Time stamped motion control network protocol that enables balanced single cycle timing and utilization of dynamic data structures

• US 7,983,769 B2
• Filed: 09/30/2005
• Issued: 07/19/2011
• Est. Priority Date: 11/23/2004
• Status: Active Grant

• Current Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Inventors: Westman, Donald A., Weinhofer, Juergen K., Keller, John M., Harris, Kendal R., Chaffee, Mark A.
• Primary Examiner(s): Decady; Albert
• Assistant Examiner(s): Lin; Jason
• Application Number:
  US11/241,539
• Publication Number:
  US 20060109376A1
• Time in Patent Office: 2,118 Days
• Field of Search: 700/29, 700/61, 700/86, 700/170, 700/182, 348/423.1, 348/700, 386/78, 703/19
• US Class Current: 700/29
• CPC Class Codes: G05B 19/0423 Input/output
• CPC Class Codes: G05B 19/408 characterised by data handling or data format, e.g. reading, buffering or conversion of data
• CPC Class Codes: G05B 19/4185 characterised by the network communication
• CPC Class Codes: G05B 2219/25472 Synchronise controllers, sensors, measurement with data bus
• CPC Class Codes: G05B 2219/33273 DCS distributed, decentralised controlsystem, multiprocessor
• CPC Class Codes: G05B 2219/34208 Motion controller
• CPC Class Codes: G05B 2219/34413 Add time stamp to command message
• CPC Class Codes: H04J 3/0664 unidirectional timestamps
• CPC Class Codes: H04J 3/067 Details of the timestamp structure
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A system that enables controlling motion over a network comprises an interface that receives motion control data that includes a time stamp from the network. Additionally, the system includes a motion control component that utilizes the received motion control data to update properties associated with the motion control component based at least in part on the time stamp. The system can also include a clock that is synchronized with disparate clocks associated with disparate motion control components located on the network.

Claims

1. A system that enables controlling motion over a network, comprising:

an interface that receives motion control data that includes a time stamp from the network during a connection cycle, the connection cycle includes a drive update period which is not an integer multiple of a controller update period (CUP); and

a motion control component that utilizes the received motion control data to update properties associated with the motion control component within the drive update period or the CUP, based at least in part on the time stamp.

2. The system of claim 1, the interface transmits disparate motion control data that includes a disparate time stamp to a disparate motion control component via the network.

3. The system of claim 1, the motion control component is a controller.

4. The system of claim 1, the motion control component is a control axis object.

5. The system of claim 1, the motion control component is a drive.

6. The system of claim 1, the motion control component is a drive axis object.

7. The system of claim 1, the motion control data is command data that is transmitted from a controller to a drive.

8. The system of claim 7, the time stamp associated with the command data relates to a time that modifications to the motion control component are effectuated.

9. The system of claim 1, the motion control data is actual data that is transmitted from a drive to a controller.

10. The system of claim 9, the time stamp associated with the actual data relates to a time that the actual data is measured.

11. The system of claim 1, the motion control component further comprises a clock that is synchronized with disparate clocks associated with disparate motion control components located on the network.

12. The system of claim 11, the clock is synchronized utilizing IEEE 1588 precision time protocol.

13. The system of claim 1, the motion control component modifies commands to conform to the motion control data at a time associated with the time stamp.

14. The system of claim 1, the motion control component analyzes the motion control data to generate commands that are to be utilized by a disparate motion control component.

15. The system of claim 1, the motion control component measures data, incorporates a time stamp associated with a current time that the data is measured, and transmits the data as motion control data to a disparate motion control component.

16. The system of claim 1, the motion control component further comprises a time stamp component that enables at least one of incorporating a time stamp into data that is generated for transfer over the network via the interface or evaluating the received motion control data to identify a time associated with the time stamp.

17. The system of claim 1, the motion control component further comprises a cycle timing component that identifies a particular interval of a motion control update cycle.

18. The system of claim 17, the cycle timing component identifies at least one of an input transfer interval during which motion control data is transferred from a drive to a controller, a calculation interval during which motion control data is not transferred via the network, or an output transfer interval during which motion control data is transferred from the controller to the drive.

19. The system of claim 18, wherein the interface at least one of transmits or receives non-motion related data via the network during the calculation interval.

20. The system of claim 1, the motion control component further comprises a dynamic data generator that produces data structures of at least one of varying size or varying content, and incorporates a description of the data structures into the data structures.

21. The system of claim 1, the motion control component further comprises a data format evaluator that determines at least one of a size or content associated with the motion control data that is associated with a dynamic data structure.

22. The system of claim 1, the motion control component further comprises a node population component that at least one of adds a node to the network or removes a node from the network during runtime.

23. The system of claim 1, further comprising a data adjustment component that at least one of interpolates or extrapolates the motion control data to a current time based at least in part upon the time stamp.

24. The system of claim 1, the motion control component is associated with an update period that is different from that of a disparate motion control component.

25. The system of claim 1, the network includes at least one of Ethernet, ControlNet, or DeviceNet.

26. A system that enables controlling motion in an industrial automation environment, comprising:

a controller that generates command data, which includes a time stamp associated with a time to effectuate modifications, during a controller update period (CUP) and transmits the command data over a network; and

a drive that receives the command data and modifies associated commands based on the command data at a time that corresponds with the time stamp, within a drive update period,

wherein the drive update period is not an integer multiple of the CUP.

27. The system of claim 26, the drive further measures actual data, includes a time stamp in the actual data associated with a time the measurement was taken, and transmits the actual data to the controller over the network.

28. The system of claim 27, the controller further generates the command data based at least in part on the actual data.

29. The system of claim 27, the actual data is at least one of actual primary position, actual secondary position, actual velocity, actual acceleration, actual torque, actual current, actual voltage, or actual frequency.

30. The system of claim 26, further comprising M additional controllers that communicate via the network, where M is a positive integer.

31. The system of claim 26, further comprising N additional drives that communicate via the network, where N is a positive integer.

32. The system of claim 26, the controller communicates with a disparate controller via a peer-to-peer connection.

33. The system of claim 26, the drive communicates with a disparate drive via a peer-to-peer connection.

34. A method that facilitates controlling motion over a network in an industrial automation environment, comprising:

incorporating a time stamp with motion related data;

transmitting the motion related data with the time stamp over a network, during a first update period, to a motion control component that employs a second update period, wherein the first update period is different from an integer multiple of the second update period;

receiving disparate motion related data with a disparate time stamp from the motion control component; and

updating a receiving node based on the disparate motion related data with the disparate time stamp.

35. The method of claim 34, further comprising identifying an interval during which to transmit the motion related data with the time stamp.

36. The method of claim 35, further comprising transmitting the motion related data from a drive to a controller when the identified interval is an input transfer interval.

37. The method of claim 35, further comprising transmitting the motion related data from a controller to a drive when the identified interval is an output transfer interval.

38. The method of claim 35, further comprising inhibiting transmission of motion related data when the identified interval is a calculation interval.

39. The method of claim 34, further comprising:

generating dynamic motion related data which has a time stamp included and is to be transmitted and received; and

determining a format of the dynamic motion related data with the time stamp to facilitate unpackaging the dynamic motion related data.

40. The method of claim 34, updating the receiving node comprises at least one of:

varying operation of a drive by modifying associated commands;

or

generating new commands via utilizing a controller.

41. The method of claim 34, further comprising synchronizing a clock with disparate nodes in the network.

42. The method of claim 34, further comprising at least one of:

adding a node after the network has been configured without reconfiguring the network;

or

removing a node after the network has been configured without reconfiguring the network.

43. The method of claim 34, further comprising prioritizing the motion related data with respect to non-motion related data transmitted via the network.

44. A method that enables controlling motion over a network, comprising:

receiving motion control data that includes a time stamp from the network from a component employing a first update period; and

employing the received motion control data to update properties associated with the motion control component based at least in part on the time stamp, within a second update period, wherein the first update period is disparate from an integer multiple of the second update period.