Programmable logic controller provided with communication functions in a client-server architecture

• US 6,721,607 B2
• Filed: 01/25/2001
• Issued: 04/13/2004
• Est. Priority Date: 01/26/2000
• Status: Expired due to Fees

• Current Assignee: Schneider Automation (Schneider Electric SE)
• Original Assignee: Schneider Electric Industries Sa (Schneider Electric SE)
• Inventors: Brault, Gilbert
• Primary Examiner(s): Grant, William
• Assistant Examiner(s): HARTMAN JR, RONALD D
• Application Number:
  US09/768,619
• Publication Number:
  US 20010014833A1
• Time in Patent Office: 1,174 Days
• Field of Search: 700/83, 700/67, 700/18-19, 700/9, 700/20, 700/23, 700/65-66, 700/86, 709/106-107, 709/220, 709/221, 709/223-225
• US Class Current: 700/18
• CPC Class Codes: G05B 19/05 Programmable logic controllers, e.g. simulating logic interconnections of signals according to ladder diagrams or function charts

Abstract

A programmable logic controller system including a private operating system that does not support a TCP/IP protocol, and a communication module connected to a private communication bus and a TCP/IP network, and at least one intelligent module. The communication module includes TCP/IP connection and communication functions, a plurality of delegation services, and a transcoding and routing service configured to encode, decode, and route a request. The private communication bus includes a plurality of supported protocols. Further, the at least one intelligent module includes an HTTP server and at least one application having an application programming interface. The application programming interface is configured to use the TCP/IP connection and communication functions from a remote location. In addition, the plurality of delegation services are configured to enable the at least one application in the at least one intelligent module to delegate services to the communication module on the TCP/IP network.

Claims

1. A programmable logic controller system, comprising:

a private operating system that does not support a TCP/IP protocol;

a communication module connected to a private communication bus including a plurality of supported protocols, and a TCP/IP network, said communication module including;

TCP/IP connection and communication functions,

a plurality of delegation services, and

a transcoding and routing service configured to encode, decode, and route a request; and

at least one intelligent module comprising an HTTP server and at least one application having an application programming interface configured to use the TCP/IP connection and communication functions from a remote location,

wherein the plurality of delegation services are configured to enable the at least one application to delegate services to the communication module on the TCP/IP network.

2. The programmable logic controller system according to claim 1, wherein the plurality of delegation services comprise:

a server delegation service configured to enable the at least one application to delegate to the communication module opening and management of a server connection on the TCP/IP network;

a client delegation service configured to enable the at least one application to delegate to the communication module opening and management of a client connection on the TCP/IP network; and

a multicast delegation service configured to enable the at least one application to delegate the communication module opening and management of a multicast connection on the TCP/IP network.

3. The programmable logic controller system according to claim 2, wherein the transcoding and routing service encodes the request originating from one of the plurality of delegation services using one or more of the plurality of supported protocols, routes the request to the at least one intelligent module, decodes the request from the at least one intelligent module, and routes the request to one of the plurality of delegation services.

4. The programmable logic controller system according to claim 3, wherein the communication module is connected to remote equipment through the private communication bus.

5. The programmable logic controller system according to claim 3, wherein the application programming interface comprises:

a plurality of functions configured to approximate GNU C compiler libc library functionality with additional encoding arguments to facilitate transport on the private communication bus and to be interpreted by the plurality of delegation services, and to route messages from the application programming interface on the private communication bus.

6. The programmable logic controller system according to claim 5, wherein a first call to one of the plurality of functions sends the request to one of the plurality of delegation services and initializes a status block transferred as a parameter to guarantee asynchronism between the at least one application and one of the plurality of delegation services, subsequent calls with the same status block are used to retrieve function return parameters, and wherein a message is sent to the at least one intelligent module when a function is terminated in the communication module.

7. A programmable logic controller system, comprising:

a private operating system that does not support a TCP/IP protocol;

at least one intelligent module including an HTTP server and at least one application having an application programming interface; and

a communication module connected to a TCP/IP network and a private communication bus supporting a plurality of supported protocols, wherein the communication module comprises;

TCP/IP connection and communication functions, said application programming interface of the at least one intelligent module being configured to use the TCP/IP connection and communication functions from a remote location,

a plurality of delegation services including a server delegation service configured to enable the at least one application to delegate to the communication module opening and management of a server connection on the TCP/IP network, a client delegation service configured to enable the at least one application to delegate to the communication module opening and management of a client connection on the TCP/IP network, and a multicast delegation service configured to enable the at least one application to delegate to the communication module opening and management of a multicast connection on the TCP/IP network, and

a transcoding and routing service configured to encode a request originating from one of the plurality of delegation services using one or more of the plurality of supported protocols, route the request to the at least one intelligent module, decode the request from the at least one intelligent module, and route the request to one of the plurality of delegation services.

8. The programmable logic controller system according to claim 7, wherein the application programming interface comprises:

a plurality of functions configured to approximate GNU C compiler libc library functionality with additional encoding arguments to facilitate transport on the private communication bus and to be interpreted by the plurality of delegation services, and to route messages from the application programming interface on the private communication bus.

9. The programmable logic controller system according to claim 8, wherein a first call to one of the plurality of functions sends the request to one of the plurality of delegation services and initializes a status block transferred as a parameter to guarantee asynchronism between the at least one application and one of the plurality of delegation services, subsequent calls with the same status block are used to retrieve function return parameters, and wherein a message is sent to the at least one intelligent module when a function is terminated in the communication module.