WO1989006839A1 - Interchangeable diagnostic instrument system - Google Patents

Interchangeable diagnostic instrument system Download PDF

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Publication number
WO1989006839A1
WO1989006839A1 PCT/US1989/000042 US8900042W WO8906839A1 WO 1989006839 A1 WO1989006839 A1 WO 1989006839A1 US 8900042 W US8900042 W US 8900042W WO 8906839 A1 WO8906839 A1 WO 8906839A1
Authority
WO
WIPO (PCT)
Prior art keywords
cartridge
control station
interchangeable
data
diagnostic instrument
Prior art date
Application number
PCT/US1989/000042
Other languages
French (fr)
Inventor
James E. Krass, Jr.
James F. Neely
Michael F. Kapolka
Original Assignee
Micro Processor Systems, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Micro Processor Systems, Inc. filed Critical Micro Processor Systems, Inc.
Publication of WO1989006839A1 publication Critical patent/WO1989006839A1/en

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02BINTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B77/00Component parts, details or accessories, not otherwise provided for
    • F02B77/08Safety, indicating or supervising devices
    • F02B77/083Safety, indicating or supervising devices relating to maintenance, e.g. diagnostic device
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/005Testing of electric installations on transport means
    • G01R31/006Testing of electric installations on transport means on road vehicles, e.g. automobiles or trucks
    • G01R31/007Testing of electric installations on transport means on road vehicles, e.g. automobiles or trucks using microprocessors or computers
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/28Testing of electronic circuits, e.g. by signal tracer
    • G01R31/317Testing of digital circuits
    • G01R31/3181Functional testing
    • G01R31/319Tester hardware, i.e. output processing circuits
    • G01R31/31903Tester hardware, i.e. output processing circuits tester configuration
    • G01R31/31915In-circuit Testers
    • GPHYSICS
    • G07CHECKING-DEVICES
    • G07CTIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
    • G07C5/00Registering or indicating the working of vehicles
    • G07C5/08Registering or indicating performance data other than driving, working, idle, or waiting time, with or without registering driving, working, idle or waiting time
    • G07C5/0808Diagnosing performance data

Definitions

  • the present invention relates generally to vehicular diagnostic systems and particularly to an interchangeable diagnostic instrument system which includes a portable communications control station and at least one removable data accessing cartridge.
  • the vehicle computer In order for the vehicle computer to properly perform its control functions, it typically interrogates a variety of sensors which are used to monitor various vehicle operation parameters. In several of these vehicle computer systems, as many as twenty or more sensors are employed for control purposes and to assist on-board diagnosis by the vehicle computer.
  • an Assembly Line Diagnostic Link (ALDL) terminal is installed under the dashboard of the vehicle in the passenger compartment.
  • This ALDL terminal is connected to an input/output (10) port of the vehicle computer or to an electronic control module (ECM) , to permit the transmission of monitored parameter data to the ALDL terminal upon reception of the appropriate data enable signal at the ALDL terminal.
  • ECM electronice control module
  • the above-identified Diagnostic Data Recorder (“DDR”) patent also describes another tool for obtaining vehicle data. Specifically, the DDR was designed to provide a portable communications control station which could transmit either live or recorded vehicle data via a telephone link to a remote data processing computer. Thus, for example, the DDR enabled data from on the road testing to be recorded for subsequent transmission to a remote computer which was capable of diagnosing difficult problems.
  • DDR Diagnostic Data Recorder
  • the present invention provides an interchangeable diagnostic system which generally comprises a universal communications control system and at least one removable data accessing cartridge for enabling the control station to process data from a plurality of disparate on-board vehicle computers.
  • the control station includes a portable housing, a keypad for permitting an operator to direct a diagnostic test procedure, a matrix display for selectively displaying data received from the on-board vehicle computer, and a microcomputer circuit for executing the diagnostic test procedure.
  • the removable cartridge includes a housing adapted to be connected to the control station housing, an interface circuit for causing the on-board vehicle computer to transmit a stream of data and for receiving this stream of data, and a read only memory for storing a computer program which controls, at least in part, the accessing of data from the on-board vehicle computer.
  • the control station includes a first terminal for communicating with the on-board vehicle computer, a second terminal for communicating with the removable cartridge, and a bus network for transmitting signals received from the on-board vehicle computer at the first terminal directly to the second terminal.
  • This direct transmission to the cartridge by initially bypassing the control station circuit is due to the fact that the design of the cartridge interface circuit is tailored to meet the needs of the particular vehicle being tested. In other words, the cartridge provides the mechanism which will enable the control station to process the data received from the particular vehicle being tested.
  • the control station does not have to be concerned with how the data is accessed from any particular vehicle model or make, as the specific circuits and control program required to access data from a particular vehicle manufacturer are all provided in the removable cartridge.
  • the removable cartridge may also be provided with additional circuits, such as a random access memory for storing a plurality of data streams from the on-board vehicle computer.
  • the random access memory is provided with an electrical power storage device, such as a capacitor, which will enable the random access memory to retain the data stored for at least several hours after the cartridge has been removed from the control station.
  • control station is designed such that one of the interchangeable cartridges needs to be connected to the control station in order for the control station to be operational.
  • the electrical power received at the first terminal of the control station is fed directly to the second terminal, without being used to provide electrical power to the circuit components in the control station.
  • the cartridge needs to be coupled to the control station in order for the electrical power supplied directly to the cartridge to be transmitted back to the control station in order for the circuits contained in the control station to be provided with the electrical power needed to operate the control station.
  • the control station is also preferably provided with a backlit liquid crystal display (LCD) , and the contrast circuitry needed to adjust the viewing angle of the LCD display.
  • the contrast circuitry is designed to operate under software control, so as to permit adjustments in the viewing angle to be made through a manual actuation of selected keys on the control station's keypad.
  • Figure 1 is a perspective view of an interchangeable diagnostic instrument system according to the present invention.
  • Figure 2 is a side elevation view of the universal communications control station connected to the removable cartridge of Figure 1.
  • Figures 3 -3C comprise the schematic diagrams for the circuits contained in the control station of Figure 1.
  • Figures " 4A-4C comprise the schematic diagrams for the cartridge used in diagnosing General Motors manufactured vehicles.
  • Figures 5A-5B comprise the schematic diagrams for the circuits contained in the cartridge used to diagnose Chrysler manufactured vehicles.
  • Figures 6A-6B comprise the schematic diagrams for the circuits contained in the cartridge used to diagnose Ford manufactured vehicles.
  • the diagnostic instrument system 10 generally comprises a universal communications control station 12 and a removable cartridge 14.
  • the control station 12 is referred to as being universal, because its use is not limited to diagnosing vehicles of any particular manufacturer, model year or model type.
  • the control station 12 is designed to be used with a plurality of interchangeable cartridges 14 which each enable the system to access data from predetermined on-board vehicle computers.
  • different cartridges are provided for General Motors manufactured vehicles, Chrysler manufactured vehicles and Ford manufactured vehicles.
  • Figure 1 also illustrates a cable assembly 16 which facilitates communication between the system 10 and the on-board vehicle being tested.
  • the cable system 16 also enables the system 10 to receive electrical power from the vehicle.
  • the cable assembly 16 includes a plug 18 which is adapted to be inserted into the cigarette lighter receptacle of the vehicle in order to transmit electrical power (12 volts D.C.) to the system 10.
  • the cable assembly 16 also includes a main connector 20 which combines the electrical power lines from the plug 18 with the data and control lines from an ALDL plug 22.
  • the cable assembly 16 may also be provided with one or more adaptors 24 which are designed for particular model years and types.
  • the adaptor 24 permits a common or standard design to be used for the ALDL plug 22, which will not be specific to any particular vehicle model or make.
  • the main connector 20 includes a fifteen pin terminal 26 which is adapted to be mated to a corresponding fifteen pin terminal mounted to the portable housing 28 of the control station 12. As shown in Figure 2, the fifteen pin terminal 30 of the control station 12 extends from a top side or end of the control station. However, it should be appreciated that in the appropriate application, the terminal 30 could also be mounted to the cartridge 14.
  • the main connector 20 may be removably mounted to the control station 12 via a pair of thumb screws on either side of the terminal 26.
  • the plug 18 may be provided with a suitable fuse (e.g., 2 amps) for protecting the system from electrical power surges.
  • the cartridge 14 is connected to the back of the control station 12 such that the cartridge extends along the same plane as a rear surface 32 of the control station.
  • the cartridge 14 is contained generally within the perimeter of outline of the housing 28 of the control station 12 when the cartridge is engaged with the control station.
  • the sides and ends of the housing 34 for the cartridge 14 are essentially coterminous with the sides and ends of the housing 28 for the control station 12. While this relationship may be modified in the appropriate application, it should be appreciated that the housing 28 for the control station 12 has a generally "L" shaped appearance from a side view, and that when the cartridge is engaged with the control station, the system 10 is provided with a boxlike appearance.
  • the cartridge 14 fills the rectangular shaped void space created by the design of the portable housing 28 for the control station. It should also be noted that the cartridge 14 is provided with a substantial depth which is sufficient to enable the cartridge to contain two circuit boards extending generally in parallel with each other. While the circuits to be described below for the cartridge 14 can all be contained on a single circuit board, the significant width of the cartridge housing 34 will enable substantial modifications to be made in the cartridge circuitry without affecting the appearance or design of either the cartridge or control station housings.
  • the cartridge 14 extends along a substantial length of the housing 28 for the control station 12.
  • the housing 34 of the cartridge 14 is also formed to provide a generally rectangular shaped cavity 36 along the interior facing side thereof.
  • the cavity 36 is formed in one embodiment according to the present invention by providing sidewalls which extend above a cover plate 38.
  • the cover plate 38 may be mounted to the housing 34 by a plurality of screws for protecting the circuit board enclosed within the housing. As shown in Figure 1, an edge connector 40 of this circuit board extends beyond the cover plate 38 to permit the cartridge
  • the housing 34 of the cartridge 14 is also provided with a pair of retention latches 42 which are disposed in the cavity 36 generally at the bottom end of the cartridge.
  • the retention latches 42 have two generally perpendicular ridges which are adapted to matingly engage a complementary shaped pair of grooves 44 formed in the housing 28 of the control station 12. One of these ridges extends parallel to the direction which the cartridge must be slid in order to connect the cartridge to the control station.
  • the grooves 44 are formed in a recessed ledge portion 46 of the control station housing 28 which extends around the periphery of the rearward side of the control station.
  • retention latches 42, grooves 44, recessed ledge portion 46 and cartridge cavity 36 all act together to automatically align the cartridge 14 with the control station 12 as it is slid into engagement with the control station. It should also be noted that retention latches are not necessary near the top end of the cartridge 14 as the edge connector 40 provides solid engagement with the control station 12 at this end.
  • the operator preferably places his or her thumbs on an inclined surface 47 of the control station housing 28, while using the other fingers to slide the cartridge away from the control station.
  • Figure 1 also shows that the control station 12 is provided with a keypad 48 which features sixteen keys.
  • the keypad 48 includes a set of ten numeric keys, four arrow keys, a function key (“FUNC”) , and an enter key (“ENTER”) .
  • the keypad 48 may be manually actuated by the operator to permit the operator to direct a desired diagnostic test procedure.
  • the function key is used to chose between various modes or jobs programmed into the system 10. Some of these functions relate to how the system 10 is operated, such as adjusting the contrast of a display 50 or transmitting data out to a serial communications jack 52.
  • the enter key of the keypad 48 may be used by the operator to make a selection, confirm an answer, or instruct the system to continue on to the next step in the diagnostic test procedure.
  • the up and down arrow keys are typically used to scroll through lines of the display 50, while the left and right arrow keys are typically used to toggle back and forth between choices given to the operator by the display.
  • the display 50 is preferably a backlit four lines by twenty character liquid crystal display (LCD) .
  • Such a display will permit several 5 vehicle data parameters to be displayed at one time to the operator, as well as permit various menus to be displayed for minimizing or eliminating the need for the operator to refer to any manuals for the system. As will be appreciated from the description below, the control
  • 10 station 12 is designed to enable the operator to adjust the contrast for viewing angle of the LCD display 50 by selecting the contrast adjust function and actuating the up or down arrow keys as desired.
  • control station As illustrated in Figure 2, the control station
  • a pushbutton 54 whose function may be varied depending upon the cartridge selected for the control station. For example, when the cartridge for General Motors vehicles is selected, the pushbutton 54 will control the operation of the air management system on
  • FIG. 5 a schematic diagram of a microcomputer based circuit 56 for the control station 12 is shown.
  • the circuit 56 includes a first terminal 58 for enabling the system 10 to communicate with the on-board vehicle computer, and a second terminal 60 0 for enabling the control station 12 to communicate with one of the cartridges 14.
  • the first terminal 58 generally comprises the fifteen pin terminal 30 which extends from the housing 28 of the control station 12, while the second terminal 60 generally comprises a multiple pin edge 5 connector for receiving the edge connector 40 of the cartridge 14.
  • One of the advantages of the present invention is that the system 10 is designed to prevent the control station 12 from operating without one of the cartridges 14 being properly engaged to the control station 12.
  • electrical power received at the first terminal 58 (12 volts D.C. across pins DA6 and DA11) is transmitted directly to the second terminal 60 via a bus structure 62 without first providing any electrical power to the circuits contained in the control station 12.
  • the pins labeled DA6 and DA11 of the second terminal 60 indicate that the electrical power received at the first terminal 58 is first transmitted to the cartridge 14.
  • the pin labeled "+12V Diode" at the bottom of the second terminal 60 indicates that the cartridge 14 retransmits this electrical power back to the control station for conditioning in a switching power supply circuit 62.
  • the switching power supply circuit 62 is used to generate a +5 volts D.C. supply from the 12 volts D.C. power received from the vehicle.
  • the switching power supply circuit 62 features a regulator 64 which produces a pulse output whose frequency will determine the voltage produced at the output of the switching power supply circuit.
  • a choke coil 66 and a capacitor 68 are used in the switching power supply circuit 62 to store energy during the off periods of the pulse output from the regulator 64 in order to present a substantially constant 5 volt voltage level at the output of the switching power supply circuit 62.
  • the switching power supply circuit 62 may also include a low voltage cutoff circuit 70 which will prevent the circuits contained in the system 10 from operating when the voltage received from the vehicle drops below a predetermined threshold level.
  • the 5 volt output from the power supply circuit 62 is connected to the second terminal 60 in order to transmit a power supply level which is usable by the circuits contained in the cartridge 14.
  • the circuit 56 features a Hitachi microcomputer chip 72 which acts as a central controller for the system 10. However, it should be appreciated that other single chip or multiple chip CPU or computer circuits may be used in the appropriate application.
  • Figure 3B indicates that the microcomputer chip 72 is connected to the keypad 48 such that the depressing of any of the individual keys will cause a high input signal (e.g. 5 volts) to be applied to predetermined pairs of the input pins P60-P67.
  • An inverter may also be connected to each of the pins P64-P67 between the keypad 48 and a pull-up resistor (SIP5) in order to enable a keyboard interrupt line "KIRQ" to switch to a HIGH state whenever one of the keys are depressed.
  • SIP5 pull-up resistor
  • a similar connection may also be provided for the pushbutton 54, which is connected to pin P57.
  • Figure 3A shows that the circuit 56 also includes a programmable logic array circuit 74.
  • the programmable logic array circuit 74 is connected to the bus structure 62, and functions as an address decoder for the microcomputer chip 72.
  • the programmable logic array circuit 74 includes a plurality of logic gates which are programmably connected to enable this circuit to generate an appropriate chip select signal in response to an address command from the microcomputer chip via address lines A9-A15 of the bus network.
  • the programmable logic array circuit 74 includes a chip select output port labeled "DISP" which is used to enable the display 50 to receive data or information signals from the microcomputer chip 72.
  • a D.C. to A.C. inverter circuit 76 is connected to the display 50 to provide the 80-100 volt supply necessary to backlight the LCD display.
  • the circuit 56 is shown to include a dual universal asynchronous receiver transmitter (“DUART") chip 78 which is also connected to the bus structure 62.
  • the DUART chip 78 includes two UART circuits which may be accessed by the microcomputer chip 72.
  • One of the UART circuits in the DUART chip 78 is used to permit serial communication with an external device such as a test computer or a printer. This serial communication is provided via the modular phone jack 52.
  • a converter circuit 80 e.g. Maxim 232CPE
  • Communication between the microcomputer 72 and an external device are provided via the signal lines labeled "REC1" and "XMIT1". While the second UART available on the DUART chip 78 is not currently used in the circuit, this added capability for an additional serial communication channel lends substantial flexibility to the circuit 56 for future applications. For example, the communication lines for the second UART (labeled “REC2" and “XMIT2”) are transmitted to the second terminal 60 via the bus structure 62 to permit this second communication channel to be used with future cartridges requiring such an additional serial communications channel.
  • the DUART chip 78 converts serial information to parallel information for transmission to or reception from the microcomputer chip 72 via its data lines DO-D7 which form part of the bus structure 62.
  • the DUART chip 78 also includes a timer circuit which produces a pulse signal at pin labeled "OP3" in response to a command signal from the microcomputer chip which is written to an internal register of the DUART chip.
  • This pulse signal is used in a contrast circuit 82 for adjusting the viewing angle of the LCD display 50.
  • the contrast circuit 82 operates as a frequency to voltage converter which will produce a voltage level on output line 84 which is proportionally related to the frequency of the pulse signal.
  • the pulse signal on input line 86 is used to change the output states of a comparator 88 and FET transistor 90.
  • the input line 86 is tied to a 5 volt supply through a pull-up resistor 92 which will provide a fixed HIGH voltage level when a pulse is transmitted on input line 86.
  • Resistors 94 and 96 provide a resistor divider network which produces a 2.5 volt reference level for the comparator 88.
  • FIG. 4A-4C a schematic diagram of the cartridge circuit 110 for the cartridge used to diagnose General Motors vehicles is shown. This particular cartridge circuit 110 is applicable for General Motors model years 1980 ⁇ through 1988.
  • the cartridge circuit 110 includes the edge connector 40 for permitting communication between the cartridge and the control station 12.
  • the edge connector 40 shown on Figure 4A is also continued on Figure 4B, and comprises one and the same edge connector.
  • the cartridge circuit 110 also includes an interface circuit generally designated by the reference numeral 112 for causing the on-board vehicle computer to transmit a stream of data and for receiving this data for subsequent transmission to the microcomputer chip 72.
  • the interface circuit 112 includes a diagnostic enable line 114 which can be controlled in several different ways. Specifically, command signals generated at the microcomputer chip 72 will be transmitted to a versatile interface adapter circuit 116 (e.g. Rockwell 6522) via the cartridge bus structure 118 to vary the signal on the diagnostic enable line 114 in accordance with the diagnostic procedure desired by the operator.
  • a versatile interface adapter circuit 116 e.g. Rockwell 6522
  • the interface circuit 112 provides a "special mode" diagnostic enable line connected to pin PB4 of the VIA circuit 116 for directing the on-board vehicle computer to enter the special mode of operation.
  • the special mode of operation is one used at the end of the assembly line to check systems before the vehicle is shipped. Selecting this special mode will cause certain engine functions to behave differently than they otherwise would.
  • the special mode diagnostic line is connected to the diagnostic enable line 114 through an inverter 120 and a resistor 122 which will cause the amplitude of the voltage of the diagnostic enable line to change.
  • the interface circuit 112 includes similar diagnostic mode selection lines for the "back-up mode" and "ground mode" enable features of various on-board vehicle computers.
  • the interface circuit 112 includes several conductors which can receive data from the on-board vehicle computer.
  • the conductor labeled "CLCC data” is used to receive data from carbureted vehicles
  • the conductor labeled “EFI data” is used to receive data from vehicles with fuel injection systems.
  • the EFI data conductor is also connected to a serial in/out conductor 124 which operates as a high speed communication line to and from the on-board vehicle computer. This reflects the fact that in some on-board vehicle computers the EFI data is transmitted at high speeds (8192 baud or 9600 baud) .
  • the interface circuit 112 also includes another conductor labeled "TCC solenoid" for receiving an indication when torque converter clutch lock-up command is given by th on-board vehicle computer.
  • Each of the above dat reception conductors is connected to a buffered amplifie circuit such as buffered amplifier circuit 126 for the CLCC data conductor.
  • a gating logic circuit 128 is also connected to the outputs of the buffered amplifier circuits for the CLCC data and EFI data conductors to permit the microcomputer chip 72 to select which of these two low speed data lines will be transmitting data to the microcomputer chip via "ALDL" data line 130.
  • the interface circuit 112 also includes a relay circuit 132 for causing a 5 volt pull-up signal to be transmitted to the on-board vehicle computer.
  • a similar relay circuit 134 is used to operate the air control solenoid in the air management system of the vehicle.
  • Each of these relay circuits includes a transistor which will close a relay when gated on by an appropriate command signal transmitted through the VIA chip 116 from the microcomputer chip 72.
  • the cartridge circuit 110 includes a diode 136 which operates to protect the system 10 from any negative voltage being supplied from the vehicle. It may also be noted that the cartridge circuit 110 includes a number of metal oxide varistors ("MOV”), such as MOV 138. These metal oxide varistors are adapted to provide a lower resistance to higher voltage levels to protect the circuit from abnormal voltage surges.
  • MOV metal oxide varistors
  • FIG 4B the cartridge circuit 110 is shown to be provided with three memory circuits 140-144.
  • the memory circuits 140-142 are each 32K by eight-bit EPROM chips, which operate as read only memories for storing a computer program which controls, at least in part, the accessing of data from the on-board vehicle computer.
  • these memory chips 140-142 store the program which is used by the microcomputer chip 72 to appropriately communicate with the particular vehicles for which the cartridges are designed to be used for. While it may not presently be necessary for the cartridge to be provided with two separate 32 memory chips, they have been provided in this particular embodiment in order to provide added flexibility for future years when such additional memory space may eventually be required. Thus, for example, if only one of these memory chips is desired to be placed in the cartridge, appropriate jumpers 146 and 148 have been provided to readily alter the address requirements for these chips.
  • the memory chip 144 is preferably an 8 by eight-bit random access memory ("RAM") which can be used for storing a plurality of data streams received from the on-board vehicle computer.
  • RAM random access memory
  • the interface circuit 112 transmits the data received from the on-board vehicle computer first to the microcomputer chip 72, which then subsequently transmits this data back to the memory chip 144 for storage in a circular file which will permit the operator to scroll through a set of predetermined data parameters.
  • the memory chip 144 is also used to permit the microcomputer chip 72 to preprocess the data being received from the on-board vehicle computer by verifying and checking these data streams.
  • the cartridge circuit 110 also features an electrical power storage device for enabling the memory circuit 144 to retain its stored data streams when electrical power is disconnected from the cartridge, such as when the cartridge is removed from the control station 12.
  • this electrical power storage device comprises a large capacitor, such as the one farad capacitor 150 which is connected to the voltage input port of the memory chip 144.
  • a diode 152 is connected between the 5 volt supply and the capacitor 150 to prevent the capacitor from being discharged into the 5 volt supply. While a battery could be used instead of the capacitor 150, the capacitor has the advantage of never having to be replaced as in the case of a battery.
  • the cartridge circuit 110 also includes a reset circuit 154 which generates a reset signal on conductor 156 when power is first supplied to the cartridge.
  • the reset circuit 154 includes a capacitor 158 and a resistor 160 which combine to provide a time delay between the time that the power is first applied and the transistor 162 is gated on to provide the reset signal.
  • the reset signal on line 156 is used to reset all of the chips in the cartridge as well as all of the chips in the control station which require resetting at start-up.
  • Figure 4B also indicates that the interface circuit 112 is provided with a high speed transmission circuit 164 for transmitting and receiving high speed data signals on conductor 124.
  • a FET transistor 166 is provided in the transmission circuit 164 for switching the conductor 124 between an open state and a zero volt state.
  • An inverter 168 is used to protect the FET transistor 166 from excessive dry currents or logic inversions.
  • a pair of inverters 170-172 are used in the receiver line to act as a buffer which will protect the UART circuit contained in the microcomputer chip 72.
  • the cartridge circuit 110 is shown to include an oscillator circuit 174 which is adapted to generate a 8192 baud rate signal on conductor 176.
  • the oscillator circuit 174 includes a 4.19304 megahertz crystal and a pair of ripple counters 178 and 180 which provide divide by four and divide eight functions respectively.
  • the cartridge circuit 110 is capable of providing for one or more oscillator circuits which will enable or facilitate high speed data and other signal communications with the on-board vehicle computer.
  • FIGs 5A and 5B a schematic diagram of a cartridge circuit 182 for diagnosing Chrysler manufactured vehicles is shown. For convenience, similar components to those described in connection with Figures 4A and 4B are primed in Figures 5A and 5B.
  • a substantially simplified interface circuit 184 is provided.
  • the interface circuit 184 includes a diagnostic enable or "read-hold" line 186 for transmitting a signal to the on-board vehicle computer which will cause the computer to transmit data to the system via data line 188.
  • the VIA chip 116' is bypassed in order to transmit data directly to the microcomputer chip 72 contained in the control station 12.
  • the interface circuit 184 also includes a relay circuit 190 for transmitting an actuator signal to the on-board vehicle computer under software control.
  • Figure 5A also shows that the cartridge circuit 182 may include an oscillator circuit 192 for generating 976 baud and 7812 baud clock signals.
  • the cartridge circuit 194 for diagnosing Ford manufactured vehicles is shown.
  • the cartridge circuit 194 includes an interface circuit generally designated by the reference numeral 196.
  • the interface circuit includes a relay circuit 198 for closing a relay which will cause a "latch" signal to be transmitted to the on-board vehicle computer for causing the on-board vehicle computer to transmit data to the system.
  • the interface circuit 196 also includes a buffered amplifier circuit 126" for receiving data transmitted from the on-board vehicle computer.
  • the interface circuit 196 further includes a "SONALERT" circuit 200 for causing a chirping or beeping sound to emanate from a sonalert device 202 during the transmission of data from the on-board vehicle computer to the system 10.
  • the microcomputer chip 72 will transmit a sonalert command through the VIA circuit 116" to a NAND gate 204.
  • the output state of the NAND gate 204 will be toggled HIGH and LOW in response to the gating on and off of the transistor contained in the buffered amplifie circuit 126".
  • the entire computer program for operating the system 10 can be stored in the EPROM circuits 140-142, it should be appreciated that the microcomputer chip 72 or other appropriate microcomputer circuit may additionally be provided with read only memory for storing common portions of the program needed to enable the control station to operate.

Abstract

An interchangeable diagnostic system (10) is disclosed which comprises a universal communications control station (12) and at least one removable data accessing cartridge (14) for enabling the same control station (12) to process data from a plurality of disparate on-board vehicle computers. The control station (12) includes a portable housing (28), a keypad (48) for permitting an operator to direct a diagnostic test procedure, a matrix display (50) for selectively displaying data received from the on-board vehicle computer, and a microcomputer circuit (56) for executing the diagnostic test procedure. The removable cartridge includes a housing (34) adapted to be connected to the control station housing (28), an interface circuit (112) for causing the on-board vehicle computer to transmit a stream of data and for receiving this stream of data, and a read only memory (140-142) for storing a computer program which controls, at least in part, the accessing of data from the on-board vehicle computer.

Description

INTERCHANGEABLE DIAGNOSTIC INSTRUMENT SYSTEM
TECHNICAL FIELD
The present invention relates generally to vehicular diagnostic systems and particularly to an interchangeable diagnostic instrument system which includes a portable communications control station and at least one removable data accessing cartridge.
With the advent of motor vehicles being equipped with computer control systems by the manufacturer, the repair of malfunctions has become substantially more sophisticated than in the past. In order for the vehicle computer to properly perform its control functions, it typically interrogates a variety of sensors which are used to monitor various vehicle operation parameters. In several of these vehicle computer systems, as many as twenty or more sensors are employed for control purposes and to assist on-board diagnosis by the vehicle computer.
In many vehicle models, there is provided a means for obtaining direct access to the monitored parameter data, on a real time basis, so that various display tools, engine analyzers and so forth may be used to facilitate a more complete diagnosis than that provided by the on-board vehicle computer. For example, in many General Motors vehicle models, an Assembly Line Diagnostic Link (ALDL) terminal is installed under the dashboard of the vehicle in the passenger compartment. This ALDL terminal is connected to an input/output (10) port of the vehicle computer or to an electronic control module (ECM) , to permit the transmission of monitored parameter data to the ALDL terminal upon reception of the appropriate data enable signal at the ALDL terminal.
A variety of devices have been developed over the years for the purpose of tapping into the data which is accessible from these on-board vehicle computers. In this regard, some of the earliest devices were hand held display tools, such as the "Mini-Scanner" and "Multi-Scanner" models marketed by the assignee of the present invention, Micro Processor Systems, Inc. These MPSI tools were designed to display the value or status of individual parameters in response to the manual actuation of a slide or rotary switch. An example of such a tool is shown in Figure 2 of the Neely and Krass U.S. Patent No. 4,602,127, which issued on July 22, 1986, and is entitled "Diagnostic Data Recorder". This patent is hereby incorporated by reference.
The above-identified Diagnostic Data Recorder ("DDR") patent also describes another tool for obtaining vehicle data. Specifically, the DDR was designed to provide a portable communications control station which could transmit either live or recorded vehicle data via a telephone link to a remote data processing computer. Thus, for example, the DDR enabled data from on the road testing to be recorded for subsequent transmission to a remote computer which was capable of diagnosing difficult problems.
More recently, a communications adapter circuit board has been developed which is capable of being plugged directly into the bus structure of a generalized test computer to enable rapid signal transmissions between the on-board vehicle computer and the test computer. This communications adapter circuit is described in the commonly assigned co-pending patent application Serial No. 774,348, which was filed on September 10, 1985 and entitled "Vehicle Computer Diagnostic Interface Apparatus". This patent application is also hereby incorporated by reference.
While each of these products have been very effective and successful, the specific designs of these products have necessarily been related to particular vehicle manufacturers. Due in part to rapid developments in the field of on-board computer systems, data transmission rates and protocols typically vary from one vehicle manufacturer to another, and such variations can also be found for different vehicle model years and model types of the same manufacturer. Accordingly, separate tools have generally been marketed for the vehicles of each vehicle manufacturer by either modifying an existing tool or creating a new tool to fit the particular application.
These developments, of course, have presented a problem for those repair and maintenance facilities who service or would like to service vehicles produced by different manufacturers, because it creates a need to buy several types of tools in order to perform the work with the equipment which is appropriate for each vehicle make and model. This situation has also required manufacturers of diagnostic equipment to absorb additional redesign, inventory and related costs in order to offer a full and up-to-date line of vehicle diagnostic products.
DISCLOSURE OF INVENTION
Accordingly, it is a principle objective of the present invention to provide a universal diagnostic instrument system which can readily be used on a variety of different vehicle models and makes without having to be modified or redesigned.
More specifically, it is an objective of the present invention to provide a universal communications control station which is designed to operate with a plurality of interchangeable cartridges that will enable data to be accessed from different vehicle models and makes. It is another objective of the present invention to provide a data accessing cartridge design which will minimize or eliminate the need to update the universal communications control station for years to come.
It is an additional objective of the present invention to achieve a combined universal communications control station and data accessing cartridge system which will provide significant flexibility for aiding future cartridge designs.
It is a further objective of the present invention to enable the data accessing cartridge to store data and retain the stored data for a predetermined period of time after the cartridge has been removed from the control station.
It is yet another objective of the present invention to provide an interchangeable diagnostic system which requires the presence of the data accessing cartridge in order for the system to be operational.
It is yet a further objective of the present invention to provide a hand held interchangeable diagnostic instrument system which is not only capable of communicating with the vehicle, but also capable of communicating with test computers and peripheral devices, such as printers.
It is still another objective of the present invention to provide a universal communications control station which will enable contrast adjustments to be made in the display for the control station through software implementation.
To achieve the foregoing objectives, the present invention provides an interchangeable diagnostic system which generally comprises a universal communications control system and at least one removable data accessing cartridge for enabling the control station to process data from a plurality of disparate on-board vehicle computers.
The control station includes a portable housing, a keypad for permitting an operator to direct a diagnostic test procedure, a matrix display for selectively displaying data received from the on-board vehicle computer, and a microcomputer circuit for executing the diagnostic test procedure. The removable cartridge includes a housing adapted to be connected to the control station housing, an interface circuit for causing the on-board vehicle computer to transmit a stream of data and for receiving this stream of data, and a read only memory for storing a computer program which controls, at least in part, the accessing of data from the on-board vehicle computer.
In one form of the present invention, the control station includes a first terminal for communicating with the on-board vehicle computer, a second terminal for communicating with the removable cartridge, and a bus network for transmitting signals received from the on-board vehicle computer at the first terminal directly to the second terminal. This direct transmission to the cartridge by initially bypassing the control station circuit is due to the fact that the design of the cartridge interface circuit is tailored to meet the needs of the particular vehicle being tested. In other words, the cartridge provides the mechanism which will enable the control station to process the data received from the particular vehicle being tested. Thus, it should be appreciated that the control station does not have to be concerned with how the data is accessed from any particular vehicle model or make, as the specific circuits and control program required to access data from a particular vehicle manufacturer are all provided in the removable cartridge.
The removable cartridge may also be provided with additional circuits, such as a random access memory for storing a plurality of data streams from the on-board vehicle computer. In one form of the present invention, the random access memory is provided with an electrical power storage device, such as a capacitor, which will enable the random access memory to retain the data stored for at least several hours after the cartridge has been removed from the control station.
Another feature of the present invention, is that the control station is designed such that one of the interchangeable cartridges needs to be connected to the control station in order for the control station to be operational. Specifically, in one form of the present invention, the electrical power received at the first terminal of the control station is fed directly to the second terminal, without being used to provide electrical power to the circuit components in the control station. Thus, the cartridge needs to be coupled to the control station in order for the electrical power supplied directly to the cartridge to be transmitted back to the control station in order for the circuits contained in the control station to be provided with the electrical power needed to operate the control station.
The control station is also preferably provided with a backlit liquid crystal display (LCD) , and the contrast circuitry needed to adjust the viewing angle of the LCD display. In one form of the present invention, the contrast circuitry is designed to operate under software control, so as to permit adjustments in the viewing angle to be made through a manual actuation of selected keys on the control station's keypad.
Additional advantages and features of the present invention will become apparent from a reading of the detailed description of the preferred embodiment which makes reference to the following set of drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of an interchangeable diagnostic instrument system according to the present invention.
Figure 2 is a side elevation view of the universal communications control station connected to the removable cartridge of Figure 1. Figures 3 -3C comprise the schematic diagrams for the circuits contained in the control station of Figure 1.
Figures" 4A-4C comprise the schematic diagrams for the cartridge used in diagnosing General Motors manufactured vehicles. Figures 5A-5B comprise the schematic diagrams for the circuits contained in the cartridge used to diagnose Chrysler manufactured vehicles.
Figures 6A-6B comprise the schematic diagrams for the circuits contained in the cartridge used to diagnose Ford manufactured vehicles.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring to Figure 1, a perspective view of an interchangeable diagnostic instrument system 10 according to the present invention is shown. The diagnostic instrument system 10 generally comprises a universal communications control station 12 and a removable cartridge 14. The control station 12 is referred to as being universal, because its use is not limited to diagnosing vehicles of any particular manufacturer, model year or model type. In other words, the control station 12 is designed to be used with a plurality of interchangeable cartridges 14 which each enable the system to access data from predetermined on-board vehicle computers. Thus, for example, as will be appreciated from Figures 4 through 6, different cartridges are provided for General Motors manufactured vehicles, Chrysler manufactured vehicles and Ford manufactured vehicles.
Figure 1 also illustrates a cable assembly 16 which facilitates communication between the system 10 and the on-board vehicle being tested. The cable system 16 also enables the system 10 to receive electrical power from the vehicle. Specifically, the cable assembly 16 includes a plug 18 which is adapted to be inserted into the cigarette lighter receptacle of the vehicle in order to transmit electrical power (12 volts D.C.) to the system 10. The cable assembly 16 also includes a main connector 20 which combines the electrical power lines from the plug 18 with the data and control lines from an ALDL plug 22. The cable assembly 16 may also be provided with one or more adaptors 24 which are designed for particular model years and types. In other words, the adaptor 24 permits a common or standard design to be used for the ALDL plug 22, which will not be specific to any particular vehicle model or make. The main connector 20 includes a fifteen pin terminal 26 which is adapted to be mated to a corresponding fifteen pin terminal mounted to the portable housing 28 of the control station 12. As shown in Figure 2, the fifteen pin terminal 30 of the control station 12 extends from a top side or end of the control station. However, it should be appreciated that in the appropriate application, the terminal 30 could also be mounted to the cartridge 14. In one form of the present invention, the main connector 20 may be removably mounted to the control station 12 via a pair of thumb screws on either side of the terminal 26. It should also be noted that the plug 18 may be provided with a suitable fuse (e.g., 2 amps) for protecting the system from electrical power surges.
As shown in Figure 2, the cartridge 14 is connected to the back of the control station 12 such that the cartridge extends along the same plane as a rear surface 32 of the control station. Preferably, the cartridge 14 is contained generally within the perimeter of outline of the housing 28 of the control station 12 when the cartridge is engaged with the control station. Thus, for example, the sides and ends of the housing 34 for the cartridge 14 are essentially coterminous with the sides and ends of the housing 28 for the control station 12. While this relationship may be modified in the appropriate application, it should be appreciated that the housing 28 for the control station 12 has a generally "L" shaped appearance from a side view, and that when the cartridge is engaged with the control station, the system 10 is provided with a boxlike appearance. In other words, the cartridge 14 fills the rectangular shaped void space created by the design of the portable housing 28 for the control station. It should also be noted that the cartridge 14 is provided with a substantial depth which is sufficient to enable the cartridge to contain two circuit boards extending generally in parallel with each other. While the circuits to be described below for the cartridge 14 can all be contained on a single circuit board, the significant width of the cartridge housing 34 will enable substantial modifications to be made in the cartridge circuitry without affecting the appearance or design of either the cartridge or control station housings.
As shown in Figure 2, the cartridge 14 extends along a substantial length of the housing 28 for the control station 12. The housing 34 of the cartridge 14 is also formed to provide a generally rectangular shaped cavity 36 along the interior facing side thereof. The cavity 36 is formed in one embodiment according to the present invention by providing sidewalls which extend above a cover plate 38. The cover plate 38 may be mounted to the housing 34 by a plurality of screws for protecting the circuit board enclosed within the housing. As shown in Figure 1, an edge connector 40 of this circuit board extends beyond the cover plate 38 to permit the cartridge
14 to be electrically connected to the control station 12.
The housing 34 of the cartridge 14 is also provided with a pair of retention latches 42 which are disposed in the cavity 36 generally at the bottom end of the cartridge. The retention latches 42 have two generally perpendicular ridges which are adapted to matingly engage a complementary shaped pair of grooves 44 formed in the housing 28 of the control station 12. One of these ridges extends parallel to the direction which the cartridge must be slid in order to connect the cartridge to the control station. The grooves 44 are formed in a recessed ledge portion 46 of the control station housing 28 which extends around the periphery of the rearward side of the control station. This combination of retention latches 42, grooves 44, recessed ledge portion 46 and cartridge cavity 36 all act together to automatically align the cartridge 14 with the control station 12 as it is slid into engagement with the control station. It should also be noted that retention latches are not necessary near the top end of the cartridge 14 as the edge connector 40 provides solid engagement with the control station 12 at this end. To remove the cartridge 14 from the control station 12, the operator preferably places his or her thumbs on an inclined surface 47 of the control station housing 28, while using the other fingers to slide the cartridge away from the control station.
Figure 1 also shows that the control station 12 is provided with a keypad 48 which features sixteen keys. Specifically, the keypad 48 includes a set of ten numeric keys, four arrow keys, a function key ("FUNC") , and an enter key ("ENTER") . The keypad 48 may be manually actuated by the operator to permit the operator to direct a desired diagnostic test procedure. The function key is used to chose between various modes or jobs programmed into the system 10. Some of these functions relate to how the system 10 is operated, such as adjusting the contrast of a display 50 or transmitting data out to a serial communications jack 52. Other of these functions relate to the way in which the system communicates with the on-board vehicle computer, such as displaying live data from the vehicle, displaying trouble codes stored in the on-board vehicle computer, enabling predetermined diagnostic modes of the on-board vehicle computer, and controlling the data update rate. The enter key of the keypad 48 may be used by the operator to make a selection, confirm an answer, or instruct the system to continue on to the next step in the diagnostic test procedure. The up and down arrow keys are typically used to scroll through lines of the display 50, while the left and right arrow keys are typically used to toggle back and forth between choices given to the operator by the display. The display 50 is preferably a backlit four lines by twenty character liquid crystal display (LCD) . One example of such a display is the OPTRES model DMC20434E display. Such a display will permit several 5 vehicle data parameters to be displayed at one time to the operator, as well as permit various menus to be displayed for minimizing or eliminating the need for the operator to refer to any manuals for the system. As will be appreciated from the description below, the control
10 station 12 is designed to enable the operator to adjust the contrast for viewing angle of the LCD display 50 by selecting the contrast adjust function and actuating the up or down arrow keys as desired.
As illustrated in Figure 2, the control station
15 12 is also equipped with a pushbutton 54, whose function may be varied depending upon the cartridge selected for the control station. For example, when the cartridge for General Motors vehicles is selected, the pushbutton 54 will control the operation of the air management system on
20 the vehicle. In other words, each time the pushbutton is depressed by the operator, air will be immediately directed into the exhaust manifold ahead of the catalytic converter. Then, when the pushbutton is released the air flow will revert back to its normal operation. 5 Referring to Figures 3A-3C, a schematic diagram of a microcomputer based circuit 56 for the control station 12 is shown. The circuit 56 includes a first terminal 58 for enabling the system 10 to communicate with the on-board vehicle computer, and a second terminal 60 0 for enabling the control station 12 to communicate with one of the cartridges 14. The first terminal 58 generally comprises the fifteen pin terminal 30 which extends from the housing 28 of the control station 12, while the second terminal 60 generally comprises a multiple pin edge 5 connector for receiving the edge connector 40 of the cartridge 14. One of the advantages of the present invention is that the system 10 is designed to prevent the control station 12 from operating without one of the cartridges 14 being properly engaged to the control station 12. In this regard, electrical power received at the first terminal 58 (12 volts D.C. across pins DA6 and DA11) is transmitted directly to the second terminal 60 via a bus structure 62 without first providing any electrical power to the circuits contained in the control station 12. In this regard, the pins labeled DA6 and DA11 of the second terminal 60 indicate that the electrical power received at the first terminal 58 is first transmitted to the cartridge 14. The pin labeled "+12V Diode" at the bottom of the second terminal 60 indicates that the cartridge 14 retransmits this electrical power back to the control station for conditioning in a switching power supply circuit 62.
The switching power supply circuit 62 is used to generate a +5 volts D.C. supply from the 12 volts D.C. power received from the vehicle. The switching power supply circuit 62 features a regulator 64 which produces a pulse output whose frequency will determine the voltage produced at the output of the switching power supply circuit. A choke coil 66 and a capacitor 68 are used in the switching power supply circuit 62 to store energy during the off periods of the pulse output from the regulator 64 in order to present a substantially constant 5 volt voltage level at the output of the switching power supply circuit 62. The switching power supply circuit 62 may also include a low voltage cutoff circuit 70 which will prevent the circuits contained in the system 10 from operating when the voltage received from the vehicle drops below a predetermined threshold level. The 5 volt output from the power supply circuit 62 is connected to the second terminal 60 in order to transmit a power supply level which is usable by the circuits contained in the cartridge 14. The circuit 56 features a Hitachi microcomputer chip 72 which acts as a central controller for the system 10. However, it should be appreciated that other single chip or multiple chip CPU or computer circuits may be used in the appropriate application. Figure 3B indicates that the microcomputer chip 72 is connected to the keypad 48 such that the depressing of any of the individual keys will cause a high input signal (e.g. 5 volts) to be applied to predetermined pairs of the input pins P60-P67. An inverter may also be connected to each of the pins P64-P67 between the keypad 48 and a pull-up resistor (SIP5) in order to enable a keyboard interrupt line "KIRQ" to switch to a HIGH state whenever one of the keys are depressed. A similar connection may also be provided for the pushbutton 54, which is connected to pin P57.
Figure 3A shows that the circuit 56 also includes a programmable logic array circuit 74. The programmable logic array circuit 74 is connected to the bus structure 62, and functions as an address decoder for the microcomputer chip 72. The programmable logic array circuit 74 includes a plurality of logic gates which are programmably connected to enable this circuit to generate an appropriate chip select signal in response to an address command from the microcomputer chip via address lines A9-A15 of the bus network. Thus, for example, the programmable logic array circuit 74 includes a chip select output port labeled "DISP" which is used to enable the display 50 to receive data or information signals from the microcomputer chip 72. As shown in Figure 3B, a D.C. to A.C. inverter circuit 76 is connected to the display 50 to provide the 80-100 volt supply necessary to backlight the LCD display.
Referring to Figure 3C, the circuit 56 is shown to include a dual universal asynchronous receiver transmitter ("DUART") chip 78 which is also connected to the bus structure 62. The DUART chip 78 includes two UART circuits which may be accessed by the microcomputer chip 72. One of the UART circuits in the DUART chip 78 is used to permit serial communication with an external device such as a test computer or a printer. This serial communication is provided via the modular phone jack 52. A converter circuit 80 (e.g. Maxim 232CPE) is interposed between the DUART chip 78 and the phone jack 52 to convert the TTL 0-5 volt level signals from the DUART to RS 232 compatible +/- 12 volt signal levels.
Communication between the microcomputer 72 and an external device are provided via the signal lines labeled "REC1" and "XMIT1". While the second UART available on the DUART chip 78 is not currently used in the circuit, this added capability for an additional serial communication channel lends substantial flexibility to the circuit 56 for future applications. For example, the communication lines for the second UART (labeled "REC2" and "XMIT2") are transmitted to the second terminal 60 via the bus structure 62 to permit this second communication channel to be used with future cartridges requiring such an additional serial communications channel.
It should be appreciated from the above that the DUART chip 78 converts serial information to parallel information for transmission to or reception from the microcomputer chip 72 via its data lines DO-D7 which form part of the bus structure 62. The DUART chip 78 also includes a timer circuit which produces a pulse signal at pin labeled "OP3" in response to a command signal from the microcomputer chip which is written to an internal register of the DUART chip. This pulse signal is used in a contrast circuit 82 for adjusting the viewing angle of the LCD display 50. The contrast circuit 82 operates as a frequency to voltage converter which will produce a voltage level on output line 84 which is proportionally related to the frequency of the pulse signal. The pulse signal on input line 86 is used to change the output states of a comparator 88 and FET transistor 90. The input line 86 is tied to a 5 volt supply through a pull-up resistor 92 which will provide a fixed HIGH voltage level when a pulse is transmitted on input line 86. Resistors 94 and 96 provide a resistor divider network which produces a 2.5 volt reference level for the comparator 88. When a pulse is transmitted on input line 86, the output states of the comparator 88 and the FET 90 will permit a capacitor 100 to charge. Then, at the lagging edge of the pulse, the comparator 88 and the FET 90 will switch states and permit the capacitor 100 to discharge through a diode 102 to charge up a capacitor 104. The charge on the capacitor 104 will establish a voltage level on conductor 106 which is transmitted through a voltage follower circuit 108 to the output conductor 84. Accordingly, it will be appreciated that the frequency of the pulse signal on input conductor 86 will control the charge on the capacitor 104 by permitting a transfer of the charge on the capacitor 100 to be transferred or leaked to the capacitor 104. Referring to Figures 4A-4C, a schematic diagram of the cartridge circuit 110 for the cartridge used to diagnose General Motors vehicles is shown. This particular cartridge circuit 110 is applicable for General Motors model years 1980} through 1988. The cartridge circuit 110 includes the edge connector 40 for permitting communication between the cartridge and the control station 12. The edge connector 40 shown on Figure 4A is also continued on Figure 4B, and comprises one and the same edge connector. The cartridge circuit 110 also includes an interface circuit generally designated by the reference numeral 112 for causing the on-board vehicle computer to transmit a stream of data and for receiving this data for subsequent transmission to the microcomputer chip 72. As will be appreciated from comparing Figure 4A with Figures 5A and 6A, each of the interface circuits in the cartridges are unique to the particular vehicles for which the cartridges are applicable. Thus, for example, the interface circuit 112 includes a diagnostic enable line 114 which can be controlled in several different ways. Specifically, command signals generated at the microcomputer chip 72 will be transmitted to a versatile interface adapter circuit 116 (e.g. Rockwell 6522) via the cartridge bus structure 118 to vary the signal on the diagnostic enable line 114 in accordance with the diagnostic procedure desired by the operator. Specifically, the interface circuit 112 provides a "special mode" diagnostic enable line connected to pin PB4 of the VIA circuit 116 for directing the on-board vehicle computer to enter the special mode of operation. The special mode of operation is one used at the end of the assembly line to check systems before the vehicle is shipped. Selecting this special mode will cause certain engine functions to behave differently than they otherwise would. The special mode diagnostic line is connected to the diagnostic enable line 114 through an inverter 120 and a resistor 122 which will cause the amplitude of the voltage of the diagnostic enable line to change. The interface circuit 112 includes similar diagnostic mode selection lines for the "back-up mode" and "ground mode" enable features of various on-board vehicle computers. The interface circuit 112 includes several conductors which can receive data from the on-board vehicle computer. Thus, for example, the conductor labeled "CLCC data" is used to receive data from carbureted vehicles, while the conductor labeled "EFI data" is used to receive data from vehicles with fuel injection systems. The EFI data conductor is also connected to a serial in/out conductor 124 which operates as a high speed communication line to and from the on-board vehicle computer. This reflects the fact that in some on-board vehicle computers the EFI data is transmitted at high speeds (8192 baud or 9600 baud) . The interface circuit 112 also includes another conductor labeled "TCC solenoid" for receiving an indication when torque converter clutch lock-up command is given by th on-board vehicle computer. Each of the above dat reception conductors is connected to a buffered amplifie circuit such as buffered amplifier circuit 126 for the CLCC data conductor. A gating logic circuit 128 is also connected to the outputs of the buffered amplifier circuits for the CLCC data and EFI data conductors to permit the microcomputer chip 72 to select which of these two low speed data lines will be transmitting data to the microcomputer chip via "ALDL" data line 130.
The interface circuit 112 also includes a relay circuit 132 for causing a 5 volt pull-up signal to be transmitted to the on-board vehicle computer. A similar relay circuit 134 is used to operate the air control solenoid in the air management system of the vehicle. Each of these relay circuits includes a transistor which will close a relay when gated on by an appropriate command signal transmitted through the VIA chip 116 from the microcomputer chip 72.
It should also be noted that the cartridge circuit 110 includes a diode 136 which operates to protect the system 10 from any negative voltage being supplied from the vehicle. It may also be noted that the cartridge circuit 110 includes a number of metal oxide varistors ("MOV"), such as MOV 138. These metal oxide varistors are adapted to provide a lower resistance to higher voltage levels to protect the circuit from abnormal voltage surges. Turning to Figure 4B, the cartridge circuit 110 is shown to be provided with three memory circuits 140-144. The memory circuits 140-142 are each 32K by eight-bit EPROM chips, which operate as read only memories for storing a computer program which controls, at least in part, the accessing of data from the on-board vehicle computer. In other words, these memory chips 140-142 store the program which is used by the microcomputer chip 72 to appropriately communicate with the particular vehicles for which the cartridges are designed to be used for. While it may not presently be necessary for the cartridge to be provided with two separate 32 memory chips, they have been provided in this particular embodiment in order to provide added flexibility for future years when such additional memory space may eventually be required. Thus, for example, if only one of these memory chips is desired to be placed in the cartridge, appropriate jumpers 146 and 148 have been provided to readily alter the address requirements for these chips.
The memory chip 144 is preferably an 8 by eight-bit random access memory ("RAM") which can be used for storing a plurality of data streams received from the on-board vehicle computer. In this regard, it should be noted that the interface circuit 112 transmits the data received from the on-board vehicle computer first to the microcomputer chip 72, which then subsequently transmits this data back to the memory chip 144 for storage in a circular file which will permit the operator to scroll through a set of predetermined data parameters. The memory chip 144 is also used to permit the microcomputer chip 72 to preprocess the data being received from the on-board vehicle computer by verifying and checking these data streams.
The cartridge circuit 110 also features an electrical power storage device for enabling the memory circuit 144 to retain its stored data streams when electrical power is disconnected from the cartridge, such as when the cartridge is removed from the control station 12. Preferably this electrical power storage device comprises a large capacitor, such as the one farad capacitor 150 which is connected to the voltage input port of the memory chip 144. A diode 152 is connected between the 5 volt supply and the capacitor 150 to prevent the capacitor from being discharged into the 5 volt supply. While a battery could be used instead of the capacitor 150, the capacitor has the advantage of never having to be replaced as in the case of a battery. The cartridge circuit 110 also includes a reset circuit 154 which generates a reset signal on conductor 156 when power is first supplied to the cartridge. In this regard, the reset circuit 154 includes a capacitor 158 and a resistor 160 which combine to provide a time delay between the time that the power is first applied and the transistor 162 is gated on to provide the reset signal. The reset signal on line 156 is used to reset all of the chips in the cartridge as well as all of the chips in the control station which require resetting at start-up.
Figure 4B also indicates that the interface circuit 112 is provided with a high speed transmission circuit 164 for transmitting and receiving high speed data signals on conductor 124. A FET transistor 166 is provided in the transmission circuit 164 for switching the conductor 124 between an open state and a zero volt state. An inverter 168 is used to protect the FET transistor 166 from excessive dry currents or logic inversions. A pair of inverters 170-172 are used in the receiver line to act as a buffer which will protect the UART circuit contained in the microcomputer chip 72.
Referring to Figure 4C, the cartridge circuit 110 is shown to include an oscillator circuit 174 which is adapted to generate a 8192 baud rate signal on conductor 176. In this regard, the oscillator circuit 174 includes a 4.19304 megahertz crystal and a pair of ripple counters 178 and 180 which provide divide by four and divide eight functions respectively. Thus, it should be appreciated that the cartridge circuit 110 is capable of providing for one or more oscillator circuits which will enable or facilitate high speed data and other signal communications with the on-board vehicle computer. Referring to Figures 5A and 5B, a schematic diagram of a cartridge circuit 182 for diagnosing Chrysler manufactured vehicles is shown. For convenience, similar components to those described in connection with Figures 4A and 4B are primed in Figures 5A and 5B. In the case of cartridge circuit 182, a substantially simplified interface circuit 184 is provided. The interface circuit 184 includes a diagnostic enable or "read-hold" line 186 for transmitting a signal to the on-board vehicle computer which will cause the computer to transmit data to the system via data line 188. As in the case of the high speed data line 124 of the General Motors interface circuit 110, the VIA chip 116' is bypassed in order to transmit data directly to the microcomputer chip 72 contained in the control station 12. The interface circuit 184 also includes a relay circuit 190 for transmitting an actuator signal to the on-board vehicle computer under software control. Figure 5A also shows that the cartridge circuit 182 may include an oscillator circuit 192 for generating 976 baud and 7812 baud clock signals.
Referring to Figures 6A-6B, a cartridge circuit 194 for diagnosing Ford manufactured vehicles is shown. The cartridge circuit 194 includes an interface circuit generally designated by the reference numeral 196. The interface circuit includes a relay circuit 198 for closing a relay which will cause a "latch" signal to be transmitted to the on-board vehicle computer for causing the on-board vehicle computer to transmit data to the system. The interface circuit 196 also includes a buffered amplifier circuit 126" for receiving data transmitted from the on-board vehicle computer. The interface circuit 196 further includes a "SONALERT" circuit 200 for causing a chirping or beeping sound to emanate from a sonalert device 202 during the transmission of data from the on-board vehicle computer to the system 10. Specifically, the microcomputer chip 72 will transmit a sonalert command through the VIA circuit 116" to a NAND gate 204. The output state of the NAND gate 204 will be toggled HIGH and LOW in response to the gating on and off of the transistor contained in the buffered amplifie circuit 126". From the above it should be appreciate that the VIA chips 116, 116' and 116" provide a communication link between the data lines of the bus structure of the control station and the application specific interface circuits of the cartridges. Additionally, while the entire computer program for operating the system 10 can be stored in the EPROM circuits 140-142, it should be appreciated that the microcomputer chip 72 or other appropriate microcomputer circuit may additionally be provided with read only memory for storing common portions of the program needed to enable the control station to operate.
The various embodiments which have been set forth above were for the purpose of illustration and were not intended to limit the invention. It will be appreciated by those skilled in the art that various changes and modifications may be made to these embodiments described in this specification without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. An interchangeable diagnostic instrument system capable of communicating with on-board vehicle computers from vehicles of different manufacturers, comprising: a universal communications control station having a portable housing, actuator means for permitting an operator to direct a diagnostic test procedure, display means for selectively displaying data received from said on-board vehicle computer, and microcomputer circuit means in communication with said actuator means and said display means for executing said diagnostic test procedure; and a removable cartridge having a housing connected to said portable housing of said control station, interface means for receiving data from said on-board vehicle computer, and programmed memory means for storing a computer program which controls, at least in part, the accessing of data from said on-board vehicle computer, said interface means and said programmed memory means being in communication with said microcomputer circuit means of said control station.
2. The interchangeable diagnostic instrument system according to Claim 1, wherein said cartridge includes random access memory means in communication with said microcomputer circuit means for storing a plurality of said data streams.
3. The interchangeable diagnostic instrument system according to Claim 2, wherein said cartridge includes electrical power storage means for enabling said random access memory means to retain said stored data streams when electrical power is disconnected from said cartridge.
4. The interchangeable diagnostic instrument syste according to Claim 3, wherein said electrical powe storage means comprises a capacitor.
5. An interchangeable diagnostic instrument syste capable of communicating with on-board vehicl computers from vehicles of different manufacturers, comprising: a universal communications control statio having a portable housing, actuator means fo permitting an operator to direct a diagnostic test procedure, display means for selectively displaying data received from said on-board vehicle computer, microcomputer circuit means in communication with said actuator means and said display means for executing said diagnostic test procedure, and first terminal means for enabling signals to be transmitted to and from said on-board vehicle computer; and a removable cartridge having a housing connected to said portable housing of said control station, interface means in communication with said first terminal means for causing said on-board vehicle computer to transmit a stream of data and for receiving said stream of data, and programmed memory means for storing a computer program which controls, at least in part, the accessing of data from said on-board vehicle computer, said interface means and said programmed memory means being in communication with said microcomputer circuit means of said control station.
6. The interchangeable diagnostic instrument system according to Claim 5, wherein said stream of data is transmitted from said first terminal means of said control station directly to said interface means of said cartridge.
7. The interchangeable diagnostic instrument system according to Claim 6, wherein said first terminal means includes pin means for receiving electrical power, and bus means for transmitting said electrical power directly to said cartridge, such that electrical power to said control station is terminated when said cartridge is removed from said control station.
8. The interchangeable diagnostic instrument system according to Claim 5, wherein said cartridge includes random access memory means in communication with said microcomputer circuit means for storing a plurality of said data streams.
9. The interchangeable diagnostic instrument system according to Claim 8, wherein said cartridge includes electrical power storage means for enabling said random access memory means to retain said stored data streams when electrical power is disconnected from said cartridge.
10. The interchangeable diagnostic instrument system according to Claim 9, wherein said electrical power storage means comprises a capacitor.
11. The interchangeable diagnostic instrument system according to Claim 5, wherein said control station includes communication circuit means connected to said microcomputer circuit means for enabling said control station to transmit data streams from said on-bόard vehicle computer to an external device.
12. The interchangeable diagnostic instrument system according to Claim 11, wherein said communication circuit means includes a UART for providing serial communication with said external device.
13. The interchangeable diagnostic instrument syste according to Claim 5, wherein said display mean comprises an LCD display, and said control statio includes contrast circuit means for adjusting th viewing angle of said LCD display under the contro of said microcomputer circuit means.
14. The interchangeable diagnostic instrument syste according to Claim 13, wherein said contrast circui means includes timer means for generating a puls signal having a frequency controlled by a comman signal from said microcomputer circuit means, an converter means for converting said pulse signal to voltage signal whose amplitude is related to th frequency of said pulse signal.
15. The interchangeable diagnostic instrument syste according to Claim 5, wherein said interface means includes oscillator means for generating a cloc signal for enabling said system to communicate with said on-board vehicle computer at a baud rate determined by the frequency of said clock signal.
16. The interchangeable diagnostic instrument system according to Claim 5, wherein said cartridge housing is connected to said control station along a substantial length of said portable housing.
17. The interchangeable diagnostic instrument system according to Claim 16, wherein a back surface of said cartridge housing extends generally along a rear surface of said portable housing.
18. The interchangeable diagnostic instrument system according to Claim 17, wherein said cartridge housing is contained generally within the outline of said portable housing.
19. The interchangeable diagnostic instrument system according to Claim 5, wherein said cartridge housing has a width sufficient to contain two circuit boards extending generally in parallel with each other.
20. A removable cartridge for enabling a communications control station to access data from predetermined on-board vehicle computers, comprising: a housing; terminal means extending generally from one end of said housing for providing a plurality of electrical signal connections with said communications control station; interface means in communication with said terminal means for causing at least one predetermined on-board vehicle computer to transmit a stream of data and for receiving said stream of data; and programmed memory means in communication with said terminal means for storing a computer program which controls, at least in part, the accessing of data from said predetermined on-board vehicle computer.
PCT/US1989/000042 1988-01-15 1989-01-11 Interchangeable diagnostic instrument system WO1989006839A1 (en)

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US14426988A 1988-01-15 1988-01-15
US144,269 1988-01-15

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CN110596627A (en) * 2019-08-22 2019-12-20 深圳市鹏巨术信息技术有限公司 Detection method and device for vehicle diagnosis box
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Cited By (21)

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EP0661673A1 (en) * 1993-12-28 1995-07-05 Valeo Electronique Method for managing the maintenance of a vehicle, on-board computer and associated diagnostic station for performing the method
FR2714506A1 (en) * 1993-12-28 1995-06-30 Valeo Electronique A method of managing the maintenance of a vehicle, on-board computer and associated diagnostic station implementing the method.
US5683261A (en) * 1994-05-19 1997-11-04 Spx Corporation Removable coupling module for mechanically multiplexing conductors
WO1998008103A1 (en) * 1996-08-22 1998-02-26 Robert Bosch Gmbh Diagnostic procedure for electrical appliances
US6421631B1 (en) 1996-08-22 2002-07-16 Robert Bosch Gmbh Diagnostic procedure for electrical appliances
US6401049B1 (en) 1996-09-04 2002-06-04 Continental Teves Ag & Co., Ohg Process for inspecting the components of a system in a motor vehicle
WO1998010300A1 (en) * 1996-09-04 1998-03-12 Itt Manufacturing Enterprises, Inc. Process for inspecting the components of a system in a motor vehicle
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DE19731283B4 (en) 1997-07-21 2018-07-26 Bayerische Motoren Werke Aktiengesellschaft Diagnostic test device for electronic control units in different motor vehicle types
EP0893697A3 (en) * 1997-07-21 1999-02-10 Bayerische Motoren Werke Aktiengesellschaft, Patentabteilung AJ-3 Dispositif de test diagnostique pour des unités de commande électronique dans différents types de véhicules automobiles
EP0893697A2 (en) * 1997-07-21 1999-01-27 Bayerische Motoren Werke Aktiengesellschaft, Patentabteilung AJ-3 Dispositif de test diagnostique pour des unités de commande électronique dans différents types de véhicules automobiles
WO2002010782A2 (en) * 2000-07-19 2002-02-07 Volkswagen Aktiengesellschaft Method and device for checking for errors in electrical lines and/or electrical consumers in a vehicle
WO2002010782A3 (en) * 2000-07-19 2002-05-23 Volkswagen Ag Method and device for checking for errors in electrical lines and/or electrical consumers in a vehicle
EP1715459A2 (en) * 2005-04-21 2006-10-25 Motorscan S.p.A. Device for the diagnosis of a central unit of an air conditioning system of a vehicle
EP1715459A3 (en) * 2005-04-21 2007-01-17 Motorscan S.p.A. Device for the diagnosis of a central unit of an air conditioning system of a vehicle
WO2007045884A1 (en) * 2005-10-20 2007-04-26 Airmax Group Plc Methods and apparatus for monitoring vehicle data
US9589395B2 (en) * 2009-11-02 2017-03-07 Bosch Automotive Service Solutions Inc. Tool interface connector wireless adapter compact design
US20110106371A1 (en) * 2009-11-02 2011-05-05 Lee Jardine Tool interface connector wireless adapter compact design
CN106530439A (en) * 2016-10-21 2017-03-22 钟立朋 Anti-static anti-shock driving instrument shell
CN110596627A (en) * 2019-08-22 2019-12-20 深圳市鹏巨术信息技术有限公司 Detection method and device for vehicle diagnosis box
US11574510B2 (en) 2020-03-30 2023-02-07 Innova Electronics Corporation Multi-functional automotive diagnostic tablet with interchangeable function-specific cartridges

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