System and method for communicating data between control unit and master station applicable to automotive vehicle

• US 5,200,745 A
• Filed: 10/02/1990
• Issued: 04/06/1993
• Est. Priority Date: 10/09/1989
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Inagaki, Hidetoshi, Futami, Toru, Takai, Hideo
• Primary Examiner(s): Yusko, Donald J.
• Assistant Examiner(s): Magistre, Dervis
• Application Number:
  US07/591,515
• Time in Patent Office: 917 Days
• Field of Search: 364/424.03, 364/424.04, 340/438, 340/439, 340/825.65, 340/825.06, 340/825.07, 340/825.12, 340/825.14, 340/825.16, 340/825.17
• US Class Current: 340/12.18
• CPC Class Codes: G05B 19/0421 Multiprocessor system
• CPC Class Codes: G05B 2219/2231 Master slave
• CPC Class Codes: G05B 2219/25156 Full echo communication check, echo back
• CPC Class Codes: G05B 2219/25158 Watchdog

Abstract

A system and method for communicating data between a master station and a plurality of control units applicable to an automotive vehicle are disclosed in which if an echoback communication in response to a control command is not received by the master station from the selected control unit within a predetermined period of time upon issuance of a continue command or a diagnostic execution command, the controlled state of the electronic control unit is released. Furthermore, to effectively diagnose the control operation of one of the control units interactively with the operation of other control units, an interrupt command may be issued while the selected control unit continues the predetermined control operation, and the remaining control units are then initialized. A different control unit may then be selected and set to a controlled state. While the second selected control unit is in the controlled state an interrupt command may be issued, thus maintaining the second selected control unit in a controlled state. A resume command is then issued to resume communication with the first selected control unit which has been maintained in a controlled state, so that the control operation of a control unit which is affected by the operation of any one of the other control units can appropriately be diagnosed.

Claims

1. A system for communicating data between a master station and any one of a plurality of control units,

wherein said master station includes:

a) first means for selecting a control unit from among a plurality of control units and for transmitting a selection command to the selected control unit to establish a communication state between the master station and the selected control unit;

b) second means for transmitting a control command to the selected control unit instructing the selected control unit to perform a predetermined control operation;

c) third means for transmitting a diagnostic execution command to the selected control unit instructing the selected control unit to send monitor data relating to the predetermined control operation to the master station; and

d) fourth means for repeatedly transmitting a continuation command to the selected control unit for enabling the continuation of the predetermined control operation by the selected control unit, said fourth means repeatedly transmitting said continuation command at least once within a predetermined interval of time for every repetition of said predetermined interval of time; and

wherein said selected control unit includes;

fifth means for counting an elapsed time upon receipt of either of the continuation command or the diagnostic execution command from the master station and for terminating the predetermined control operation when the counted time exceeds a predetermined interval of time during which no continuation command is received thereat.

2. A system as set forth in claim 1, wherein said fifth means is contained in each of said control units.

3. A system as set forth in claim 1, wherein the fourth means transmits the continuation command to the selected control unit within the predetermined interval of time after transmission of the diagnostic execution command.

4. A system as set forth in claim 3, wherein the fifth means comprises a timer counting an elapsed time in response to the receipt of the diagnostic execution command.

5. A system as set forth in claim 4, wherein the master station further includes:

sixth means for selectively transmitting an end command instructing the selected control unit to terminate the predetermined control operation and the communication state;

seventh means for selectively transmitting an interruption command, instructing the selected control unit to interrupt the communciation state while continuing the predetermined control operation; and

eighth means for transmitting a resumption command instructing the selected control unit to resume the communication state interrupted by the interruption command.

6. A system as set forth in claim 5, wherein the master station further includes ninth means for intermittently transmitting two initialize commands to all control units to initialize all control units and to instruct all control units to enter command wait states.

7. A system as set forth in claim 6, wherein the selected control units further includes tenth means for returning a reply signal to the master station which is a reverse signal of the selection command to confirm that the selected control unit has received the selection command.

8. A system as set forth in claim 7, wherein the control command includes a monitor item command which is issued from the master station to the selected control unit to monitor internal data from the selected control unit, including at least one information byte indicating an item of control being subsequently transmitted to the selected control unit.

9. A system as set forth in claim 8, wherein the selected control unit issues a reversed control command to the master station upon receipt of the control command.

10. A system as set forth in claim 9, wherein the selected control unit further includes eleventh means for returning a reversed signal of the interruption command to the master station while the selected control unit performs the predetermined control operation.

11. A system as set forth in claim 10, wherein two initialize commands are issued from the master station to all control units except the presently selected control unit after the selected control unit issues the reversed interruption command to the master station.

12. A system as set forth in claim 11, wherein another selection command is issued from the master station to any one of the other control units other than a control unit which has received an interrupt signal.

13. A system as set forth in claim 12, wherein the control commands include a parameter set command to command the selected control unit to command a controlled variable of the selected control unit to be set in a particular state, at least one information byte being subsequently transmitted to the selected control unit.

14. A system as set forth in claim 13, wherein after another control unit is newly selected after the interruption command is issued to a previously selected control unit, the newly selected control unit issues a reversed interruption command to the master station and the master station issues a resume command to the previously selected control unit for which communication with the master station was interrupted.

15. A system as set forth in claim 14, wherein the system is applied to control operations of an automotive vehicle.

16. A system for communicating data between a master station and any one of a plurality of control units,

wherein said master station includes:

a) first means for selecting a control unit from among a plurality of control units and for transmitting a selection command to the selected control unit to establish a communication state between the master station and the selected control unit;

b) second means for transmitting a control command to the selected control unit instructing the selected control unit to perform a predetermined control operation;

c) third means for selectively transmitting an end command to the selected control unit instructing the selected control unit to terminate the predetermined control operation and the communication state;

d) fourth means for selectively transmitting an interruption command to the selected control unit instructing the selected control unit to interrupt the communication state and to continue the predetermined control operation; and

d) fifth means for transmitting a resume command to the selected control unit instructing the selected control unit to resume the communication state which was interrupted in response to the interruption command.

17. A system as set forth in claim 16, wherein the master station further includes sixth means for intermittently transmitting two initialize commands to all control units to initialize all control units and to instruct all control units to enter command wait states.

18. A system as set forth in claim 17, wherein the selected control unit includes seventh means for returning a reply signal to the master station which is a reverse signal of the selection command to confirm that the selected control unit has received the selection command.

19. A system as set forth in claim 18, wherein the control command includes a monitor:

item command which is issued from the master station to the selected control unit to monitor internal data from the selected control unit, including at least one information byte indicating an item of control being subsequently transmitted to the selected control unit.

20. A system as set forth in claim 19, wherein the selected control unit issues a reversed control command to the master station upon receipt of the control command.

21. A system as set forth in claim 20, wherein the master station further includes eighth means for transmitting a diagnostic execution command to the selected control unit instructing the selected control unit to monitor the internal data of the selected control unit so as to confirm whether the predetermined control operation is carried out in the selected control unit.

22. A system as set forth in claim 21, wherein the selected control unit includes ninth means for returning a reversed signal of the interruption command to the master station while the selected control unit performs the predetermined control operation.

23. A system as set forth in claim 22, wherein two initialize commands are issued from the master station to all control units except the presently selected control unit after the selected control unit issues the reversed interruption command to the master station.

24. A system as set forth in claim 23, wherein another selection command is issued from the master station to any one of the other control units other than a control unit which has received an interrupt signal.

25. A system as set forth in claim 24, wherein the control commands include a parameter set command to command the selected control unit to command a controlled variable of the selected control unit to be set in a particular state, at least one information byte being subsequently transmitted to the selected control unit.

26. A system as set forth in claim 25, wherein after another control unit is newly selected after the interruption command is issued to a previously selected control unit, the newly selected control unit issues a reversed interruption command to the master station and the master station issues a resume command to the previously selected control unit for which communication with the master station was interrupted.

27. A system as set forth in claim 16, wherein the master station further includes sixth means for transmitting a continuation command to the selected control unit for enabling the continuation of the predetermined control operation by the selected control unit, and the selected control unit includes seventh means for counting a preselected time interval upon the receipt of either the control command or the continuation command and for terminating the predetermined control operation when the counted time exceeds the predetermined time interval.

28. A system as set forth in claim 27, wherein said seventh means is contained in each of said control units.

29. A system as set forth in claim 28, wherein the master station further includes eighth means for transmitting a diagnostic execution command to the selected control unit after the control command has been issued from the master station, and wherein the sixth means issues the continuation command after the diagnostic execution command has been issued.

30. A method for communicating data between a master station and a plurality of control units, comprising:

a) selecting a control unit from among a plurality of control units and transmitting a selection command to the selected control unit to establish a communication state;

b) transmitting a control command instructing the selected control unit to perform a predetermined control operation;

c) transmitting a diagnostic execution command instructing the selected control unit to monitor data relating to performance of the predetermined control operation;

d) periodically transmitting a continuation command instructing the selected control unit to continue the predetermined control operation; and

e) counting an elapsed time upon the receipt of either of the continuation command or the diagnostic execution command and terminating the control operation when the counted time exceeds a predetermined interval of time during which no continuation command is received by the selected control unit.