the module builder needs to know is what performance regard to competition which gives a price/performance
the module unit is capable of carrying out and this can solution which is best for him without losing the possi
be indicated by the system designer at an early stage. By bility of standardised connection of modules to the
means of the invention, it becomes possible to imple- system. According to the invention, the physical stock
ment more sophisticated solutions for the bus connec- 5 ^ reieased from the different modules at the same time
tion as such than has previously been possible. The ^ simple structural possibilities for the communication
module builder can work with minimised knowledge of line are brought about m a simple manner. The parts
the system. In a case with a microprocessor in the con- which ^ ^ ^ for the hysical stock like
necting device, a special time/time interval can be as- t lers ^ drive electronics can consequently be
signed for the communications between the higher- 10 , f . , . . ... , , ,
t i v c ^ J J.-L. ^ j • placed outside the electronics in the node/the module
level unit of the system and the connecting device pro- r T , ^ , x,. „ . , ,
TM J.- J unit. In order to do this, a T-coupler/connectine device
cessors. The connecting device processors can more- , , , , ,
over transmit emergency stop signals, which increases 18 ^duced, which links the node and the commumca
the possibilities for the system as such. It is possible to tl0n hne- In such a manner, two standardised barriers
construct simple interfaces and the CAN structure can 15 can be obtained, one for the interface between the node
likewise be preserved intact. Mechanical switches and ^the T-coupler and one for the interface between the
binary code arrangements can be eliminated in connect- T-coupler and the communication line. It is also possi
ing devices. A memory member can be used in connect- ble to handle fast signals for synchronisation. The fast
ing devices which can contain further information, for signals can be assigned to a separate bus connection,
example information on how the bus connection looks, 20 This also makes it possible to have separate bus connec
different variables/parameters which apply to the bus tions for different types of equipment and at the same
connection, the current degree of interference sensitiv- time that the machine in question can be synchronised
ity, the length of the bus connection and so forth. by means of this common synchronisation communica
LIST OF FIGURES t'on' *n on*er *^at ^e connected n°de know its place in
25 the CAN communication, there should be information
An embodiment of an arrangement which shows the about its place in the system. In order to obtain full or characteristics which are significant for the invention is g00(j flexibility, there should also be information on described below with simultaneous reference to the how the transmission of bits is to take place. According attached drawings, in which: to &e invention, it can be specified how this informa
FIG. 1 shows in block diagram form a computer 30 tion is transferred to the node on connection to the system with master units and slave umts connectedvia communication line/bus connection. According to a bus connection and connecting devices (T-boxes), FIQS ^ a 9 m DSUB connector ^ sockets is to
FIG. 2 shows m diagrammatic form a wiring diagram fee for tQ ^ T-coupler/connecting
for a connecting device to a module unit, , T ... .. , . r . ,
_,T/_, ^j-r ^ c-.c device. In this connecting device, the pins have the
FIG. 3 shows a connecting device for connection of 35 . . e v
the master unit, which connecting device includes a g n.
power supply for the bus connection,
FIG. 4 shows in diagrammatic form a connecting Pul Function
device with built-in microprocessor instead of a mem- : „, , ,—~.—; :—:—~~Z
, j. TM„„ < j ,n 1 +5 Volts for driving electronics in the T
ory member according to FIGS. 1-3, and 40 coupler> ^ +150 ^
FIG. 5 shows in perspective the connection of a mod- 2 GND for + 5 Volts, on pin l.
ule unit to machinery and to a connecting device for 3 CANout, transmission on the CAN bus, high when connection to the bus connection. recessive.
An arrangement implementing the invention can be 4 CANin' «cePti°n from the CAN bus, high when
based on a hardware connection with a 9-pin DSUB 45 s gYNCout, transmission on the CAN bus for connector. Via this connector, signals are transmitted synchronisation, high when recessive,
for a CAN bus, a synchronisation bus, an emergency 6 SYNCin, reception from the CAN bus for synchrostop bus, a serial input of address and bus data, as well nisation, high when recessive,
as power supply to external electronics. The signals can 7 EMERGENCYout, a signal for driving the emer
be held at TTT level and a nower <ainr.lv is effected 50 genoy stop Une'low on emer8ency stoP
oe aeia at 11 Ljevei ana a power supply is enectea g cODEdata, serial data, with address and mode
with + 5 Volts. The signals are transmitted to a T-cou- for speciflcatjon on interpreting data
pier which can contain electrical isolation of different see section 4.2.
types as well as drive electronics for driving signals On 9 EMERGENCYin, a signal which reflects the level
the communication line. How the communication line is on emergency stop bus, low on emergency
constructed depends upon which requirements are 55 stop Preset of the modme this used for
r . c. ,. i clocking m data on the line CODEdata.
made of the communication lme m terms of electrical
isolation, voltage levels, type of line, transmission
lengths and transmission rate. Although this part can Signals are to follow the TTL standard on signal levels
have a different structure in different systems, an exem- except on pins 8 and 9 which have the following data, plary embodiment according to the following is pro- 60
posed. In the computer system (the CAN system), com- '■
munication circuits of the type INTEL 82526 and ! XlTM < y.oits, vhigh > 3.85 Volts.
. , , . 9 Vlow < 1.35 Volts, Vhigh > 3.85 Volts.
82C200 (Philips) can be used. Other components can
nevertheless be used in this connection. It is also possible to group different functions in separate loops with 65 The information in question is entered into a memory
CAN communication, retaining the possibility of syn- circuit of the type X24C01 from XICOR or equivalent,
chronising the entire system with another CAN com- As a proposal, the following information can be in
munication. The system builder can use a solution with eluded in said memory circuit/memory member.