how to connect arduino board in PLC?????
Do not hijack. Thread split.
Use some wires from Arduino to PLC.
Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
What model Arduino and what model PLC.
What is your application?
What do you want to communicate between the two?
Simple slow digital ON/OFF?
High Speed comms (RS232)?
It is possible for Arduino to connect to PLC, but doing what is the question.