Multi-Protocol Bus Device

• US 20090070504A1
• Filed: 11/10/2008
• Published: 03/12/2009
• Est. Priority Date: 09/18/2001
• Status: Active Grant

• Current Assignee: Schneider Electric Systems USA, Inc. (Schneider Electric SE)
• Original Assignee: Invensys Systems Incorporated (Invensys PLC)
• Inventors: Kostadinov, Vladimir
• Granted Patent: US 8,161,200 B2
• Time in Patent Office: Days
• US Class Current: 710/105
• CPC Class Codes: H04L 12/40032 Details regarding a bus interface enhancer
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

In one general aspect, methods and devices for use with multiple communications protocols automatically determine which communications protocol to use when connected to a system bus. Signals transmitted on the system bus are monitored to determine what communications protocol the system bus is using. After determining which communications protocol the system is using, a compatible communications protocol is selected from one of several communications protocols stored in a device'"'"'s memory. As a result, a user may connect a device to the system bus without having to determine which communications protocol is used by the system bus. Furthermore, suppliers may stock a single type of device that is compatible with multiple communications protocols reducing overhead associated with stocking devices. In addition, a device may be switched between systems without regard to the communications protocol of the device or system.

Claims

1. A method implemented within an industrial control device for communicating on a bus, the method comprising:

monitoring signals transmitted on the bus;

determining that two or more monitored signals have a relationship;

selecting a communications protocol that corresponds to the relationship; and

processing signals according to the selected communications protocol.

2. The method of claim 1 wherein the relationship is that the two or more monitored signals form a sequence that is specific to a communications protocol.

3. The method of claim 2 wherein determining that two or more monitored signals have a relationship includes determining if the sequence formed by the two or more monitored signals matches a specific sequence of signals that corresponds to a communications protocol.

4. The method of claim 1 further comprising storing a specific sequence that corresponds to a communications protocol, wherein determining that two or more monitored signals have a relationship includes determining if the sequence of the two or more signals matches the stored specific sequence.

5. An industrial control device comprising:

a bus interface monitoring signals; and

a processor operable to determine that two or more monitored signals have a relationship, to select a communications protocol that corresponds to the relationship, and to process the signals according to the selected communications protocol.

6. The device of claim 5 wherein the relationship is that two or more signals form a sequence that is specific to a communications protocol.

7. The device of claim 5 wherein the processor determines that two or more monitored signals have a relationship if the sequence fonned by the two or more monitored signals matches a sequence of signals that is specific to a communications protocol.

8. The device of claim 5 further comprising a memory to store a sequence of signals that is specific to a communications protocol wherein the processor determines if a sequence formed by the two or more monitored signal matches the stored specific sequence and selects the communications protocol if a match is determined.