PLC to PLC communications with a modem on the PLC I/O bus

• US 7,124,206 B2
• Filed: 10/16/2002
• Issued: 10/17/2006
• Est. Priority Date: 12/18/2001
• Status: Active Grant

• Current Assignee: Siemens Industry Incorporated (Siemens AG)
• Original Assignee: Siemens Energy & Automation Incorporated (Siemens AG)
• Inventors: Hausman, Steven Michael
• Primary Examiner(s): Maung, Zarni
• Assistant Examiner(s): Madamba, Glenford J.
• Application Number:
  US10/271,921
• Publication Number:
  US 20030188033A1
• Time in Patent Office: 1,462 Days
• Field of Search: 709/250, 710/11
• US Class Current: 709/250
• CPC Class Codes: G05B 19/00 Programme-control systems
• CPC Class Codes: G05B 19/05 Programmable logic controllers, e.g. simulating logic interconnections of signals according to ladder diagrams or function charts
• CPC Class Codes: G05B 19/054 Input/output
• CPC Class Codes: G05B 2219/15018 Communication, serial data transmission, modem
• CPC Class Codes: G05B 2219/15078 Modules, construction of system
• CPC Class Codes: H04M 11/06 Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors

Abstract

At least one exemplary embodiment of the present invention includes a system comprising a first modem integral to a first programmable logic controller, and a second modem integral to a second programmable logic controller, the first modem adapted to communicate with the second modem via a communications network. At least one exemplary embodiment of the present invention includes a method comprising coupling a first modem to a second modem, the first modem integral to a first programmable logic controller, the second modem connected to a second programmable logic controller, and transferring data between the first modem and the second modem. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. This abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Claims

1. A system, comprising:

a first programmable logic controller;

a first modem integral to said first programmable logic controller, said first modem directly connected to an expansion input/output bus of said first programmable logic controller, said first modem not utilizing a central processing unit communications port;

a second programmable logic controller; and

a second modem coupled to said second programmable logic controller

said first modem adapted to communicate with said second modem via a telephone network.

2. A system, comprising:

a first programmable logic controller;

a first modem integral to the first programmable logic controller, said first modem directly connected to an expansion input/output bus of said first programmable logic controller, said first modem not utilizing a central processing unit communications port;

a second programmable logic controller; and

a second modem coupled to the second programmable logic controller

said first modem adapted to communicate with said second modem via a communications network.

3. A system, comprising:

a first modem integral to a first programmable logic controller, said first modem directly connected to an expansion input/output bus of said first programmable logic controller, said first modem not utilizing a central processing unit communications port; and

a second modem integral to a second programmable logic controller;

said first modem adapted to communicate with said second modern via a communications network.

4. The method of claim 3, wherein the communications network is the Internet.

5. A system, comprising:

a modulator integral to a first programmable logic controller, said modulator directly connected to an expansion input/output bus of said first programmable logic controller, said modulator not utilizing a central processing unit communications port; and

a demodulator integral to a second programmable logic controller;

said modulator adapted to communicate with said demodulator via a communications network.

6. A system, comprising:

a first programmable logic controller comprising an integral modulator, said modulator directly connected to an expansion input/output bus of said first programmable logic controller, said modulator not utilizing a central processing unit communications port; and

a second programmable logic controller comprising an integral demodulator;

said modulator adapted to communicate with said demodulator via a communications network.

7. A method for facilitating peer-to-peer communications between programmable logic controllers, comprising:

connecting a first programmable logic controller to a second programmable logic controllers via a modem integral to the first programmable logic controller, said modem directly connected to an expansion input/output bus of said first programmable logic controller, said modem not configured to utilize a central processing unit communications port;

transferring data between the first and second programmable logic controllers; and

disconnecting the first programmable logic controller from the second programmable logic controller.

8. A method, comprising:

modulating data in a first programmable logic controller, the modulated date transmitted via a modem directly connected to an expansion input/output bus of said first programmable logic controller, said modem not utilizing a central processing unit communications port;

transmitting the modulated data over a communications network; and

demodulating the modulated data in a second programmable logic controller.

9. A method, comprising:

coupling a first modem to a second modem, said first modem integral to a first programmable logic controller, said second modem connected to a second programmable logic controller, said first modem directly connected to an expansion input/output bus of said first programmable logic controller, said first modem not utilizing a central processing unit communications port; and

transferring data between said first modem and said second modem.

10. The method of claim 9, further comprising modulating data in the first modem.

11. The method of claim 9, further comprising transmitting modulated data over a communications network.

12. The method of claim 9, further comprising transmitting modulated data over an Internet connection.

13. The method of claim 9, further comprising receiving modulated data over a communications network.

14. The method of claim 9, further comprising demodulating received data in the second modem.

15. The method of claim 9, further comprising connecting the first modem and the second modem via a communications network.

16. The method of claim 9, further comprising disconnecting the first modem from the second modem.

17. The method of claim 9, wherein data is transferred between the first modem and the second modem via Modbus protocol.

18. The method of claim 9, wherein data is transferred between the first modem and the second modem via PPI protocol.

19. The method of claim 9, wherein data is transferred between the first modem and the second modem via an at least 10 bit modem protocol.

20. The method of claim 9, wherein data is transferred between the first modem and the second modem via a modem standard selected from V.21, V.22, V.22bis, V.32, V.32bis, V.34, V.34bis, and V.90.

21. A system, comprising:

means for coupling a first modem to a second modem, said first modem integral to a first programmable logic controller, said first modem directly connected to an expansion input/output bus of said first programmable logic controller, said first modem not utilizing a central processing unit communications port, said second modem integral to a second programmable logic controller; and

means for transferring data between said first modem and said second modem.

22. A system, comprising:

means for coupling a first modem to a second modem, said first modem integral to a first programmable logic controller, said first modem directly connected to an expansion input/output bus of said first programmable logic controller, said first modem not utilizing a central processing unit communications port, said second modem connected to a second programmable logic controller; and

means for transferring data between said first modem and said second modem.

23. A computer-readable medium containing instructions for activities comprising:

coupling a first modem to a second modem, said first modem integral to a first programmable logic controller, said first modem directly connected to an expansion input/output bus of said first programmable logic controller, said first modem not utilizing a central processing unit communications port, said second modem integral to a second programmable logic controller; and

transferring data between said first modem and said second modem.