Function block apparatus for viewing data in a process control system

• US 6,285,966 B1
• Filed: 06/25/1998
• Issued: 09/04/2001
• Est. Priority Date: 06/25/1998
• Status: Expired due to Term

• Current Assignee: Fisher Controls International LLC (Emerson Electric Company)
• Original Assignee: Fisher Controls International LLC (Emerson Electric Company)
• Inventors: Larson, Brent H., Brown, Larry K., Burns, Harry A.
• Primary Examiner(s): SHAH, KAMINI S
• Application Number:
  US09/105,333
• Time in Patent Office: 1,167 Days
• Field of Search: 702/182, 702/188, 702/122, 340/870.11, 709/103
• US Class Current: 702/188
• CPC Class Codes: G05B 19/0425 Safety, monitoring
• CPC Class Codes: G05B 19/406 characterised by monitoring or safety G05B19/19 takes precedence
• CPC Class Codes: G05B 19/4185 characterised by the network communication
• CPC Class Codes: G05B 2219/25428 Field device
• CPC Class Codes: G05B 2219/31121 Fielddevice, field controller, interface connected to fieldbus
• CPC Class Codes: G05B 2219/31122 Bridge between networks
• CPC Class Codes: G05B 2219/31135 Fieldbus
• CPC Class Codes: G05B 2219/31436 Host monitors plc, control processor without interrupting its program
• CPC Class Codes: G05B 2219/31455 Monitor process status
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

The present invention is directed to a method of and a device for monitoring, from a central location, the current operating conditions (such as values of process parameters) in a process control network having distributed control functions. In one embodiment, the method and device of the present invention use scheduled periodic communications to send signals containing, for example, measured values of process parameters developed by field devices to a centralized viewing device. The viewing device receives the signals and stores at least one value of the process parameters, and maybe more values if necessary to monitor and control the process. To retrieve the stored process parameters for viewing, the viewing device processes messages from human interface devices requesting the stored values of one or more of the stored parameters and then transmits response messages containing the stored values. The human interface device may be the same device as the viewing device, or may be a separate device that communicates with the viewing device using either the same or a different communication protocol as that used by the field devices to communicate with the viewing device. Additionally, the request and response messages may be sent between the devices using unscheduled queued communications.

Claims

1. A method of viewing real time process information in a process control network having a plurality of devices communicatively linked on a bus, wherein each of the devices includes at least one process function module capable of performing a process control function within the process control network using process parameters and capable of communicating on the bus using scheduled periodic communications, and wherein at least one of the devices includes a viewing process function module capable of storing values of process parameters without using the values to perform process control, of being configured by a user to store at least one process parameter, and of retrieving values of the process parameters in response to a request generated by a user selecting at least one process parameter from a plurality of selectable process parameters, the method comprising the steps of:

configuring the viewing process function module to store at least one value of each of at least one process parameter, each of the at least one process parameter being associated with one of the process function modules;

communicatively linking an output of each of the process function modules associated with each of the at least one process parameter to an input of the viewing process function module using the scheduled periodic communications;

transmitting a value of the at least one process parameter from the associated process function module to the viewing process function module using the scheduled periodic communications; and

storing the transmitted value of the at least one process parameter in the viewing process function module.

2. A method of viewing real time process information in a process control network according to claim 1, wherein the at least one process parameter is a plurality of process parameters.

3. A method of viewing real time process information in a process control network according to claim 1, further comprising the steps of:

configuring the viewing process function module to store information associated with the at least one process parameter; and

transmitting information associated with the at least one process parameter to the viewing process function module concurrently with the value of the at least one process parameter.

4. A method of viewing real time process information in a process control network according to claim 1, wherein the transmitting step further comprises the step of transmitting a value of the at least one process parameter from the associated process function module to a plurality of process function modules using the scheduled periodic communications.

5. A method of viewing real time process information in a process control network according to claim 1, wherein the viewing process function module is a viewing function block in a Fieldbus protocol.

6. A method of viewing real time process information in a process control network according to claim 1, further comprising the steps of:

connecting at least one device including an output process function module having a human interface to the bus;

communicatively linking an output of the at least one output process function module to the viewing process function module using the unscheduled queued communications;

transmitting requests for at least one stored value of the at least one process parameter from the at least one output process function module to the viewing process function module using the unscheduled queued communications,

communicatively linking the output of the viewing process function module to an input of the at least one output process function module using the unscheduled queued communications;

transmitting a response containing the at least one stored value of the at least one process parameter from the viewing process function module to the at least one output function process function module using the unscheduled queued communications; and

displaying the at least one stored value of the process parameter at the human interface of the at least one output process function modules.

7. A method of viewing real time process information in a process control network according to claim 6, wherein the at least one display device comprises a plurality of display devices, each of the display devices including an output process function module having a human interface.

8. A method of viewing real time process information in a process control network according to claim 6, wherein the at least one display device is the at least one of the devices including the viewing process function module.

9. A method of viewing real time process information in a process control network according to claim 1, the method further comprising the steps of:

connecting the at least one of the devices to a second bus of a second process control network, wherein each of the devices connected to the second bus is capable of communicating on the second bus using unscheduled queued communications;

connecting a display device including an output process function module having a human interface to the second bus of the second process control network;

communicatively linking an output of the output process function module to the viewing process function module using the unscheduled queued communications;

transmitting a request for at least one stored value of the at least one process parameter from the output process function module to the viewing process function module using the unscheduled queued communications;

communicatively linking an output of the viewing process function module to an input of the output process function module using the unscheduled queued communications;

transmitting a response containing the at least one stored value of the at least one process parameter from the viewing process function module using the unscheduled queued communications; and

displaying the at least one stored value of the at least one process parameter at the human interface.

10. An information viewing system for viewing real time values of process parameters in a process control network having a plurality of devices communicatively linked over a bus, wherein each of the devices is capable of performing a process function and of communicating on the bus using scheduled and unscheduled periodic communications, the information viewing system comprising:

a first signal generator disposed in a first device that generates input signals including values of at least one process parameter associated with the first device;

a first communicator coupled to the first signal generator and configured to deliver the input signals to an input of a second device using scheduled periodic communications;

a data capture unit disposed in the second device that receives the input signals;

a storage unit disposed in the second device and communicatively linked to the data capture unit, the storage unit adapted to store at least one value of at least one process parameter without using the at least one value to perform process control;

a second signal generator disposed in one of the first device, the second device and a third device that generates request signals requesting at least one value of one or more of the at least one process parameter stored in the storage unit wherein the request signals are generated in response to a user selecting process parameters from a plurality of selectable process parameters;

a second communicator coupled to the second signal generator and configured to deliver the request signals to an input of the second device using the unscheduled queued communications, the request signals being received by the data capture unit;

a data transfer unit disposed in the second device that generates response signals including the requested values of the one or more of the at least one process parameter from the storage unit;

a third communicator coupled to the data transfer unit and configured to deliver the response signals to an input of the one of the first device, the second device and third device using the unscheduled queued communications;

a signal receiver that receives the response signals generated by the data transfer unit; and

a display device disposed in the one of the first device, the second device and the third device that displays the requested values of the one or more of the at least one process parameter at a human interface.

11. An information viewing system according to claim 10, wherein the data transfer unit is communicatively linked to the data capture unit and the storage unit and adapted to receive the values of the at least one process parameter from the data capture unit and to cause the storage unit to overwrite the stored value of the at least one process parameter with the received values.

12. An information viewing system according to claim 11, wherein the data transfer unit is adapted to configure the storage unit to store at least one value of at least one process parameter, and further comprising an input host interface disposed in the second device and communicatively linked to the data transfer unit, the input host interface adapted to transfer process parameter configuration instructions to the data transfer unit, whereby the process parameter configuration instructions cause the data transfer unit to configure the storage unit to store at least one value of at least one process parameter.

13. An information viewing system according to claim 10, wherein the at least one process parameter is a plurality of process parameters and the information viewing system further comprises a plurality of first devices each having a first signal generator disposed therein that generates input signals including values of process parameters associated with the first device, wherein the data capture unit receives each of the input signals and the storage unit one of overwrites and appends a stored value of a process parameter with a value of the process parameter transmitted in the corresponding input signal by the associated first device.

14. An information viewing system according to claim 10, wherein the input signal includes information associated with the at least one process parameter and the storage unit one of overwrites and appends a stored value of the associated information stored therein with the value of the associated information in the input signal.

15. An information viewing system according to claim 10, wherein the first communicator is configured to deliver the input signal to a plurality of devices using the scheduled periodic communications.

16. An information viewing system according to claim 10, further comprising a plurality of third devices each having a second signal generator disposed therein that generates request signals requesting values of one or more of the at least one process parameter contained in the storage unit.

17. An information viewing system according to claim 10, wherein the third device is connected to the second device by a second bus of a second process control network wherein each of the devices is capable of communicating on the second bus using unscheduled periodic communications.

18. A viewing process function module capable of being implemented in a process control device and of being used in a process control network having a plurality of devices communicatively coupled to a bus, wherein each of the devices includes at least one process function module capable of performing an input function, an output function, or a control function within the process control network and capable of communicating on the bus using scheduled and unscheduled periodic communications, the viewing process function module comprising:

a data capture unit that receives input signals, wherein each input signal is generated by one of the process function modules, contains a value of a process parameter associated with the process function module, and is transmitted using the scheduled periodic communications;

a storage unit that stores at least one value of at least one process parameter without using the at least one value to perform process control;

a data transfer unit that causes the values of the process parameters in the input signals to be stored in the storage unit;

an output host interface that receives request signals containing requests for at least one stored value of one or more of the at least one process parameter requested by a user from a plurality of selectable process parameters, the request signals generated by at least one of the devices and transmitted using the unscheduled queued communications,wherein the output host interface transfers the request signal to the data transfer unit;

wherein the data transfer unit retrieves the at least one stored value of the at least one process parameter from the storage unit and transfers the at least one stored value to the output host interface in response to each request signal; and

wherein the output host interface generates a response signal containing the at least one stored value of the one or more of the at least one process parameter and transmits the response signal to the second one of the devices using the unscheduled queued communications in response to each request signal.

19. A viewing process function module according to claim 18, wherein the data capture unit receives a plurality of input signals containing values of a plurality of process parameters, generated by a plurality of devices and transmitted using the scheduled periodic communications, wherein the storage unit stores at least one value of each of the plurality of process parameters, and wherein the request signals request at least one stored value of at least one of the plurality of process parameters.

20. A viewing process function module according to claim 18, wherein the input signals generated by the first one of the devices are sent to a plurality of devices using the scheduled periodic communications.

21. A viewing process function module according to claim 18, wherein the storage unit stores information associated with the at least one process parameter.

22. A viewing process function module according to claim 18, wherein the viewing process function module is a viewing function block in a Fieldbus protocol.

23. A viewing process function module according to claim 18, wherein the second one of the devices is the process control device in which the viewing process function module is implemented.

24. A viewing process function module capable of being implemented in a process control device and of being used in a process control network having a plurality of devices communicatively coupled to a bus, wherein each of the devices includes one or more process function modules capable of performing an input function, an output function, or a control function within the process control network and capable of communicating on the bus using scheduled periodic communications, the viewing process function module comprising:

a data capture unit that receives a plurality of input signals containing values of at least one process parameter, the input signals generated by a plurality of the process function modules in one or more devices and transmitted using the scheduled periodic communications;

a storage unit that stores at least one value of each of the at least one process parameter without using the at least one value to perform process control; and

a data transfer unit that one of overwrites and appends the stored values of the at least one process parameter in the storage unit with the values of the at least one process parameter from the input signals.

25. A viewing process function module according to claim 24, wherein the input signals generated by the first one of the devices are sent to a plurality of devices using the scheduled periodic communications.

26. A viewing process function module according to claim 24, wherein the storage unit stores information associated with the at least one process parameter.

27. A viewing process function module according to claim 24, wherein the viewing process function module is a viewing function block in a Fieldbus protocol.

28. A viewing process function module according to claim 24, wherein each of the devices is capable of communicating on the bus using unscheduled queued communications, the viewing process function module further comprising:

an output host interface that receives request signals containing requests for at least one stored value of at least one process parameter requested by a user from a plurality of selectable process parameters, the request signals generated by at least one of the devices and sent using the unscheduled queued communications, and that transfers the request signals to the data transfer unit;

wherein the data transfer unit retrieves the at least one stored value of the at least one process parameter from the storage unit and transfers the at least one stored value to the output host interface; and

wherein the output host interface generates response signals containing the at least one value of the at least one process parameter and transmits the response signals to the requesting devices using the unscheduled queued communications.

29. A method of viewing real time process information in a process control network having a plurality of devices communicatively linked on a bus, wherein each of the devices includes at least one process function module capable of performing a process control function within the process control network using process parameters and capable of communicating on the bus, and a viewing bus monitor communicatively linked on the bus capable of filtering process data out of transmissions on the bus, of storing values of process parameters, of being configured by a user to store at least one process parameter, and of retrieving values of the process parameters in response to a request generated by a user selecting the process parameters from a plurality of selectable process parameters, the method comprising the steps of:

configuring the viewing bus monitor to store at least one value of at least one process parameter, each of the at least one process parameter being associated with one of the process function modules;

transmitting a process data message containing a value of the at least one process parameter onto the bus;

capturing transactions on the bus at the viewing bus monitor;

identifying the process data message containing the value of the at least one process parameter at the viewing bus monitor; and

storing the value of the at least one process parameter in the viewing bus monitor.

30. A method of viewing real time process information in a process control network according to claim 29, wherein the at least one process parameter is a plurality of process parameters.

31. A method of viewing real time process information in a process control network according to claim 29, further comprising the steps of:

configuring the viewing bus monitor to store information associated with the at least one process parameter; and

transmitting the associated information in the process data message with the value of the at least one process parameter.

32. A method of viewing real time process information in a process control network according to claim 29, wherein the viewing bus monitor includes a human interface and the method further comprises the steps of:

entering a request for at least one stored value of the at least one process parameter at the human interface;

retrieving the at least one stored value of the at least one process parameter from the viewing bus monitor; and

displaying the at least one stored value of the at least one process parameter from the viewing bus monitor at the human interface.

33. A method of viewing real time process information in a process control network according to claim 29, further comprising the steps of:

connecting a human interface to the first device;

entering a request for at least one stored value of the at least one process parameter at the human interface;

retrieving the at least one stored value of the at least one process parameter from the storage unit; and

displaying the at least one stored value of the at least one process parameter from the storage unit at the human interface.

34. An information viewing system for viewing real time values of process parameters in a process control network having a plurality of devices communicatively linked over a bus, wherein each of the devices is capable of performing a process function and of communicating on the bus, the information viewing system comprising:

a first signal generator disposed in a first device that generates process data messages including values of at least one process parameter;

a first communicator coupled to the first signal generator and configured to transmit the process data messages on the bus;

a data capture unit disposed in a viewing bus monitor that identifies the process data messages, wherein the viewing bus monitor is capable of capturing all transactions on the bus;

a storage unit disposed in the viewing bus monitor and communicatively linked to the data capture unit, the storage unit adapted to store at least one value of at least one process parameter without using the value to perform process control;

a human interface that generates requests for at least one value of the at least one process parameter contained in the storage unit, wherein the requests are generated by a user selecting the at least one process parameter from a plurality of selectable process parameters;

wherein the at least one value of the at least one process parameter is retrieved from the storage unit and displayed at the human interface.

35. An information viewing system according to claim 34, further comprising a data transfer unit disposed in the viewing bus monitor and communicatively linked to the data capture unit and the storage unit, wherein the data transfer unit is adapted to receive the value of the at least one process parameter from the data capture unit and to cause the storage unit to one of overwrite and append the stored value of the at least one process parameter with the value of the at least one process parameter transmitted in the corresponding process data message.

36. An information viewing system according to claim 35, wherein the data transfer unit is adapted to configure the storage unit to store one value of at least one process parameter, and the human interface is communicatively linked to the data transfer unit and adapted to transfer a process parameter configuration instruction to the data transfer unit, whereby the process parameter configuration instruction causes the data transfer unit to configure the storage unit to store at least one value of the at least one process parameter.

37. An information viewing system according to claim 34, wherein the human interface is disposed within the viewing bus monitor.

38. An information viewing system according to claim 34, wherein the at least one process parameter is a plurality of process parameters and the information viewing system further comprises a plurality of first devices each having a first signal generator disposed therein that generates process data messages including values of a process parameter associated with the first device, wherein the data capture unit captures each of the process data messages and the storage unit one of overwrites and appends a stored value of a process parameter with the value of the process parameter transmitted in the corresponding process data message by the associated first device.

39. An information viewing system according to claim 34, wherein the process data message includes information associated with the process parameter and the storage unit overwrites a stored value of the associated information stored therein with the value of the associated information in the process data message.

40. A viewing bus monitor capable of being used in a process control network having a plurality of devices communicatively coupled to a bus, wherein each of the devices includes at least one process function module capable of performing an input function, an output function, or a control function within the process control network and capable of communicating on the bus, and wherein a human interface is communicatively linked to the viewing bus monitor, the viewing bus monitor comprising:

a data capture unit adapted to capture all transactions on the bus and identify process data messages containing values of process parameters to be monitored by the viewing bus monitor, the process data messages generated by at least one of the devices and transmitted on the bus;

a storage unit configured to store at least one value of at least one process parameter without using the at least one value to perform process control;

a data transfer unit that causes the values of the at least one process parameter to be stored in the storage unit;

wherein the data transfer unit receives requests for at least one stored value of the at least one process parameter from the human interface; and

wherein the data transfer unit retrieves the at least one stored value of the at least one process parameter from the storage unit and transfers the at least one stored value to the human interface for display in response to the request.

41. A viewing bus monitor according to claim 40, wherein the data capture unit receives a plurality of process data messages containing values of a plurality of process parameters generated by a plurality of devices and transmitted on the bus, wherein the storage unit stores at least one value of each of the plurality of process parameters, and wherein each request may contain a request for at least one stored value of at least one of the plurality of process parameters.

42. A viewing bus monitor according to claim 40, wherein the storage unit stores information associated with the at least one process parameter.

43. A viewing bus monitor according to claim 40, wherein the human interface is disposed within the viewing bus monitor.

44. A viewing bus monitor according to claim 40, wherein the at least one process parameter is a plurality of process parameters.