Exchange data with Logix based PLC's via Python

bside · Jul 26, 2016

Archie said:
I looked back to find what we changed to make multiple copies of PyComm work with the same PLC and it was in this region of code:

Code:

self.attribs = {'context': '_pycomm_', 'protocol version': 1, 'rpi': 5000, 'port': 0xAF12, 'timeout': 10, 'backplane': 1, 'cpu slot': 0, 'option': 0, 'cid': '\x27\x04\x19\x71', 'csn': '\x27\x04', 'vid': '\x09\x10', 'vsn': '\x09\x10\x19\x71', 'name': 'Base', 'ip address': None}

I do not remember exactly, but we changed the value for either cid or csn. As I mentioned, I'm not a Python programmer, so I wasn't sure the best thing to do, so we just changed the value. Just a recommendation, but making it a random generated number would avoid the problem of 2 devices trying to connect to the same PLC.

That's the right place and 'cid' is the right property. 'sel.attribs' is a dictionary with the attributes of the class, so if you need to change the CID then you can use my_class.attribs['cid']='/x01/x02/x03/x04/' (with my_class being an instance of pycomm)

In this way you can easily map an external configuration file to the dictionary, and that's why I didn't make a random number. Anyway these feedback is very helpful, so I will make a change sooner.

thanks
Ago

bside · Jul 26, 2016

Peter Nachtwey said:
BTW, if you want a good implementation of python then get the anaconda package. It includes numpy, scipy and matplotlib.
I just use idle for editing for now.

I will give it a try, for me pycharm works really well. The community edition is free and is very well integrated with github and lots of other good stuff

Ago

Epy · Jul 26, 2016

Hi, as an additional option, you can use libplctag (a C library for the same thing) which has a Python wrapper. The main developer is currently seeking input on the functionality of the library for v2.0. Have a taste: https://github.com/kyle-github/libplctag

Edit: I should also add that once you compile the library, one of the produced executables is a command-line utility called tagrw that allows you to read/write tag values for Logix/PLC5/SLC500/MicroLogix etc.

Shane.platt · Nov 3, 2019

Love this Module!!! It works like a charm!

ehab.ridy · Jul 2, 2020

Thanks dmroeder
I followed your instructions on a video I found on youtube.
I haven't tried it yet but going to now. Thanks for the effort though and have fun "tinkering"

Exchange data with Logix based PLC's via Python

bside

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Epy

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ehab.ridy

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