I/O configuration for Modbus TCP Client

Hello and good day I am having trouble with the softplc modbus tcp client. How do I configure the inputs outputs ? I have 16 outputs 24 inputs so I set input offset for 16 and 24 count but inputs are outputs. also I managed to locate a output %M1 and its extremely unstable it goes on for half a second then off for half a second like a strobe any help would be appreciated

Hi @mmd604 !
Could you please post screenshots of your configuration in Factory I/O and also of the inputs and outputs in the SoftPLC you’re using?
Thank you!

Screenshot 2020-12-11 161442

I can located the outputs(inputs) on the right but I can find the start button. For outputs(inputs) %m0 move X %m1 move Z

Thank you, @mmd604.
I’m afraid I still need more information. If you wouldn’t mind also posting the software used, and especially the I/O mapping, I would appreciate it.

I have moved on using codesys opc ua instead.


it is strange, I don’t have any problem in Modbus TCP with the soft PLC from EcoStruxure Machine Expert - Basic (M221).
If you want me to est your application, do not hesitate.


Thanks for all your help but I prefer codesys. Schneiders software is very glitchy

Have you seen this post ? It could be useful for you if you use CODESYS.