Method and apparatus to identify a communication protocol being used in a process control system

• US 9,984,022 B2
• Filed: 07/19/2016
• Issued: 05/29/2018
• Est. Priority Date: 05/07/2012
• Status: Active Grant

• Current Assignee: Bristol (Emerson Electric Company)
• Original Assignee: Bristol (Emerson Electric Company)
• Inventors: Liu, Xuedong
• Primary Examiner(s): Cleary, Thomas J
• Application Number:
  US15/214,387
• Publication Number:
  US 20160328352A1
• Time in Patent Office: 679 Days
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices
• CPC Class Codes: G06F 13/4063 Device-to-bus coupling
• CPC Class Codes: G06F 13/42 Bus transfer protocol, e.g. handshake; Synchronisation
• CPC Class Codes: G06F 13/4226 with asynchronous protocol
• CPC Class Codes: G06F 13/4286 using a handshaking protocol, e.g. RS232C link
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

Methods and apparatus to identify a communication protocol being used in a process control system are disclosed. An example apparatus includes a process control device including a port to be in communication with a bus, the process control device to receive a first signal at the port and a second signal at the port, the process control device including a protocol detector to compare the first signal to reference communication protocols to identify the first signal as being associated with a first communication protocol, the protocol detector to compare the second signal to the reference communication protocols to identify the second signal as being associated with a second communication protocol, the first communication protocol being different than the second communication protocol, the processor to process the first signal based on the first communication protocol and the second signal based on the second communication protocol.

Claims

1. An apparatus, comprising:

a process control device including a port to be in communication with a bus, the process control device to receive a first signal at the port, prior to the first signal being received, the process control device not being configured to process signals according to any of a plurality of process control message protocols, the process control device including a protocol detector to compare the first signal to reference communication protocols to identify the first signal as being associated with a first communication protocol of the plurality of process control message protocols, in response to the process control device processing the first signal based on the first communication protocol, the process control device to generate a first outgoing message based on the first communication protocol, the first outgoing message being different from the first signal, the process control device to receive a second signal at the port, in response to the second signal being received, the process control device not being configured to process signals according to any of the plurality of process control message protocols, the protocol detector to compare the second signal to the reference communication protocols to identify the second signal as being associated with a second communication protocol of the plurality of process control message protocols, the first communication protocol being different than the second communication protocol, the process control device to process the second signal based on the second communication protocol, in response to the process control device processing the second signal based on the second communication protocol, the process control device to generate a second outgoing message based on the second communication protocol, the second outgoing message being different from the second signal.

2. The apparatus of claim 1, wherein the first communication protocol corresponds to one of a Highway Addressable Remote Transducer protocol, a MODBUS protocol, or a Bristol Standard Asynchronous Protocol.

3. The apparatus of claim 1, wherein the protocol detector is to 1) automatically compare the first signal to the reference communication protocols;

and

     2) automatically compare the second signal to the reference communication protocols.

4. The apparatus of claim 1, wherein, in response to the protocol detector not determining a first or second communication protocol, the process control device entering an initial state in which the process control device is not configured to process signals according to any of the plurality of process control message protocols.

5. The apparatus of claim 1, wherein the protocol detector is to compare the first signal to the reference communication protocols by identifying a match between the first communication protocol and the first signal.

6. The apparatus of claim 1, wherein the protocol detector is to compare the first signal to the reference communication protocols by identifying a dissimilarity between the first signal and communication protocols other than the first communication protocol.

7. The apparatus of claim 1, wherein the protocol detector is to compare the first signal to the reference communication protocols by determining if the first signal includes one or more of:

1) between five and twenty preamble bytes, each preamble byte including a 0xff symbol when a message field corresponds to a preamble field;

     2) a delimiter byte when the message field corresponds to a delimiter field;

     3) a five-byte address when the message field corresponds to an address;

     4) a command byte when the message field corresponds to a command field;

     5) a single checksum byte when the message field corresponds to a checksum field;

     6) data associated with a start interval when the message field corresponds to a start interval;

     7) data associated with an end interval when the message field corresponds to an end interval;

     8) a function byte when the message field corresponds to a function field;

     9) two cyclical redundancy check bytes when the message field corresponds to a cyclical redundancy check field;

     10) a data link escape byte when the message field corresponds to a data link escape field;

     11) a start text byte when the message field corresponds to a start text field;

     12) seven header bytes when the message field corresponds to a seven-byte header field;

     13) twelve header bytes when the message field corresponds to a twelve-byte header field;

     14) a second data link escape byte when the message field corresponds to a second data link escape field;

     15) an end text byte when the message field corresponds to an end text field;

or

     16) two cyclical redundancy check bytes when the message field corresponds to a two-byte cyclical redundancy check field.

8. A method, comprising:

receiving a first signal at a port of a process control device, prior to the first signal being received, the process control device not being configured to process signals according to any of a plurality of process control message protocols;

comparing the first signal to reference communication protocols to identify the first signal as being associated with a first communication protocol;

processing the first signal based on the first communication protocol;

generating a first outgoing message based on the first communication protocol, the first outgoing message being different from the first signal;

receiving a second signal at the port;

in response to receiving the second signal, initializing the process control device wherein the process control device is not configured to process signals according to any of the plurality of process control message protocols;

comparing the second signal to the reference communication protocols to identify the second signal as being associated with a second communication protocol, the first communication protocol being different than the second communication protocol;

processing the second signal based on the second communication protocol; and

generating a second outgoing message based on the second communication protocol, the second outgoing message being different from the second signal.

9. The method of claim 8, wherein the first communication protocol corresponds to one of a Highway Addressable Remote Transducer protocol, a MODBUS protocol, or a Bristol Standard Asynchronous Protocol.

10. The method of claim 8, wherein comparing the first signal to the reference communication protocols includes automatically comparing the first signal to the reference communication protocols, and comparing the second signal to the reference communication protocols includes automatically comparing the first signal to the reference communication protocols.

11. The method of claim 8, wherein, in response to the protocol detector not detecting a first or second communication protocol, the process control device entering an initial state in which the process control device is not configured to process signals according to any of the plurality of process control message protocols.

12. The method of claim 8, wherein comparing the first signal to reference communication protocols includes identifying a match between the first communication protocol and the first signal.

13. The method of claim 8, wherein comparing the first signal to the reference communication protocols includes identifying a dissimilarity between the first signal and communication protocols other than the first communication protocol.

14. The method of claim 8, wherein comparing the first signal to the reference communication protocols includes determining if the first signal includes one or more of:

1) between five and twenty preamble bytes, each preamble byte including a 0xff symbol when a message field corresponds to a preamble field;

     2) a delimiter byte when the message field corresponds to a delimiter field;

     3) a five-byte address when the message field corresponds to an address;

     4) a command byte when the message field corresponds to a command field;

     5) a single checksum byte when the message field corresponds to a checksum field;

     6) data associated with a start interval when the message field corresponds to a start interval;

     7) data associated with an end interval when the message field corresponds to an end interval;

     8) a function byte when the message field corresponds to a function field;

     9) two cyclical redundancy check bytes when the message field corresponds to a cyclical redundancy check field;

     10) a data link escape byte when the message field corresponds to a data link escape field;

     11) a start text byte when the message field corresponds to a start text field;

     12) seven header bytes when the message field corresponds to a seven-byte header field;

     13) twelve header bytes when the message field corresponds to a twelve-byte header field;

     14) a second data link escape byte when the message field corresponds to a second data link escape field;

     15) an end text byte when the message field corresponds to an end text field;

or

     16) two cyclical redundancy check bytes when the message field corresponds to a two-byte cyclical redundancy check field.

15. A tangible computer readable storage medium comprising instructions which, when executed, cause a machine to at least:

compare a first signal to reference communication protocols to identify the first signal as being associated with a first communication protocol, the first signal received at a port of a process control device, prior to receiving the first signal, the process control device not being configured to process signals according to any of a plurality of process control message protocols;

process the first signal based on the first communication protocol;

generate a first outgoing message based on the first communication protocol, the first outgoing message being different from the first signal;

compare a second signal to the reference communication protocols to identify the second signal as being associated with a second communication protocol, immediately prior to receiving the second signal, the process control device not being configured to process signals according to any of the plurality of process control message protocols, the second signal received at the port, the first communication protocol being different than the second communication;

process the second signal based on the second communication protocol; and

generate a second outgoing message based on the second communication protocol, the second outgoing message being different from the second signal.

16. The tangible computer readable storage medium of claim 15, wherein the first communication protocol corresponds to one of a Highway Addressable Remote Transducer protocol, a MODBUS protocol, or a Bristol Standard Asynchronous Protocol.

17. The tangible computer readable storage medium of claim 15, wherein instructions cause the machine to 1) compare the first signal to the reference communication protocols by automatically comparing the first signal to the reference communication protocols and 2) compare the second signal to the reference communication protocols by automatically comparing the first signal to the reference communication protocols.

18. The tangible computer readable storage medium of claim 15, wherein the instructions cause the machine to, in response to the protocol detector not determining a first or second communication protocol, the process control device entering an initial state in which the process control device is not configured to process signals according to any of the plurality of process control message protocols.

19. The tangible computer readable storage medium of claim 15, wherein the instructions cause the machine to compare the first signal to reference communication protocols by identifying a match between the first communication protocol and the first signal.

20. The tangible computer readable storage medium of claim 15, wherein the instructions cause the machine to compare the first signal to reference communication protocols by identifying a dissimilarity between the first signal and communication protocols other than the first communication protocol.