Support for network management and device communications in a wireless network

• US 8,942,219 B2
• Filed: 04/10/2008
• Issued: 01/27/2015
• Est. Priority Date: 04/13/2007
• Status: Active Grant

• Current Assignee: FieldComm Group, Inc.
• Original Assignee: Hart Communication Foundation (FieldComm Group, Inc.)
• Inventors: Pratt, Wallace A. Jr., Nixon, Mark J., Rotvold, Eric D., Pramanik, Robin S., Lennvall, Tomas P.
• Primary Examiner(s): Harper, Kevin C
• Assistant Examiner(s): CHOUDHRY, SAMINA F
• Application Number:
  US12/101,049
• Publication Number:
  US 20090010204A1
• Time in Patent Office: 2,483 Days
• Field of Search: None
• US Class Current: 370/345
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 56/002 Mutual synchronization
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation

Abstract

A method of efficiently operating a wireless communication network in a process control environment, such that the wireless communication network includes a plurality of field devices, includes defining a communication protocol for supporting wireless communications between pairs of the plurality of field devices, including providing a set of protocol commands, transferring process control data from at least some of the plurality of field devices using a first subset of the set of protocol commands of the communication protocol, and transferring network management data to at least some of the plurality of field devices using a second subset of the set of protocol commands of the communication protocol.

Claims

1. A method of efficiently operating a wireless communication network in a process control environment, wherein the wireless communication network includes a plurality of field devices, the method comprising:

defining a communication protocol for supporting wireless communications between pairs of the plurality of field devices, including providing a set of protocol commands;

defining a plurality of concurrent overlapping superframes as repeating cycles of consecutively scheduled communication timeslots of a certain duration, wherein at least two of the plurality of concurrent overlapping superframes each includes a different number of communication timeslots, and wherein defining the plurality of concurrent overlapping superframes includes;

associating a first one of the plurality of concurrent superframes with network management data, wherein the first one of the plurality of concurrent superframes has a first number of communication timeslots and each of the plurality of field devices receives the network management data in at least one of the communication timeslots of the first one of the plurality of concurrent superframes;

associating a second one of the plurality of concurrent superframes with an update of a first field device, wherein the first field device originates respective process data within one of the communication timeslots of the second one of the plurality of concurrent superframes, and wherein a number of timeslots in the second one of the plurality of concurrent superframes corresponds to the update rate of the first field device; and

associating a third one of the plurality of concurrent superframes with an update of a second field device, wherein the second field device originates respective process data within one of the communication timeslots of the third one of the plurality of concurrent superframes, and wherein a number of timeslots in the third one of the plurality of concurrent superframes corresponds to the update rate of the second field device;

transferring process control data from the first field device of the plurality of field devices to at least the second field device of the plurality of field devices using a first subset of two or more of the set of protocol commands of the communication protocol, including transmitting and receiving data within the communication timeslots associated with the plurality of concurrent overlapping superframes, wherein the transferred process control data includes sensor measurement data and control data for controlling a particular device associated with a process control scheme; and

transferring the network management data from the first field device to the at least the second field device or to a third field device of the plurality of field devices using a second subset of two or more of the set of protocol commands of the communication protocol, including transmitting and receiving the network management data within the communication timeslots associated with the first one of the plurality of concurrent overlapping superframes.

2. The method of claim 1, wherein providing the set of protocol commands includes providing at least some commands of the Highway Addressable Remote Transducer (HART®

) communication protocol.

3. The method of claim 1, further comprising:

transferring alert or event data from the first field device to at least some of the plurality of field devices using a third subset of the set of protocol commands of the communication protocol.

4. The method of claim 1, wherein transferring the network management data includes associating the network management data with a first level of priority;

and wherein transferring the process control data includes associating the process control data with a second priority.

5. The method of claim 1, further comprising:

establishing a plurality of direct wireless connections between pairs of the plurality of field devices;

generating a plurality of directed graphs defining communication paths between pairs of the plurality of field devices based on a topology of the wireless network, wherein each directed graph includes at least one of the plurality direct connections;

associating one of the plurality of directed graphs with the network management data; and

associating another of the plurality of directed graphs with the process control data.

6. The method of claim 1, wherein transferring the process control data further includes transferring the process control data to a gateway device communicatively coupled to a plant automation network;

and wherein transferring the network management data further includes transferring the network management data to a network manager responsible for at least one of a scheduling scheme and a routing scheme in the wireless communication network.

7. The method of claim 1, further comprising tunneling data associated with another communication protocol using a tunneling subset of the set of protocol commands.

21. The method of claim 1, wherein transferring the process control data includes transferring an alarm from one of the plurality of field devices.

22. The method of claim 21, wherein transferring the alarm includes:

transmitting the alarm from the one of the plurality of field devices to a gateway connecting the wireless communication network to an external network;

retaining the alarm at the one of the plurality of field devices; and

discarding the alarm in response to receiving a confirmation from the gateway.

24. The method of claim 1, wherein the first subset of protocol commands and the second subset of protocol commands are associated with a single layer of a protocol stack of the communication protocol.

25. The method of claim 1, wherein supporting the wireless communications between the plurality of field devices includes using at least three or more superframes, each superframe being made up of a set of consecutively scheduled communication timeslots, each communication timeslot having the same duration;

and wherein transferring the process control data includes creating a message having a respective indicator identifying a particular process control command enclosing the process control data.

26. The method of claim 1, wherein providing the set of protocol commands includes providing commands to create and destroy superframes.

8. A method of transferring data in a wireless mesh communication network, the wireless mesh communication network including a plurality of wireless field devices and operating in a process control environment, and the method comprising:

generating, by a network manager computing device in communicative connection with the wireless mesh communication network, a communication schedule for the wireless mesh communication network, including;

defining, by the network manager computing device, a plurality of three or more concurrent overlapping superframes as repeating cycles of a number of consecutively scheduled communication timeslots, wherein each of the consecutively scheduled communication timeslots is of a certain duration and at least two of the plurality of concurrent overlapping superframes each includes a different number of communication timeslots;

associating, by the network manager computing device, a first one of the plurality of concurrent superframes with network management data, wherein the first one of the plurality of concurrent superframes has a first number of communication timeslots and each of the plurality of field devices receives the network management data in at least one of the communication timeslots of the first one of the plurality of concurrent superframes; and

associating, by the network manager computing device, a subset of the plurality of concurrent superframes including second and third ones of the plurality of concurrent superframes with process control data, wherein the subset does not include the first one of the plurality of concurrent superframes, and wherein process control data includes measurement data generated at one or more of the plurality of wireless field devices and control signals to control an operation of one or more of the plurality of wireless field devices as a part of a respective process control scheme, including;

associating, by the network manager computing device, the second one of the plurality of concurrent superframes with an update of a first field device, wherein the first field device originates respective process data within one of the communication timeslots of the second one of the plurality of concurrent superframes, and wherein a number of communication timeslots in the second one of the plurality of concurrent superframes corresponds to an update rate of the first field device; and

associating, by the network manager computing device, the third one of the plurality of concurrent superframes with an update of a second field device, wherein the second field device originates respective process data within one of the communication timeslots of the third one of the plurality of concurrent superframes, and wherein a number of communication timeslots in the third one of the plurality of concurrent superframes corresponds to an update rate of the second field device;

scheduling communications, by the network manager computing device, of each of the plurality of wireless field devices within communication timeslots associated with the plurality of concurrent superframes, the communications corresponding to transmitting and receiving respective process control data originating from each of the plurality of wireless field devices within the communication timeslots associated with the plurality of concurrent overlapping superframes, and transmitting and receiving network management data within the communication timeslots associated with the first one of the plurality of concurrent overlapping superframes; and

causing, by the network manager computing device, the respective scheduled communications of the each of the plurality of wireless field devices to be transmitted via the wireless mesh communication network to the each of the plurality of wireless field devices.

9. The method of claim 8, wherein associating, by the network manager computing device, the first one of the plurality of concurrent superframes with the network management data includes associating, by the network manager computing device, the first one of the plurality of concurrent superframes with data related to dynamic formation, configuration, and maintenance of the wireless mesh communication network;

wherein measurement data is associated with sensing or measurement functions; and

wherein control signals are associated with actuation or positioning functions.

10. The method of claim 8, wherein associating, by the network manager computing device, the subset of the plurality of concurrent superframes with process control data includes:

associating, by the network manager computing device, each superframe in the subset with a periodic update of a respective one of the plurality of wireless field devices;

wherein a number of communication timeslots in the superframe is proportional to a rate of the periodic update.

11. The method of claim 8, further comprising:

establishing, by the network manager computing device, a plurality of direct wireless connections between pairs of the plurality of wireless field devices;

generating, by the network manager computing device, a plurality of directed graphs defining communication paths from or to each of the plurality of field devices, wherein each directed graph includes at least one of the plurality of direct connections; and

associating, by the network manager computing device, a different scheduled communication timeslot with each one of the plurality of direct wireless connections associated with one or more of the plurality of directed graphs.

12. The method of claim 11, wherein generating, by the network manager computing device, the plurality of directed graphs includes:

exclusively associating, by the network manager computing device, a first one of the plurality of directed graphs with network management data; and

exclusively associating, by the network manager computing device, a second one of the plurality of directed graphs with process data.

13. The method of claim 8, further comprising:

associating, by the network manager computing device, the network management data with a first level of priority;

associating, by the network manager computing device, the process data with a second level of priority;

associating, by the network manager computing device, each of the plurality of wireless field devices with a priority mask including one or both of the first level of priority and the second level of priority; and

wherein

scheduling communications, by the network manager computing device, includes, at each of the plurality of wireless field devices;

scheduling communications, by the network manager computing device, to or from the wireless field device within one or more communication timeslots of the first one of the plurality of concurrent superframes only if a priority mask of the wireless field device includes the first level of priority.

14. The method of claim 13, further comprising:

dynamically updating, by the network manager computing device, a priority mask at one of the plurality of wireless field devices in response to detecting a change in the wireless mesh communication network.

15. The method of claim 8, wherein associating, by the network manager computing device, the first one of the plurality of concurrent superframes with the network management data includes associating the first one of the plurality of concurrent superframes with a length equal to an update rate of a slowest one of the plurality of wireless field devices;

wherein the length of the first one of the plurality of concurrent superframes corresponds to a number of communication timeslots.

16. A method of transferring data in a wireless mesh communication network including a plurality of wireless network devices and operating in a process control environment, the method comprising:

electronically generating, by a network manager in electronic communication with the wireless mesh communication network, a communication schedule for the wireless mesh communication network, including defining a plurality of concurrent overlapping superframes as repeating cycles of a number of consecutively scheduled communication timeslots of a fixed duration;

electronically generating, by the network manager, a plurality of directed graphs defining communication paths in a direction of one of toward or away from each of the plurality of network devices, wherein each directed graph includes at least one of a plurality direct connections between pairs of the plurality of network devices; and

electronically assigning, by the network manager, transmission opportunities to a plurality of communication timeslots, wherein each of the plurality of communication timeslots is scheduled within one of the plurality of concurrent overlapping superframes, wherein a first subset of the plurality of communication timeslots corresponding to the one of the plurality of concurrent overlapping superframes is associated with a first one of the plurality of directed graphs, and wherein a second subset of the plurality of communication timeslots corresponding to the one of the plurality of concurrent overlapping superframes is associated with a second one of the plurality of directed graphs, including;

associating, by the network manager, a first one of the plurality of communication timeslots with transmission of process data associated with a sensing or measurement function from a first network device of the plurality of network devices to a second network device of the plurality of network devices;

associating, by the network manager, a second one of the plurality of communication timeslots with transmission of process data associated with a positioning or actuating function from the first network device to the second network device or to a third network device of the plurality of network devices; and

associating, by the network manager, a third one of the plurality of communication timeslots with transmission of network management data from the first network device to the second network device, to the third network device, or to a fourth network device of the plurality of network devices.

17. The method of claim 16, wherein the plurality of wireless network devices includes a plurality of wireless field devices producing the process data.

18. The method of claim 16, wherein electronically assigning, by the network manager, the transmission opportunities to the plurality of communication timeslots includes electronically associating, by the network manager, each transmission opportunity with a command of a communication protocol supported by each of the plurality of network devices.

19. The method of claim 16, wherein electronically assigning, by the network manager, the transmission opportunities to the plurality of communication timeslots further comprises electronically associating, by the network manager, a fourth one of the plurality of communication timeslots with transmission of device management data.

20. The method of claim 19, wherein the device management data includes at least one of device diagnostic, device calibration, or device configuration data.

23. A method of transferring data in a wireless mesh communication network including a plurality of wireless network devices and operating in a process control environment, the method comprising:

generating a communication schedule for the wireless mesh communication network, including;

defining a plurality of concurrent overlapping superframes as repeating cycles of a number of consecutively scheduled communication timeslots of a fixed duration, wherein at least one of the plurality of superframes is associated with network management data and at least another one of the plurality of superframes is associated with process control data;

using a first one of a set of commands of a wireless communication protocol to transfer network management data;

using a second one of the set of wireless protocol commands of a communication protocol to transfer process control data;

wherein the wireless communication protocol shares at least one layer with a respective wired communication protocol;

generating a plurality of directed graphs defining communication paths in a direction of one of toward or away from each the plurality of network devices, wherein each directed graph includes at least one of a plurality direct connections between pairs of the plurality of network devices; and

assigning transmission opportunities to a plurality of communication timeslots, wherein each of the plurality of communication timeslots is scheduled within one of the plurality of concurrent overlapping superframes, wherein a first subset of the plurality of communication timeslots corresponding to the one of the plurality of concurrent overlapping superframes is associated with a first one of the plurality of directed graphs, and wherein a second subset of the plurality of communication timeslots corresponding to the one of the plurality of concurrent overlapping superframes is associated with a second one of the plurality of directed graphs.