System, method and computer program product for providing an interface for instantiating additional programmable logic controller functionality

• US 20050228516A1
• Filed: 04/06/2005
• Published: 10/13/2005
• Est. Priority Date: 04/13/2004
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens Energy & Automation Incorporated (Siemens AG)
• Inventors: Phillips, Scott, Christiansen, Rick
• Granted Patent: US 7,269,464 B2
• Time in Patent Office: Days
• US Class Current: 700/87
• CPC Class Codes: G05B 19/056 Programming the PLC

Abstract

Embodiments of a system, method and computer program product are described for instantiating additional programmable logic controller (PLC) functionality. In accordance with one embodiment, an extension for a PLC may be identified and loaded into a memory space of the PLC. The loaded extension has an initialization interface that may be exposed to the PLC. When the initialization interface is invoked, functionality of the PLC may be passed to the extension as at least one parameter of the invoked initialization interface. The extension can then be initialized utilizing the passed functionality.

Claims

1. A method of initializing an extension for a programmable logic controller (PLC), comprising:

identifying an extension for a PLC;

loading the identified extension into a memory space of the PLC, the extension having an initialization interface exposed to the PLC;

invoking the initialization interface;

passing functionality of the PLC as a parameter of the invoked initialization interface to the extension; and

initializing the extension utilizing the passed functionality.

2. The method of claim 1, wherein the PLC comprises a Soft PLC.

3. The method of claim 1, wherein the extension comprises a plug-in.

4. The method of claim 1, wherein the extension comprises a library.

5. The method of claim 4, wherein the library comprises a dynamic link library (DLL).

6. The method of claim 1, wherein a registry is searched to identify the extension.

7. The method of claim 6, wherein the registry is searched at start up of the PLC.

8. The method of claim 1, wherein the functionality of PLC comprises public functionality of the PLC.

9. The method of claim 1, wherein the functionality of PLC comprises functionality associated with a virtual central processing unit (CPU) of the PLC.

10. The method of claim 9, wherein the invoking of the initialization interface occurs before the virtual CPU transitions to a power-on state.

11. The method of claim 1, wherein the passed parameter exposes a registration of the PLC to the extension.

12. The method of claim 1, further comprising:

invoking a finalization interface of the extension;

passing functionality of the PLC to the extension as a parameter of the invoked finalization interface; and

finalizing of the extension utilizing the passed parameter of the finalization interface.

13. The method of claim 12, wherein the finalizing of the extension includes de-registering the extension.

14. The method of claim 12, wherein the finalizing of the extension includes releasing a resource of the PLC.

15. The method of claim 12, wherein the finalizing occurs before destruction of a virtual CPU of the PLC.

16. A computer program product for initializing an extension for a programmable logic controller (PLC), comprising:

computer code for identifying an extension for a PLC;

computer code for loading the identified extension into a memory space of the PLC, the extension having an initialization interface exposed to the PLC;

computer code for invoking the initialization interface;

computer code for passing functionality of the PLC as a parameter of the invoked initialization interface to the extension; and

computer code for initializing the extension utilizing the passed functionality.

17. A system for initializing an extension for a programmable logic controller (PLC), comprising:

an extension having an initialization interface;

a PLC having a framework adapted for identifying the extension and loading the extension into a memory space of the PLC; and

the framework being further adapted for invoking the initialization interface and passing functionality of the PLC to the extension as a parameter to the invoked initialization interface, wherein the extension is initialized utilizing the passed functionality.

18. The system of claim 17, wherein the PLC comprises a Soft PLC.

19. The system of claim 17, wherein the extension comprises a dynamic link library (DLL).

20. The system of claim 17, wherein extension has a finalization interface, wherein the framework is adapted for invoking the finalization interface, and passing at least one function of the PLC to the extension as a parameter to the invoked finalization interface for finalizing the extension.