Wireless Gateway in a Process Control Environment Supporting a Wireless Communication Protocol

• US 20090010233A1
• Filed: 04/10/2008
• Published: 01/08/2009
• Est. Priority Date: 04/13/2007
• Status: Active Grant

• Current Assignee: FieldComm Group, Inc.
• Original Assignee: Hart Communication Foundation (FieldComm Group, Inc.)
• Inventors: Nixon, Mark J., Rotvold, Eric D., Pratt, Wallace A. JR., Pramanik, Robin S., Lennvall, Tomas P.
• Granted Patent: US 8,451,809 B2
• Time in Patent Office: Days
• 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 and wherein the wireless network includes a plurality of field devices operating in the process control environment;

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.

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

and wherein the second communication protocol is a wired communication protocol.

3. The wireless gateway of claim 1, wherein the first communication protocol and the second communication protocol are associated with a shared application layer and distinct physical layers;

and wherein the shared application layer is layered over at least the respective physical layer of each of the first communication protocol and the second communication protocol.

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

) standard.

5. 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.

6. The wireless gateway of claim 5, 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.

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

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

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 each of the plurality of field devices using the second addressing scheme.

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

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

10. The wireless gateway of claim 1, wherein the second interface is one of a serial connection, an Ethernet, or Wi-Fi.

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

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

13. 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).

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

15. 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 from some of the plurality of field devices and transmits the process data to the external host in response to a command from the external host.

16. A combined communication network operating in a process control enviroment, 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 wireless communication protocol;

a second plurality of devices defining a second communication network using a second 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.

17. The combined communication network of claim 16, wherein the second plurality of devices is a 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.

18. The combined communication network of claim 16, 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 first wireless interface and to the FTA via a second wired interface.

19. 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; 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 commands between the external host and at least some of the plurality of wireless field devices.

20. The wireless gateway of claim 19, 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.

21. The wireless gateway of claim 19, wherein the virtual gateway is a software module operating in an external network including the external host.

22. The wireless gateway of claim 19, further comprising a secure interface to a network manager module responsible for managing the wireless mesh network.

23. The wireless gateway of claim 19, 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.

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

25. The wireless gateway of claim 19, 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 a zero or more intermediate wireless field devices.

26. The wireless gateway of claim 19, wherein exactly one of the plurality of network access points provides clocking to the wireless mesh network.

27. The wireless gateway of claim 19, 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.

28. 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;

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

receiving data at the wireless gateway from a first one of the plurality of field devices;

storing the data in the memory cache of the wireless gateway; and

reporting the data to the external host in response to detecting a report condition.

29. The method of claim 28, wherein the data is a process data associated with a process control function of the process control environment;

wherein receiving process data includes receiving a periodic update from the first one of the plurality of field devices; and

wherein reporting the process data to the external host in response to detecting a report condition includes reporting the process data in response to receiving a data request from the external host.

30. The method of claim 28, wherein receiving data at the wireless gateway further includes updating a data availability indication associated with the first one of the plurality of field devices to a first value;

wherein reporting the process control data 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.

31. The method of claim 28, wherein the data is a process data associated with a process control function of the process control environment;

and wherein receiving process data at the wireless gateway further includes;

generating a timestamp associated with a reception time of the process data; and

storing the timestamp in the memory cache;

the method further comprising;

reporting the timestamp associated with the process data along with the process data in response to detecting the report condition.

32. The method of claim 28, 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 first one of the plurality of field devices;

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

wherein

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

33. The method of claim 32, wherein the subset further includes a second one of the plurality of field devices;

the method further comprising;

receiving data at the wireless gateway from a first one of the plurality of field devices

34. The method of claim 28, wherein the data is at least one of alarm or alert data corresponding to the first one of the plurality of field devices;

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

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