Wireless gateway in a process control environment supporting a wireless communication protocol

• US 8,451,809 B2
• Filed: 04/10/2008
• Issued: 05/28/2013
• 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:
  US12/101,037
• Publication Number:
  US 20090010233A1
• Time in Patent Office: 1,874 Days
• Field of Search: None
• US Class Current: 370/338
• 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 wireless gateway for use in a process control environment includes a wireless interface for communicating with a first wireless network using a first wireless communication protocol, such that the wireless network includes a plurality of field devices operating in the process control environment. The wireless gateway further includes a host interface for communicating with an external host disposed outside the wireless network using a second communication protocol and a protocol translator to enable an exchange of data between the first interface and the second interface.

Claims

1. A wireless gateway for use in a process control environment, the wireless gateway comprising:

a wireless interface for communicating with a first wireless network using a first communication protocol,

wherein;

the first communication protocol is a wireless protocol having a first addressing scheme that is backwards compatible with a second addressing scheme of a second communication protocol,

the first addressing scheme and the second addressing scheme share at least one address field, and

the first addressing scheme includes an additional address field excluded from the second addressing scheme, and

wherein the wireless network includes a plurality of field devices operating in the process control environment, wherein each field device of the plurality of field devices corresponds to a physical function of a process controlled by the process control environment, and wherein the each field device generates process data corresponding to the physical function at a respective update rate stored at the each field device and transmits the generated process data using the first communication protocol;

a host interface for communicating with an external host disposed outside the wireless network using the second communication protocol, the second communication protocol being a wired communication protocol; and

a protocol translator to enable an exchange of data between the wireless interface and the host interface,

wherein the first communication protocol and the second communication protocol include a common application layer and distinct physical layers,

wherein the common application layer is layered over the respective physical layers of each of the first communication protocol having the first addressing scheme including the at least one address field and the second communication protocol having the second addressing scheme including the at least one address field and excluding the additional address field, and

wherein the common application layer defines a common set of commands and device types used in each of the first communication protocol and the second communication protocol to communicate the process data generated by the each field device.

2. The wireless gateway of claim 1, wherein the external host is associated with a plant automation network operating in the process control environment.

3. The wireless gateway of claim 1, wherein the common application layer is associated with a Highway Addressable Remote Transducer (HART®

) standard.

4. The wireless gateway of claim 1, wherein the wireless gateway includes a first physical device housing at least the host interface;

wherein the wireless interface includes a first wireless access point disposed in a second physical device having a wired connection with the first physical device.

5. The wireless gateway of claim 4, wherein the wireless interface further includes a second wireless access point disposed in a third physical device having a wired connection with the first physical device;

and wherein each of the first wireless access point and the second wireless access point has a substantially unique address within the wireless communication network.

6. The wireless gateway of claim 1, wherein the each field device of the plurality of field devices is associated with a substantially unique address consistent with the first addressing scheme of the wireless network;

wherein the external host is associated with a second network using the second addressing scheme; and

the wireless gateway further comprising;

an address converter for converting an address consistent with the second addressing scheme to an address consistent with the first addressing scheme to allow the external host to communicate with the each field device of the plurality of field devices using the second addressing scheme.

7. The wireless gateway of claim 1, further comprising a clocking source to provide synchronization to the wireless network.

8. The wireless gateway of claim 1, further comprising a network manager module responsible for managing routing and scheduling in the wireless network.

9. The wireless gateway of claim 1, wherein the host interface is one of a serial connection or an Ethernet connection.

10. The wireless gateway of claim 1, wherein the wireless gateway is adapted to adjust communication bandwidth on the wireless interface in response to detecting a change in communication requirements on the host interface.

11. The wireless gateway of claim 1, wherein the wireless gateway is a PC Card compatible with an expansion slot of a computer.

12. The wireless gateway of claim 1, wherein the wireless gateway is a component of an IO subsystem of one of a Programmable Logic Controller (PLC) system or a Distributed Control System (DCS).

13. The wireless gateway of claim 1, wherein the host interface is adapted to communicate with a Field Termination Assembly (FTA).

14. The wireless gateway of claim 1, further comprising:

a memory cache to store process data associated with at least some of the plurality of field devices;

wherein the wireless gateway receives the process data generated by the at least some of the plurality of field devices and transmits the process data generated by the at least some of the plurality of field devices to the external host in response to a command from the external host.

15. A combined communication network operating in a process control environment, the network comprising:

a first plurality of wireless field devices defining a first multi-node mesh communication network, wherein each of the first plurality of wireless field devices communicates with at least another one of first plurality of wireless field devices using a first wireless communication protocol, wherein each wireless field device of the first plurality of wireless field devices corresponds to a physical function of a process controlled by the process control environment, and wherein the each wireless field device generates process data, via the first wireless communication protocol, corresponding to the physical function at a respective update rate stored at the each wireless field device;

a second plurality of devices defining a second communication network using a second wired communication protocol; and

a first wireless gateway associated with the first communication network and providing protocol and address translation to at least the first plurality of wireless field devices to operatively connect the first multi-node mesh communication network to the second communication network;

wherein;

a first addressing scheme of the first wireless communication protocol is backwards compatible with a second addressing scheme of the second wired communication protocol, the first addressing scheme and the second addressing scheme sharing at least one address field, and the first addressing scheme including an additional address field excluded from the second addressing scheme,

the first wireless communication protocol and the second wired communication protocol include a common application layer and distinct physical layers, wherein the common application layer is layered over the respective physical layers of each of the first wireless communication protocol including the first addressing scheme including the at least one address field and the second wired communication protocol including the second addressing scheme including the at least one address field and excluding the additional address field, and

the common application layer defines a common set of command and device types used in each of the first wireless communication protocol and the second wired communication protocol to communicate the process data generated by the each wireless field device.

16. The combined communication network of claim 15, further comprising a third plurality of wireless field devices defining a second multi-node mesh communication network, the combined communication network further comprising a second wireless gateway associated with the second multi-node mesh communication network and operatively coupled to the first gateway device.

17. The combined communication network of claim 15, wherein the second plurality of devices includes at least several 4-20 mA devices;

wherein the combined communication network of claim 17 further comprises a Field Termination Assembly (FTA) coupled to the at least several 4-20 mA devices; and

wherein the first wireless gateway is coupled to at least one of the first plurality of wireless field devices via a first wireless interface and to the FTA via a second wired interface.

18. A wireless gateway for use in a process control environment having a plurality of wireless field devices defining a wireless mesh network, the wireless gateway comprising:

a plurality of network access points each including;

a wireless interface to communicate with at least one of the plurality of wireless field devices, wherein each wireless field device of the plurality of wireless field devices corresponds to a physical function of a process controlled by the process control environment, and wherein the each wireless field device generates process data corresponding to the physical function at a respective update rate stored at the each wireless field device; and

a host interface to communicate with an external host disposed outside the wireless mesh network; and

a virtual gateway communicatively coupled to each of the plurality of network access points in a wired manner,

the virtual gateway including a protocol translator for translating between a first wired protocol corresponding to the external host and a second wireless protocol corresponding to at least some of the plurality of wireless field devices,

the second wireless protocol having a second addressing scheme that is backwards compatible with a first addressing scheme of the first wired protocol, wherein the first addressing scheme and the second addressing scheme share at least one common address field, and the second addressing scheme includes an additional address field excluded from the first addressing scheme,

the first wired protocol and the second wireless protocol sharing a common application layer including a common set of commands and device types for communicating the process data generated by the each wireless field device, and

the translating between the first wired protocol and the second wireless protocol including translating between layers of the first wired protocol and layers of the second wireless protocol other than the common application layer.

19. The wireless gateway of claim 18, wherein the external host operates in a plant automation network associated with the process control environment;

and

wherein the host interface is a wired interface.

20. The wireless gateway of claim 18, wherein the virtual gateway is a software module operating in an external network including the external host.

21. The wireless gateway of claim 18, further comprising a secure interface to a network manager module responsible for managing the wireless mesh network.

22. The wireless gateway of claim 18, wherein exactly one wireless gateway is associated with the wireless mesh network;

wherein the virtual gateway operates outside the wireless mesh network; and

wherein the virtual gateway and each of the plurality of network access points has a unique address associated within the wireless mesh network.

23. The wireless gateway of claim 22, wherein each of the plurality of wireless field devices includes a memory unit storing the unique address of the virtual gateway.

24. The wireless gateway of claim 18, wherein each of the plurality of network access points is independent from every other one of the plurality of network access points;

and wherein each of the plurality of network access points is linked to each of the plurality of wireless field devices via zero or more intermediate wireless field devices.

25. The wireless gateway of claim 18, wherein exactly one of the plurality of network access points provides clocking to the wireless mesh network.

26. The wireless gateway of claim 18, wherein the wireless mesh network includes a wireless adapter coupled to a plurality of wired devices;

and wherein the wireless gateway further comprises a table storing an address of each of the plurality of wired devices for tunneling data between each of the plurality of wired devices and the external host.

27. A method of communicating with a wireless mesh network including a plurality of field devices and operating in a process control environment, the method comprising:

communicatively coupling the plurality of field devices to a wireless gateway, having a first wireless interface, a second interface, and a memory cache, via the first wireless interface, wherein each field device of the plurality of field devices corresponds to a physical function of a process controlled by the process control environment, and wherein the each field device generates process data to the wireless gateway using a periodic update;

connecting an external host to the second interface of the wireless gateway;

receiving process data at the wireless gateway from one of the plurality of field devices, the process data received in a periodic update from the one of the plurality of field devices via a first wireless protocol;

storing the process data received from the one of the plurality of field devices in the memory cache of the wireless gateway; and

reporting, via a second wired protocol, the process data received from the one of the plurality of field devices to the external host in response to detecting a report condition,

wherein;

a first addressing scheme of the first wireless protocol and a second addressing scheme of the second wired protocol share at least one common address field and the first addressing scheme includes an additional address field excluded from the second addressing scheme, and

the first wireless protocol and the second wired protocol share a common application layer including a common set of commands and device types for communicating the process data generated by the plurality of field devices.

28. The method of claim 27, wherein reporting the process data to the external host in response to detecting the report condition includes reporting the process data received from the one of the plurality of field devices in response to receiving a data request from the external host.

29. The method of claim 27, wherein receiving the process data at the wireless gateway further includes updating a data availability indication associated with the one of the plurality of field devices to a first value;

wherein reporting the process data received from the one of the plurality of field devices to the external host includes updating the data availability indication associated with the one of the plurality of field devices to a second value; and

wherein detecting a report condition includes comparing the data availability indication to the first value.

30. The method of claim 27, wherein receiving the process data from the one of the plurality of field devices at the wireless gateway further includes:

generating a timestamp associated with a reception time of the process data received from the one of the plurality of field devices; and

storing the timestamp in the memory cache;

the method further comprising;

reporting the timestamp along with the process data received from the one of the plurality of field devices in response to detecting the report condition.

31. The method of claim 27, further comprising:

receiving a request for change notifications from the external host, wherein the request for change notifications specifies a subset of the plurality of plurality of field devices including the one of the plurality of field devices;

updating a notification request indication associated with the external host and stored in the memory cache; and

wherein

detecting a report condition includes checking the notification request indication associated with the external host.

32. The method of claim 31, wherein one of the plurality of field devices is a first one of the plurality of field devices, the subset further includes a second one of the plurality of field devices and the method further comprises receiving data at the wireless gateway from the second one of the plurality of field devices.

33. The method of claim 27, wherein the process data is at least one of alarm or alert data corresponding to the one of the plurality of field devices;

wherein receiving the process data includes sending an acknowledgement corresponding to the alarm or alert data from the wireless gateway to the one of the plurality of field devices; and

wherein reporting the process data to the external host is not associated with an acknowledgement from the external host.

34. The method of claim 27, wherein detecting the report condition includes receiving a request for the process data from the external host or detecting a pre-established condition with respect to the process data.