Multiple program storage within a programmable logic controller system

1. A method for storage and retrieval of programs and data within a PLC system, the PLC system including a plurality of modules including a memory host module including a CPU and memory, at least one option module including a CPU and memory, the at least one option module including a first option module and a second option module, the first module including a memory, a backplane interconnecting the memory host module and the at least one option module, the memory host module coupled to an external device, said method comprising the steps of:

storing a plurality of operating programs and data including a first and a second operating program and data in the external device coupled to the memory host module, wherein the first operating program and data corresponds to the first option module and the second operating program and data corresponds to the second option module;

retrieving the first operating program and data;

retaining the second operating program and data; and

transmitting the first operating program and data to the first option module.

2. A method according to claim 1 further comprising the step of transferring the first operating program and data for the first option module from the memory of the memory host module to the memory of the first option module via the backplane.

3. A method according to claim 1 further comprising the step of transferring the first operating program and data for the first option module from the memory of the first option module to the memory host module via the backplane.

4. A method according to claim 1 wherein the memory host module is further configured with an external device interface, said method further comprising the step of transferring the first operating program and data for the first option module from the external device through the memory host module, to the memory of the first option module via the backplane.

5. A method according to claim 1 wherein the memory host module is further configured with an external device interface, said method further comprising the step of transferring the first operating program and data for the first option module from the external device to the memory of the memory host module via the external device interface.

6. A method according to claim 1 wherein the memory host module further configured with an interface to the external device, said method further comprising the step of transferring the first operating program and data for the first option module from the first option module through the memory host module via the backplane, to the external device.

7. A method according to claim 1 wherein the memory host module further configured with an external device interface, said method further comprising the step of transferring the first operating program and data for the first option module from the memory of the memory host module to the external device via the external device interface.

8. A method according to claim 1 wherein the memory host module further configured with an external device interface, the first option module further configured with an external device interface, said method further comprising the step of transferring the first operating program and data for the first option module from the memory of the memory host module to the memory of the first option module via the external device interfaces.

9. A method according to claim 1 , wherein the memory host module further configured with an external device interface, the first option module further configured with an external device interface, said method further comprising the step of transferring the first operating program and data for the first option module from the memory of the first option module to the memory of the memory host module via the external device interfaces.

10. A method according to claim 1 further comprising controlling said PLC system and other PLC systems via said external device.

11. A method in accordance with claim 1 further comprising coupling said memory host module to at least two of the at least one option module.

12. A memory host for a programmable logic controller (PLC) system, the system comprising at least one option module further comprising an option module memory, said at least one option module including a first option module and a second option module, said first option module including a memory, said memory host comprising a memory, a central processing unit (CPU), and a backplane interface, said memory host coupled to an external device and configured to:

retrieve a first operating program and data, wherein the first operating program and data corresponds to said first module;

retain a second operating program and data, wherein the second operating program and data corresponds to said second module; and

transmit the first operating program and data to the first option module, wherein said external device is configured to store a plurality of operating programs and data including the first operating program and data and the second operating program and data.

13. A memory host in accordance with claim 12 further configured to selectively transfer the first operating program and data from said memory host to said memory of said first option module via said backplane interface.

14. A memory host in accordance with claim 12 further configured to automatically transfer the first operating program and data from said memory host to said memory of said first option module via said backplane interface.

15. A memory host in accordance with claim 12 further configured with means to transfer the first operating program and data from said memory host to said memory of said first option module via said backplane interface.

16. A memory host in accordance with claim 12 further configured to retrieve the first operating program and data from said memory of said first option module via said backplane interface for storage.

17. A memory host in accordance with claim 12 further configured with means to retrieve the first operating program and data from the memory of said first option module via said backplane interface for storage.

18. A memory host in accordance with claim 12 further comprising an external device interface adapted to be connected to said external device, and further configured to transfer the first operating program and data from the external device to said memory host via said external device interface.

19. A memory host in accordance with claim 18 wherein said external device interface is a serial interface.

20. A memory host in accordance with claim 18 further configured to transfer the first operating program and data from the external device via the external device interface to the memory of said first option module via said backplane interface.

21. A memory host in accordance with claim 18 further configured to transfer the first operating program and data from the memory of said first option module via said backplane interface to the external device via the external device interface.

22. A memory host in accordance with claim 18 further configured to transfer the first operating program and data from said memory host to the external device via the external device interface.

23. A memory host in accordance with claim 18 further configured to transfer the second operating program and data from the memory host via the external device interface to said second option module.

24. A memory host in accordance with claim 18 further configured to transfer the second operating program and data from said second option module that further comprises an external device interface to said memory of said memory host via the external device interfaces.

25. A memory host in accordance with claim 12 wherein said memory of the memory host comprises flash memory.

26. A memory host in accordance with claim 12 wherein said external device is coupled to said memory host via Internet.

27. A memory host in accordance with claim 12 wherein said memory host is coupled to at least two of the at least one option module.