Control of field device on low power wireless networks

• US 7,986,968 B2
• Filed: 01/11/2007
• Issued: 07/26/2011
• Est. Priority Date: 01/11/2006
• Status: Active Grant

• Current Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Original Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Inventors: Dobrowski, Patrick M., Orth, Kelly M., Lovegren, Eric R., Stotz, Kyle L., Karschnia, Robert
• Primary Examiner(s): Hu; Jinsong
• Assistant Examiner(s): TAYLOR, NATHAN SCOTT
• Application Number:
  US11/652,393
• Publication Number:
  US 20070161367A1
• Time in Patent Office: 1,657 Days
• Field of Search: 710/100, 455/410, 455/557, 370/392, 370/395.1, 370/401, 709/245
• US Class Current: 455/557
• CPC Class Codes: G05B 2219/31162 Wireless lan
• CPC Class Codes: H04L 41/00 Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 41/22 comprising specially adapted graphical user interfaces [GUI]
• CPC Class Codes: H04L 43/045 for graphical visualisation of monitoring data
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/28 in relation to timing considerations
• CPC Class Codes: H04L 47/34 ensuring sequence integrity, e.g. using sequence numbers
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 16/22 Traffic simulation tools or models
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 40/00 Communication routing or communication path finding
• CPC Class Codes: H04W 40/08 based on transmission power
• CPC Class Codes: H04W 40/10 based on available power or energy
• CPC Class Codes: H04W 40/22 using selective relaying for reaching a BTS [Base Transceiver Station] or an access point
• CPC Class Codes: H04W 40/24 : Connectivity information management, e.g. connectivity discovery or connectivity update
• CPC Class Codes: H04W 52/02 : Power saving arrangements in wired systems H04L12/12; signaling of mobile application services, e.g. low battery notifications H04W4/20
• CPC Class Codes: H04W 52/0225 : using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 52/0229 : where the received signal is a wanted signal
• CPC Class Codes: H04W 56/00 : Synchronisation arrangements
• CPC Class Codes: H04W 76/20 : Manipulation of established connections
• CPC Class Codes: H04W 8/04 : Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 8/26 : Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/00 : Wireless network protocols or protocol adaptations to wireless operation
• CPC Class Codes: H04W 84/18 : Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/16 : Gateway arrangements
• CPC Class Codes: H04W 92/00 : Interfaces specially adapted for wireless communication networks
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

A control system uses a wireless network to provide communication between a host computer and field devices. The host and the field devices communicate with one another using control messages and response messages based upon a known control system protocol. The control and response messages are embedded as a payload within a wireless message that is transmitted over the wireless network. When the wireless message is received at its ultimate destination, the control or response message is separated from the wireless message and is delivered to the intended recipient (either a field device or the host computer).

Claims

1. An industrial process control system comprising:

a host for providing control messages based upon a control system protocol;

a plurality of field devices for receiving control messages based upon the control system protocol, each of the plurality of field devices having a field device address;

a wireless mesh network for routing wireless messages between the host and the plurality of field devices based upon a wireless protocol, the wireless mesh network including;

a host interface for receiving a control message addressed to one of the plurality of field devices from the host according to the control system protocol, wherein the host interface produces a payload that includes the control message and the field device address, selects from a look-up table a wireless address according to the wireless protocol based on the field device address, and embeds the payload within a wireless message that includes the selected wireless address; and

a plurality of wireless nodes connected to communicate wireless messages through the wireless mesh network, at least one wireless node associated with two or more field devices, the wireless node having a field device interface and a corresponding wireless address, wherein a wireless message is communicated through the plurality of wireless nodes to the wireless node corresponding to the selected wireless address, wherein the field device interface associated with the addressed wireless node separates the control message from the wireless message and delivers the control message according to the control system protocol to the addressed field device as provided by the field device address included in the payload.

2. The system of claim 1, wherein the field device generates a response message, based upon the control system protocol, in response to a control message received from the host.

3. The system of claim 2, wherein the field device interface embeds the response message as a payload of a wireless response message to the host.

4. The system of claim 3, wherein the host interface receives the wireless response message, separates the response message from the wireless response message, and delivers the response message to the host.

5. The system of claim 1, wherein the host interface comprises a gateway of the wireless network.

6. The industrial process control system of claim 1, wherein the addressed wireless node turns On the addressed field device and after the field device is On delivers the control message according to the control system protocol to the addressed field device.

7. An industrial process control system comprising:

a plurality of field devices each having a field device address provided according to a control system protocol;

a host for sending control messages to field devices and receiving response messages from the field devices according to the control system protocol; and

a wireless mesh network for routing wireless messages among a plurality of nodes, each node being defined by a wireless address provided according to a wireless protocol and being associated with at least one of the plurality of field devices,

a gateway connected to receive a control message from the host according to a control system protocol that includes a field device address, wherein in response to a control message received from the host the gateway generates a wireless message having a wireless address selected from a lookup table based on the address of the selected field device and having a payload that includes an embedded control message and the address of a selected field device provided according to the control system protocol; and

wherein the wireless message is communicated through the wireless mesh network to the node corresponding to the wireless address of the wireless message, wherein the node separates the control message from the wireless message and delivers the control message to the addressed field device according to the control system protocol.

8. The system of claim 7, wherein the control messages and response messages are in a first protocol and the wireless messages are in a second protocol.

9. The system of claim 8, wherein the field device generates a response message, based upon a control system protocol, in response to a control message received from the host.

10. The system of claim 9, wherein the response message is embedded as a payload of a wireless response message to the host.

11. The system of claim 10, wherein the response message is separated from the wireless response message and delivered to the host.

12. The industrial process control system of claim 7, wherein the node corresponding to the wireless address of the wireless message turns On the addressed field device and after the field device is On delivers the control message to the addressed field device according to the control system protocol.

13. A method of communicating between a host and field devices of an industrial process control system over a wireless network comprised of a plurality of wireless nodes, the method comprising:

generating at the host a control message that includes a field device address provided according to a control system protocol of the field device to which the control message is directed;

removing physical layer overhead from the control message;

embedding a remaining portion of the control message as a payload of a wireless message;

selecting a wireless address from a lookup table based on the field device address and including the wireless address in the wireless message, wherein the wireless address is provided according to a wireless protocol;

transmitting the wireless message over the wireless network;

receiving the wireless message at one of the plurality of wireless nodes;

extracting the control message from the wireless message if the wireless message is addressed to the wireless node; and

delivering the control message to a field device to which it is addressed.

14. The method of claim 13 and further comprising:

generating a response message at the field device;

embedding the response message as a payload of a wireless message;

transmitting the wireless message with the embedded response message over the wireless network;

receiving the wireless message with the embedded response message;

extracting the response message from the wireless message; and

delivering the response message to the host.

15. The method of claim 14 wherein the control message and the response message are formatted in a control system protocol.

16. The method of claim 13, further including:

turning On the field device addressed in the control message prior to delivering the control message to the addressed field device.