Playing with simple Modbus TCP on a NodeMCU0.9 using PlatformIO in VS-code
The code is the first 10 holding registeres [0-9] or 40001+[0-9] you can also write to the next and they will be sent to out via the serial monitor
have fun - and remeber, only 1 client can be connected to a modbus server a time.
The good old NodeMCU0.9 :)Testing with qModMaster, see under test folder
I also tested it with a Universal Robot CB3 sim (URSim) You can downloaded it from UR Homepage (https://www.universal-robots.com/)
Example on Read and Write to the modbus holding registeres
As always... Have fun with the data and code