Python Forum

Full Version: PLC software developmenr
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
I AM NEW TO PYTHON IN SOFTWARE DEVELOPMENT , i NEED HELP IN SELECTING PROPER PACKAGES FOR PYTHON.

I WANTED TO BUILD APPLICATION USING LADDER LOGIC FOR PLC. I AM PLANNING TO USE ARDUINO MEGA/UNO FOR DEVELOPMENT PURPOSE.
sOFTWARE ALLOW THE USER TO CODE IN LADDER LOGIC AND BACKEND PYTHON CODE SHALL TAKE ACTION BASED ON USER INPUT SELECTION.

CAN SOMEONE SUGGEST ACKEND AND FRONT END PLC PACKAGE AND HOW GET STARTED WITH PLC SOFTWARE.
Please, don't use ALL CAPS. That is considered shouting. Repost/edit it.
You have to do the programming in the development software.
From outside you can access your PLC over Network with Python.
Which library you cold use, depends on the manufacturer and the supported protocol.

For expensive Siemens PLCs you can use: OPC UA Server on PLC, MQQT on PLC, Open Communication (TCP/UDP)
Low level access to Siemens PLCs can be done with snap7.
For OPC UA you can use https://github.com/FreeOpcUa/python-opcua

On time I built a bridge between real transportsystem controlled via PLCs and a simulation with Python.
For this task I used OPC UA, because some data structures were well converted, for example the datetime + tzinfo.
What OPC UA currently not supports on Siemens PLCs, is historical data.

Other manufacturers support other protocols.