Multi-layer state machine for a hybrid real-time control system and method of operation thereof

• US 6,317,638 B1
• Filed: 08/22/1997
• Issued: 11/13/2001
• Est. Priority Date: 08/22/1997
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Schreder, James M., Rudnick, Jurgen, McLaughlin, Paul F., Mody, Pankaj H.
• Primary Examiner(s): Treat, William M.
• Application Number:
  US08/920,266
• Time in Patent Office: 1,544 Days
• Field of Search: 395/800.32, 395/800.39, 395/800.4, 395/740, 395/734, 395/672, 395/746, 712/32, 712/39, 712/40, 714/769, 714/802, 714/815, 714/825
• US Class Current: 700/79
• CPC Class Codes: G05B 19/042 using digital processors G05B19/05 takes precedence
• CPC Class Codes: G06F 9/4843 by program, e.g. task dispatcher, supervisor, operating system
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications

Abstract

Various system architectures for a state machine-based, hybrid real-time control system, and methods of operation thereof, are disclosed. In one embodiment of a system architecture for use with a state machine capable of controlling a real-time process and having a plurality of states and handlers that govern transitions between ones of the plurality of states, a system for invoking one of the handlers includes an invoke transition that monitors conditions of the real-time process, the invoke transition causing the automatic invocation of the handler when the conditions match predetermined conditions under which the handler is to be invoked, the invoke transition thereby allowing the handler to be invoked without an explicit command.

Claims

1. For use with a state machine capable of controlling a real-time process within a process control system and having a plurality of states and handlers that govern transitions between ones of said plurality of states, a system for invoking one of said handlers, comprising:

an invoke transition, external to said one of said handlers, that monitors conditions of said real-time process and provides for state-driven abnormal functions by automatically invoking said one of said handlers when said conditions match a predetermined condition under which said one of said handlers is to be invoked, said invoke transition thereby allowing said one of said handlers to be invoked without providing an explicit command to a sequence control object.

2. The system as recited in claim 1 wherein said invoke transition is contained within a transition block of said one of said handlers.

3. The system as recited in claim 1 wherein said invoke transition is embodied in a sequence of instructions executable in data processing and storage circuitry.

4. For use with a state machine capable of controlling a real-time process within a process control system and having a plurality of states and handlers that govern transitions between ones of said plurality of states, a method of invoking one of said handlers, comprising the steps of:

monitoring at least one condition of said real-time process;

comparing, with an invoke transition that is external to said one of said handlers, a predetermined condition under which said one of said handlers is to be invoked with said at least one monitored condition; and

providing state-driven abnormal functions by automatically invoking said one of said handlers if said at least one monitored condition matches said predetermined condition, whereby said one of said handlers is invoked without providing an explicit command to a sequence control object.

5. The method as recited in claim 4 wherein said predetermined condition is dynamically-altered as a function of a condition of said real-time process.

6. The method as recited in claim 4 wherein said steps of monitoring, comparing and automatically invoking are performed by executing a sequence of instructions in data processing and storage circuitry.

7. For use with a state machine capable of controlling a device as part of a real-time process within a process control system and having a plurality of states, a system for driving said device to a particular state, said system comprising:

a state machine monitor, associated with said device and external to said state machine, that monitors a state of said state machine; and

a device state controller, associated with said device and coupled to said state machine monitor, that provides state-driven abnormal functions by driving said device to said particular state based on said state of said state machine, said state machine thereby freed of having to sequence-drive said device to said particular state by providing an explicit command to a sequence control object.

8. The system as recited in claim 7 wherein said device state controller drives said device in an abnormal function.

9. The system as recited in claim 7 wherein said state machine and said device exist in different architectural layers within a hybrid real-time control system.

10. For use with a state machine capable of controlling a device as part of a real-time process within a process control system and having a plurality of states, a method of invoking one of said handlers, comprising the steps of:

monitoring a state of said state machine with a state machine monitor that is external to said state machine; and

providing state-driven abnormal functions by driving said device to a particular state based on said state of said state machine, said state machine thereby freed of having to sequence-drive said device to said particular state by providing an explicit command to a sequence control object.

11. The method as recited in claim 10 wherein said step of driving comprises the step of driving said device in an abnormal function.

12. The method as recited in claim 10 wherein said state machine and said device exist in different architectural layers within a hybrid real-time control system.

13. For use with hybrid real-time process control system having at least first and second architectural layers, a system for coordinating functions between said layers, comprising:

inter-layer monitors, associated with objects within each of said architectural layers, that receive state and assignment information of monitored objects in other architectural layers; and

object controllers, coupled to said inter-layer monitors, that provides state-driven abnormal functions, subject to reservation of said objects, by governing operation of said objects based on said state and assignment information of said monitored objects.

14. The system as recited in claim 13 wherein said assignment information includes reservation information regarding whether devices associated with said monitored objects have been reserved, said object controllers capable of reserving said devices only when said reservation information indicates that said devices are unreserved.

15. The system as recited in claim 13 wherein said object controllers are capable of ignoring requests from unauthorized objects.

16. The system as recited in claim 13 wherein said object controllers contain information regarding a state previously attained by said objects.

17. The system as recited in claim 13 wherein said first layer is selected from the group consisting of a unit executive layer and a device layer and said second layer is a sequence layer.

18. The system as recited in claim 13 wherein said object controllers are capable of changing mode in response to mode changes occurring in said other architectural layers.

19. For use with hybrid real-time process control system having at least first and second architectural layers, a method of coordinating functions between said layers, comprising the steps of:

receiving state and assignment information of monitored objects in other architectural layers into each architectural layer; and

providing state-driven abnormal functions by governing operation of objects based on said state and assignment information subject to reservation of said objects.

20. The method as recited in claim 19 wherein said assignment information includes reservation information regarding whether devices associated with said monitored objects have been reserved, said method comprising the step of reserving said devices only when said reservation information indicates that said devices are unreserved.

21. The method as recited in claim 19 further comprising the step of ignoring requests from unauthorized objects.

22. The method as recited in claim 19 further comprising the step of storing a state previously attained by said objects.

23. The method as recited in claim 19 wherein said first layer is selected from the group consisting of a unit executive layer and a device layer and said second layer is a sequence layer.

24. The method as recited in claim 19 further comprising the step of changing mode in response to mode changes occurring in said other architectural layers.

25. A state machine capable of providing state-driven abnormal functions by controlling a real-time process within a process control system and having a stopped state and a transition to said stop state, comprising:

a handler that provides a transition from said stopped state toward a running state, said handler allowing said state machine to recover from said stop state without having to abort from said stopped state.

26. The machine as recited in claim 25 wherein said stopped state is an abnormal state and said handler is embodied in a sequence of instructions executable in data processing and storage circuitry.

27. The machine as recited in claim 25 wherein said handler is capable of being automatically invoked.

28. The machine as recited in claim 25 wherein said transition leads to a configurable location in a sequence.

29. A method of operating a state machine capable of providing state-driven abnormal functions by controlling a real-time process within a process control system and having a stopped state and a transition to said stop state, comprising the steps of:

providing a transition from said stopped state toward a running state; and

recovering said state machine from said stop state via said transition from said stopped state without having to abort from said stopped state.

30. The method as recited in claim 29 wherein said stopped state is an abnormal state and said method is carried out by executing a sequence of instructions in data processing and storage circuitry.

31. The method as recited in claim 29 wherein said step of recovering comprises the step of automatically invoking a handler.

32. The machine as recited in claim 29 wherein said transition leads to a configurable location in a sequence.

33. A state machine capable of providing state-driven abnormal functions by controlling a device as part of a real-time process within a process control system, comprising:

a first layer exception and current transition and current step objects; and

a second layer of condition, interrupt/step condition and output objects, said state machine thereby organized into a multi-object aggregation hierarchy.

34. The state machine as recited in claim 33 wherein said condition objects of said second layer are associated with said exception transition objects of said first layer.

35. The state machine as recited in claim 33 wherein said condition objects of said second layer are associated with said current transition objects of said first layer.

36. The state machine as recited in claim 33 wherein said interrupt/stop condition objects of said second layer are associated with said current step objects of said first layer.

37. The state machine as recited in claim 33 wherein said output objects of said second layer are associated with said current step objects of said first layer.

38. A method of operating a state machine capable of providing state-driven abnormal functions by controlling a device as part of a real-time process within a process control system, comprising the steps of:

processing information relating to said real-time process in a first layer of exception and current transition and current step objects; and

processing information relating to said real-time process in an associated second layer of condition, interrupt/step condition and output objects, said state machine thereby organized into a multi-object aggregation hierarchy.

39. The method as recited in claim 38 wherein said condition objects of said second layer are associated with said exception transition objects of said first layer.

40. The method as recited in claim 38 wherein said condition objects of said second layer are associated with said current transition objects of said first layer.

41. The method as recited in claim 38 wherein said interrupt/stop condition objects of said second layer are associated with said current step objects of said first layer.

42. The method as recited in claim 38 wherein said output objects of said second layer are associated with said current step objects of said first layer.