Read/write I/O addresses in pylogix

I'm currently working with pylogix and have no trouble reading and writing tags. My problem is, I would like to be able to read (and write) I/O points (e.g. I:2/1) or bits (e.g. B3:1/1) directly. Does anyone know how to do this?
Thanks
Gary

Welcome to the forum Gary!

The addressing you are referring to seems to be SLC/MicroLogix/PLC5 type addressing. Pylogix only supports ControlLogix, CompactLogix and Micro820/850. It does not support MicroLogix, SLC, PLC5 etc.

ControlLogix and CompactLogix use this addressing too it's just that with the newer processors, they ability was added to reference them using tags to make things more readable. From your reply, it sounds like pylogix can only reference by tag. Bummer.


Thanks
Gary

GaryA said:

ControlLogix and CompactLogix use this addressing too it's just that with the newer processors, they ability was added to reference them using tags to make things more readable. From your reply, it sounds like pylogix can only reference by tag. Bummer.


Thanks
Gary

Click to expand...

Edit: Oh wait, you must be using the SLC/PLC mapping in the CLX and want to access data from the CLX using the SLC addressing. Unfortunately this won't work, you must read/write by tag name. Essentially, anything in the tag database is accessible using pylogix (with a couple of caveats).

May I ask, why you are you are wanting to access it this way and not getting at the tags directly? Just curious.

The goal, at the moment, is to read/write data on an old PLC5/40e using Python. I can't find anything to my liking that talks directly to the PLC5 so, the current plan is to talk to it from a old ControlLogix I have on the shelf (1756-L1) and connect thru the DH+. So, using tags to the CLX isn't the problem directly, I just have to add them. It would be nice if pylogix (or something else) would allow me to do this directly to the PLC5 or, to it via the CLX but, as an alternative, I can set it up to sync certain data between the two. When I read the pylogix document, it showed a line of custom CIP routing which, I hoped, would be my way in.



I'm still pretty green on some of this so, I would appreciate any input you might have on what i'm doing/planning. I've done quite a bit of basic programming on older A/B stuff and Siemens S5 but CLX and communications between PLCs and PLC to PC is new to me.



Thank you for your help, BTW. And thanks for pylogix. I think it's going to end up being a great help!

Pylogix doesn't support custom CIP routes, maybe that is a fork. A pull request was submitted, though it had some issues. The main reason I haven't added the support is that I just don't have the hardware handy to test. I don't want to add something that I don't have the ability to support.

Have you looked at pycomm?

https://github.com/ruscito/pycomm

If you aren't fully committed to python, check out AdvancedHMI. It has the ability to do what you are after.

https://www.advancedhmi.com/