appends the appropriate header and message length bytes to this S2 channel ringer off message and forwards the resultant message frame to interrupt service routine 212 by way of PC sus interface 33~. Interrupt service routine 212 responds to the received S2 channel ringer off messaye from the business communication system by automatically sending a control message to CPU 330 to initialize the data protocol code. The remaining portion of the call setup sequence is as described above Eor a data call originated at PC51. When the connection is complete, the data communication between source and destination continues until one party terminates the call at which time the call is broken down as described above for a data call originated by PC51.
Calls q'o and From ~unct ~ hone Station Set q~he processing of originating voice and data calls from adjunct telephone station set T51 is similar to voice and data calls originated from PC51. The only significant difference is that data calls can be originated only when bypass switches 301 are in the direct connect mode and also that the originating stimulus is generated by adjunct telephone station set T51 and routed by phone DLI 320 to HDLC device 325 where it is stored for retrieval by CPU 330. CPU 330 appends the appropriate header and message count bytes to these call origination messages then forwards them to interrupt service routine 212. Interrupt service routine 212 forwards the received Sl channel (for voice originated calls) control messages to memory 20~ and application interface 213 for communication management application 210. Communication management application - 5~ -210 up~ates the screen on PC51 to indicate the call origination status of ad~unct telephone station set T51.
The processing of the remainder of this originated call is identical to that described above for calls originated from PC51.
Incoming voice or data calls to adjunct telephone station set T51 are processed identically to incoming calls for PC51 as described above. The only difference is that data calls can be received only when bypass switches 301 are in the direct connect mode between the business communication system and the adjunct telephone station set T51.
Integrated_Calli~_Directory Application The communication management apparatus described above can 'oe used with various application processes to provide various business communication services to the user of digital telephone station set T51 and personal computer PC51. The subject application is an integrated calling directory feature which is implemented as a software process on personal computer PCSl. ~ conceptual illustration of this feature is shown on FIG. 2 where the communication ; management application 210 communicates with directory process 216 over interprocess communication path 217.
: 25 The directory process 216 is a software routine described below that provides integrated directory services to the user of personal computer PC51.
Directory process 216 is invoked by the user by way of control commands passed to communication management application 210 from the keyboard of personal computer PC51.
Call Management Displ~y FIG, 11 illustrates a communication management display that appears on the screen of personal computer PC51. This call management display is an ; emulation in pictorial form of -the buttons and functions of digital telephone station set T51. ~ile screen illustrated on FIG. 11 is divided into four windows labeled 1111-1114. I'he first of these windows, 1111, encompasses the top portion of the screen and illustrates two columns of button designations labeled Fl to FU. The button designations Fl to FU represent the line appearance and function buttons normally found on digital telephone station set T51. The left-hand column oE button designations Fl through F9 represent four line appearances Fl to F7 which are multiple appearances of extension 4479. An can be seen from FIG. 11, the designation "IDLE" appears to the right of the call appearances~ to indicate that these line appearances are idle. Button F9 represents the data line associated wlth digital telephone station set T51 which is extension 6248. The letter D which appears after the extension number for hutton F9 indicates that this is a data line. The busy/idle designation "ACTIVE"
which appears after the D associated with button F9 indicates that this line is presently active and the user has dialed a computer using this line appearance for PC51. Function buttons F2, F4, F6, F8 and F0 represent feature buttons tnat are found on digital telephone station set 'r51. These feature buttons indicate the standard functions that can be performed by 2S a single button push on a digital telephone station set.
Just below window 1111 is a horizontal line of characters running from the left side to the right side of the screen to delimit the next two windows which are windows 1112 and 1113. Window 1112 represents a number of additional feature/function keys that can be activated on a typical digi-tal telephone station set such as T51. The designations for these ten buttons are AFl to AF0. The letter A indicates that these functions are activated by depressiny the ALT button on the terminal keyboard of personal computer PC51 while concurrently depressing an associated function key Fl to F0 which appears on the keyboard of personal computer PCSl. Thus, if the user at personal computer PC51 wishes to activate the send all calls feature the user would depress the ~LT key while also depressing the F3 function key to activate the ~F3 function of send all calls. In similar fashion, window 1113 illustrates a calling directory arrangement which displays ten entries labeled SFl to SF0. The user at personal computer PC51 would activate the SHIFT key while concurrently depressing one of the function buttons Fl to F0 to select one of the directory entries illustrated in window 1113. The operation of this feature will be discussed in further detail below. The remaining window is 1114 which illustrates a directory entry and search menu which the user can activate as will be discussed below.
Functional Description of Callin~ Directory Function FIG. 12 illustrates in flowchart form the directory process 216. The Eirst step in directory process ~16 is labeled as step 1210 on FIG. 12. This firs~ step indicates that the user selects a directory entry function key or types a name/mnemonic from the keyboard. This indicates that the user at personal computer PC51, while viewing the display illustrated on FIG. 11, can either select one of the function keys illustrated in window 1113 to select a particular called party from the list of ten destinations shown on FIG. 11 or type in a separate name or mnemonic description of a called party from the Iceyboard, which entry would appear in window 1111 directly following the identifier "IDLE:"
' 30 which appears to the right of the selected call appearance. Once the user selects either a directory entry or types in an entry from the keyboard, directory process 216 enters s-tep 1211 where directory process 216 makes a determination whether the user has activated one of the ten function keys or has directly entered a new called party designation from the keyboard. Assume for the moment that the user has selected function key SF3.

~ 3~ ~3 Directory process 21~ identlfies the aCtlvation of function key S~3 and control in directory process 216 ~lows to step 121~ where directory process 216 copies the directory entry number from memory associated with the called party designated by ~unction key SF3 into a dialiny buffer (not shown). Directory process 216 has stored therein a correspondence between the called party O.L. AUER designated by function key SF3 and a dial string whlch, when outpulsed to the busine~s communication system, causes a communication connection to be established from personal computer PC51 to the identified called party. Directory process 216 advances to step 1213 once the directory entry dial string is placed in the dialing buffer. Step 1213 entails directory process 216 making a determination whether this is a voice call or a data call. If this were a voice call, directory process 216 would advance to step 121~ and perform a voice call setup as is described above. Once the voice call is established, directory process 216 exits at step 1215. In the present example it is assumed that this call is not a voice call but is a data call. Directory process 216 advances to step 1216 to perorm data call setup. This process is also described above but will be summarized here. The call setup function for a data call involves steps 1217 and 121~. In step 1217, directory process 216 invokes the terminal emulator software. The data module-to-data module "handshaking" of the low levels of th~ data protocol is handled as described above by DCP interface card 201, in the discussion of data call origination from personal computer PC51 to a computer connected to another port circuit on business communication system.
The terminal emulator software is invoked once the preliminary handshaking is accomplished and processes the hiyher levels of the data protocol. These levels are typically called the presentation layer and include positioning the cursor on the screen an~ determining the 2~3 video screen attributes. Directory process 216 also invokes script file processor in step 1218 which takes the script ~ile associated with the directory entry of SF3 and uses that to establish a communication 5 connection to the called party. Once this communication connection is established, directory process 216 exits at step 1215.
In the case at step 1211 where the user at personal computer PC5 1 has not depressed a function key 10 but instead has typed in an entry from the keyboard of personal computer PC51, directory process 216 proceeds to step 1219. Directory process 216 in step 1219 searchs the directory store~l on personal computer PC51 to match the -typed entry from the keyboard of personal 15 computer PC51 with the the entry stored in memory. The search can be by typed name or a mnemonic, which is an abbreviation used to identify a called party. This abbreviation can be an acronym or an identification of the particular status or Eunction of the called party.
20 Thu5, for example, typing "gùard" as a mnemonic could be translated by personal computer PC51 into a request for a call connection to the security organization of the particular company for which the user at personal computer PC51 works. Directory process 216 upon 25 locating an entry in memory that corresponds to the typed entry from the keyboard of personal computer PC51 branches at step 1220 to step 1212 to perform the call establishment function as described above. If no entry corresponding to the typed entry from the keyboard of 30 personal computer PC51 is located, directory process 216 exits at step 1215 and returns control to the user.
Directory Editlng FIG. 13 illustrates the screen used by the user of personal computer PC51 to create or edit 35 directory entries. This screen is invoked by the user selecting the directory edit Eunction from the screen illustrated in FIG. 11. This is accompl ished by actlvating the ALT button on the keyboard and opera~ing the E key on ~he keyboard which corresponds to the first letter of the function EVIT ~I~ to identify edit directory. In the arrangement illustrated herein windo~ 1114 contains on the very bottom from left to right a menu of various functions that can be performed.
These functions are labeled SEARCH, CLE~R, ~LLDIR, PHONE, ~IESSAGE, LOG, EDIT DIF~, OTHER. Each function is accessed by operating the ~LT key on the keyboard while concurrently operating the key corresponding to the first letter of the function identified in the bottom line of window 1114. Thus, the user at personal computer PC51 would activate the edit directory function by concurrently operating the ALT and E keys on the keyboard of personal computer PC51. Once the user operates these keys, directory process 716 erases windows 1112, 1113, 1114 and instead presents the user with window 1312 as illustrated on FIG. 13. Window 1312 is a directory editing window which contains identifiers of the various eleme~nts of data that are required to create a directory entry. The first line of window 1312 is prompted for the user to enter the name, group identiEication and designation of voice or data call corresponding to a new directory entry. Thus, the called party's name and an identification of the particular organization or group with which they are associated are entered on the first line of window 1312.
On the right hand side of the first line of win~ow 1312 is a question prompt for the user to desiynate whether a call originated from personal computer PC51 to this identified destination would be a voice call or a data call. This enables personal computer P~51 to perform data call setup using stock terminal emulator and script file processing when the destination identified in this particular directory entry is a computer~ The second line of window 1312 contains a prompt labeled "number"
which indicates the place where the user should enter ,73 the dial string required to contact the called party.
In addition a prompt labeled "dialing mnemonic" is shown on the second line which permits the user to designate a shorthand version of the called party's identi~ication.
The third line of window 1312 contains a prompt labeled "address" which provides a place for the user to enter a mailing address for the called party. The fourth line of window 1312 contains the prompt "electronic mail address" which permits the user to designate an electronic mail box on a destination computer to which electronic mail messages can be transmitted by personal computer PC51 for receipt by the d~signated user. The fifth line of window 1312 contains the prompt "comment"
and provides the user with space to enter specific comments concerning the called party which may be pertinent to the user when calling up this directory entry. These comments could be customer contact information or personal information concerning the called party which the user wishes to remember and have available when the directory entry associated with the called party is called Eorth. At the bottom of window 1312 is again located a list of menu items which the user can invoke by simply concurrently depressing the ~LT key on the keyboard of personal computer PC51 as well as the first letter of the function designation in window 1312. The left most entry in the bottom line of window 1312 is EDIT DIR which indicates the current mode of directory process 216. ThiS entry indicates to the user that the edit directory function has been invoked and directory process 216 is awaiting data entry for all of the elements illustrated in window 1312. The user can terminate the edit directory function by simply activating another of the listed functions.
Centralized Directory -If a directory search fails in the local PC
directory, a centralized corporate directory residing on another adjunct processor attached to the business communication system is searched. This search can be performed in ei-ther o~ two ways described below.
First, the directory process 216 on personal computer PC 51 emulates a h~man user of the centralized 5 corporate directory. That is, d irectory process 216 dials up the attachéd ad~unct processor (not shown) (step 1221) and performs the login procedure required of that adjunct processor. The PC d irectory process 216 then invokes a directory search process on the attached 10 adjunct processor (step 12~2) (not necessarily the same directory search process the human user would invoke) which searches the centralized corporate directory database using the name/mnemonic origi nally supplied by the PC user. When a ma tch is found by the directory 15 search process (step 1223), the telephone number associated with the name/mnemonic is ava ilable to the PC
directory process 216 to dial the called party as described above. This approach requires no change to the business communication system softwa re. Directory 20 process 216 on personal computer PC51 simply "dials up"
the adjunct processor via the business communication system swi tching network and performs a processor-to~
processor data trans~er.
An alternative approach to the problem of 25 searching a centralized corporate directory is to enhance the DCP S-channel message set to include two new messages. One S-channel message allows the ~C directory process 216 to send the business communication system the name/mnemonic to be searched in the centralized 30 corporate directory. This is accomplished by transmitting the name/mnemonic to be searched as an S-channel message (step 1221) to the business communication system, system processor 100 as described above. The system processor 100 in response to this S-35 channel message accesses the adjunct processor and usesthe received name/mnemonic to retrieve the called party identification associated with the received nc~me/mnemonic (step 1222). A second message is sent by system processor 100 to PC 51 which contains the number associated the previously sent name/mnemonic in the centralized corporate directory. This approach has two strony advantages: (1) user response time is faster since there is no requirement to dial-up the adjunct processor that the centralize~ corporate directory resides on; (2) with appropriate modifications in the DCP S-channel message set and the business communications system software, the centralized corporate directory search could be requested in an identical way by PC directory process 216 on any centralized directory arrangement on the business communication system. Thus, the centralized directory can be located on an adjunct processor or even in system processor 100. It is also immaterial to directory process 216 how the adjunct processor is converted to system processor 100. Directory process 216 simply passes control of the directory search to system processor 100 via the S-channel messages.
; While a specific embodiment of -the invention has been disclosed, variations in structural detail, within the scope~ oE the appended claims, are possible and are contempLated. There is no intention of limitation to what is contained in the abstract or the exact disclosure as herein presented. The above-described arrangements are only ilLustrative of the application of the principles of the invention.
Normally, other arrangements may be devised by those ! 30 skilled in the art without departing from the spirit and the scope of the invention.

Claims (13)

Claims:

1. In a business communication system which serves a plurality of terminal devices, each of which is connected to the business communication system by an associated port circuit, said business communication system including at least one centralized calling directory file for storing a list of called parties and their telephone numbers, calling directory apparatus associated with one of said terminal devices for automatically originating a call through said business communication system to a called party designated by a user at said one terminal device comprising:
processing means;
means interposed between said one terminal device, its corresponding port circuit and also connected to said processing means for connecting said processing means to both said port circuit and said one terminal device;
calling directory file means in said processing means for storing a list of called parties and their associated telephone numbers;
means in said processing means responsive to said user entering the name of said called party into said one terminal device for sequentially scanning said calling directory file means and said centralized calling directory using said name of the called party to obtain the telephone number of said called party;
means in said processing emans for originating a communication connection to said called party via said connecting means in response to said scanning means locating the name of said called party;
adjunct processing means connect to said business communication system via one of said port circuits for storing a centralized list of called parties and their associated telephone numbers;
means in said originating means responsive to said scanning means failing to locate an entry in said calling directory file means corresponding to said name of the called party for establishing a communication connection to said adjunct processing means via said connecting means; and means in said originating means responsive to said communication connection for querying said adjunct processing means to obtain the telephone number associated with said name of the called party from said centralized list.

2. The system of claim 1 wherein said originating means includes:
means responsive to said querying means for placing a telephone call to said called party using the telephone number obtained by said querying means from said centralized list.

3. The system of claim 1 wherein said business communication system includes a system processor connected to said port circuits, said calling directory system further comprising:
means in said system processor for storing a centralized list of called parties and their associated telephone numbers; and means in said originating means, responsive to said scanning means failing to locate an entry in said calling directory file means corresponding to said name of the called party, for querying said system processor via said connecting means and said port circuit to obtain the telephone number associated with said name of the called party from said centralized list.

4. The system of claim 1 wherein said business communication system includes a system processor connected to said port circuits which stores a centralized list of called parties and their associated telephone numbers, said calling directory system further comprising:

means in said originating means, responsive to said scanning means failing to locate an entry in said calling directory file means corresponding to said name of the called party, for querying said system processor via said connecting means and said port circuit to obtain the telephone number associated with said name of the called party from said centralized list.

5. The system of claim 3 or 4 wherein said originating means includes:
means responsive to said querying means for placing a telephone call to said called party using the telephone number obtained by said querying means from said centralized list.

6. The system of claim 1 further comprising:
means in said originating means responsive to said scanning means for placing a telephone call to said called party using the telephone number obtained by said scanning means from said calling directory file means.

7. In a business communication system which serves a plurality of terminal devices, each of which is connected to business communication system by an associated port circuit, said business communication system including at least one centralized calling directory file for storing a list of called parties and their telephone numbers, calling directory apparatus associated with one of said terminal devices for automatically originating a call through said business communication system to a called party through said business communication system to a called party designated by a user at said one terminal device comprising:
processing means;
means interposed between said one terminal device, its corresponding port circuit and also connected to said processing means for connecting said processing means to both said port circuit and said terminal device;
calling directory file means in said processing means for storing a list of called parties and their associated telephone numbers;
means in said processing means responsive to said use entering a mnemonic identifier associated with said called party into said one terminal device for sequentially scanning said calling directory file means and said centralized calling directory using said mnemonic identifier to obtain the telephone number of said called party;
means in said processing means for originating a communication connection to said called party via said connecting means in response to said scanning means locating the name of said called party;
adjunct processing means connected to said business communication system via one of said port circuits for storing a centralized list of mnemonic identifiers associated with called parties and their associated telephone numbers;
means in said originating means responsive to said scanning means failing to locate an entry in said calling directory file means corresponding to said mnemonic identifier associated with said called party for establishing a communication connection to said adjunct processing means via said connecting means; and means in said originating means responsive to said communication connection for querying said adjunct processing means to obtain the telephone number associated with said mnemonic identifier associated with said called party from said centralized list.

8. The system of claim 1 wherein said originating means includes:
means responsive to said querying means for placing a telephone call to said called party using the telephone number obtained by said querying means from said centralized list.

9. The system of claim 7 wherein said business communication system includes a system processor connected to said port circuits, said calling directory system further comprising:
means in said system processor storing a centralized list of mnemonic identifiers associated with called parties and their associated telephone numbers; and means in said originating means, responsive to said scanning means failing to locate an entry in said calling directory file means corresponding to said mnemonic identifier associated with said called party, for querying said system processor via said connecting means and said port circuit to obtain the telephone number associated with said mnemonic identifier associated with said called party from said centralized list.

10. The system of claim 7 wherein said business communication system includes a system processor connected to said port circuits which stores a centralized list of called parties and their associated telephone numbers, said calling directory system further comprising:
means in said originating means, responsive to said scanning means failing to locate an entry in said calling directory file means corresponding to said mnemonic identifier associated with said called party, for querying said system processor via said connecting means and said port circuit to obtain the telephone number associated with said mnemonic identifier associated with said called party from said centralized list.

11. The system of claims 9 or 10 wherein said originating means includes:
means responsive to said querying means for placing a telephone call to said called party using the telephone number obtained by said querying means from said centralized list.

12. The system of claim 7 further comprising:
means in said originating means responsive to said scanning means for placing a telephone call to said called party using the telephone number obtained by said scanning means from said calling directory file means.

13. In a business communication system which serves a plurality of terminal devices, each of which is connected to the business communication system by an associated port circuit, said business communication system including at least one centralized calling directory file for storing a list of called parties and their associated telephone numbers, at least one of said terminal devices having calling directory apparatus interposed between said one terminal device and said business communication system a calling directory method for automatically originating a call through said business communication system to a called party designated by a user at said one terminal device comprising the steps of:
sequentially scanning, in response to the entry of the name of said called party into said one terminal device, the calling directory file of said calling directory apparatus and said centralized calling directory to obtain the telephone number associated with said name of said called party; and originating a communication connection from said one terminal device to said called party using said telephone number obtained from said calling directory file.