METHODS AND APPARATUS TO IDENTIFY A COMMUNICATION PROTOCOL BEING USED IN A PROCESS CONTROL SYSTEM

• US 20130297842A1
• Filed: 05/06/2013
• Published: 11/07/2013
• Est. Priority Date: 05/07/2012
• Status: Active Grant

• Current Assignee: Bristol Inc (Emerson Electric Company)
• Original Assignee: Bristol Inc (Emerson Electric Company)
• Inventors: Liu, Xuedong
• Granted Patent: US 9,430,429 B2
• Time in Patent Office: Days
• US Class Current: 710/105
• 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 method includes determining a message structure of a process control message received via a port, determining that the message structure corresponds to a first one of a plurality of process control message protocols, and processing the process control message according to the first process control message protocol.

Claims

1. A method, comprising:

determining that the process control system message receiving via a port has a message structure corresponding to a first one of a plurality of process control message protocols; and

processing the process control message according to the first process control message protocol.

2. The method of claim 1, wherein the first one of the plurality of process control message protocols corresponds to one of a Highway Addressable Remote Transducer protocol, a MODBUS protocol, or a Bristol Standard Asynchronous Protocol.

3. The method of claim 1, further comprising:

;

parsing the process control message to identify a message field of the process control message;

matching the content of the message field to a known field of the message structure corresponding to the first one of the plurality of process control message protocols.

4. The method of claim 3, further comprising determining that the message structure corresponds to a Highway Addressable Remote Transducer protocol if the content of the message field comprises a five-twenty byte preamble of 0xff bytes when the known field corresponds to a preamble field.

5. The method of claim 3, further comprising determining that the message structure corresponds to a Highway Addressable Remote Transducer protocol if the content of the message field comprises a delimiter byte when the known field corresponds to a delimiter field.

6. The method of claim 3, further comprising determining that the message structure corresponds to a Highway Addressable Remote Transducer protocol if the content of the message field comprises a five-byte address when the known field corresponds to an address.

7. The method of claim 3, further comprising determining that the message structure corresponds to a Highway Addressable Remote Transducer protocol if the content of the message field comprises a command byte when the known field corresponds to a command field.

8. The method of claim 3, further comprising determining that the message structure corresponds to a Highway Addressable Remote Transducer protocol if the content of the message field comprises a single checksum byte when the known field corresponds to a checksum field.

9. The method of claim 3, further comprising determining that the message structure corresponds to a MODBUS protocol if the content of the message field comprises data associated with a start interval or an end interval when the known field corresponds to a start interval or an end interval.

10. The method of claim 3, further comprising determining that the message structure corresponds to a MODBUS protocol if the content of the message field comprises a function byte when the known field corresponds to a function field.

11. The method of claim 3, further comprising determining that the message structure corresponds to a Bristol Standard Asynchronous Protocol if the content of the message field comprises seven or twelve header bytes when the known field corresponds to a seven-byte or a twelve-byte header field.

12. The method of claim 3, further comprising determining that the message structure corresponds to a Bristol Standard Asynchronous Protocol if the content of the message field comprises a data link escape byte when the known field corresponds to a data link escape field.

13. The method of claim 12, further comprising determining that the message structure corresponds to a Bristol Standard Asynchronous Protocol if a second content of a second message field comprises a second data link escape byte when the known field corresponds to a second data link escape field.

14. The method of claim 3, further comprising determining that the message structure corresponds to a Bristol Standard Asynchronous Protocol if the content of the message field comprises a start text byte when the known field corresponds to a start text field.

15. The method of claim 3, further comprising determining that the message structure corresponds to a Bristol Standard Asynchronous Protocol if the content of the message field comprises an end text byte when the known field corresponds to an end text field.

16. The method of claim 3, further comprising determining that the message structure corresponds to one of a MODBUS protocol or a Bristol Standard Asynchronous Protocol if the content of the message field comprises two cyclical redundancy check bytes when the known field corresponds to a two-byte cyclical redundancy check field.

17. The method of claim 1, wherein the port is configured to communicate over one of an RS485 bus or a Frequency Shift Keying bus.

18. An apparatus comprising:

a port to receive a process control message;

a protocol detector to determine that the process control system message has a message structure corresponding to a first one of a plurality of process control message protocols; and

a processor to process the process control message according to the first process control message protocol.

19. The apparatus of claim 18, wherein the first one of the plurality of process control message protocols corresponds to one of a Highway Addressable Remote Transducer protocol, a MODBUS protocol, or a Bristol Standard Asynchronous Protocol.

20. The apparatus of claim 18, wherein the protocol detector is to determine that the message structure of the process control message corresponds to a Highway Addressable Remote Transducer protocol if the content of a message field of the process control message comprises at least one of:

a five-twenty byte preamble of 0xff bytes when the known field corresponds to a preamble field,

a delimiter byte when the known field corresponds to a delimiter field,

a five-byte address when the known field corresponds to an address,

a command byte when the known field corresponds to a command field, or

a single checksum byte when the known field corresponds to a checksum field.

21. The apparatus of claim 18, wherein the protocol detector is to determine that the message structure of the process control message corresponds to a MODBUS protocol if the content of a message field of the process control message comprises at least one of:

data associated with a start interval when the known field corresponds to a start interval,

data associated with an end interval when the known field corresponds to an end interval,

a function byte when the known field corresponds to a function field, or

two cyclical redundancy check bytes when the known field corresponds to a cyclical redundancy check field.

22. The apparatus of claim 18, wherein the protocol detector is to determine that the message structure of the process control message corresponds to a Bristol Standard Asynchronous Protocol if the content of a message field of the process control message comprises at least one of:

a data link escape byte when the known field corresponds to a data link escape field,

a start text byte when the known field corresponds to a start text field,

seven header bytes when the known field corresponds to a seven-byte header field,

twelve header bytes when the known field corresponds to a twelve-byte header field,

a second data link escape byte when the known field corresponds to a second data link escape field,

an end text byte when the known field corresponds to an end text field, or

two cyclical redundancy check bytes when the known field corresponds to a two-byte cyclical.

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

receiving a process control message via a port;

determining that the process control system message has a message structure corresponding to a first one of a plurality of process control message protocols; and

processing the process control message according to the first process control message protocol.

24. A storage medium as defined in claim 23, wherein the instructions are further to cause the machine to determine that the message structure corresponds to a Highway Addressable Remote Transducer protocol if the content of the message field of the process control message comprises at least one of:

a five-twenty byte preamble of 0xff bytes when the known field corresponds to a preamble field,

a delimiter byte when the known field corresponds to a delimiter field,

a five-byte address when the known field corresponds to an address,

a command byte when the known field corresponds to a command field, or

a single checksum byte when the known field corresponds to a checksum field.

25. A storage medium as defined in claim 23, wherein the instructions are further to cause the machine to determine that the message structure corresponds to a MODBUS protocol if the content of the message field of the process control message comprises at least one of:

data associated with a start interval when the known field corresponds to a start interval,

data associated with an end interval when the known field corresponds to an end interval,

a function byte when the known field corresponds to a function field, or two cyclical redundancy check bytes when the known field corresponds to a cyclical redundancy check field.

26. A storage medium as defined in claim 23, wherein the instructions are further to cause the machine to determine that the message structure corresponds to a Bristol Standard Asynchronous Protocol if the content of the message field of the process control message comprises at least one of:

a data link escape byte when the known field corresponds to a data link escape field,

a start text byte when the known field corresponds to a start text field, seven header bytes when the known field corresponds to a seven-byte header field,

twelve header bytes when the known field corresponds to a twelve-byte header field,

a second data link escape byte when the known field corresponds to a second data link escape field,

an end text byte when the known field corresponds to an end text field, or

two cyclical redundancy check bytes when the known field corresponds to a two-byte cyclical.

27. A storage medium as defined in claim 23, wherein the instructions are further to cause the machine to determine that the message structure corresponds to one of a MODBUS protocol or a Bristol Standard Asynchronous Protocol if the content of the message field comprises two cyclical redundancy check bytes when the known field corresponds to a two-byte cyclical redundancy check field.