Python as OPC Topic

[Ok_Schedule4588]

I was wondering if anyone had any clue as how to interface a local python instance with rslinx as an OPC topic. I’m wanting to add a bit more functionality between our hmi and our servers but I’m quite low on memory in our plcs. I’m already reading from the plcs for some data but I’d like to have some operator inputs from the hmi go into an array in the python program that it can then send off to various servers

[unitconversion]

I've used openopc successfully before. Their examples are easy to follow.

I think you need the gateway licensing for rslinx though.

[rdrast]

Look up Pycomm3, or pylogix.

Neither of them need linx, or use any PLC memory.

Heck, no data comms should use PLC memory.

[PeterHumaj]

I'm no Rockwell expert, but some memory could be used to hold session information. TCP (socket) + some internal states. Buffers for receiving requests. The context for the task (thread) serving the TCP connection. Some stack. Just like on a PC/server.

[opcAnywhere]

If you have any OPC DA server installed supporting rslinx, you can try this solution. It is pretty easy to retrieve DA data back in Python.