pyModSlave is a free python-based implementation of a ModBus slave application for simulation purposes. You can install the pythonmodule or use the precompiled (for Windows only) stand alone GUI (Qt based) utility (unzip and run). pyModSlave also includes a bus monitor for examining all traffic on the bus. You can also download it from pypi <https://pypi.org/project/pyModSlave/>.
Pythonmodule for network variables for CoDeSys PLCs
CoDeSys v2.3 supports so called network variables. Blocks of (global) variables, that propagates over networks like TCP, UDP or UDP Multicast aso.
This pythonmodule supports parsing, receiving and sending those blocks (with UDP Multicast only).
With this you can add for example a Raspberry Pi Sensor to your automation network without special Network clients on your PLC.