How to communicate Eco-PLC PM554 with PM583-eth over RS485 protocol
Please be clear,
- RS485 is a HARDWARE specification. Its the "telephone".
- MODBUS is a PROTOCOL. It's the "language" you speak on the telephone.
There are examples of MODBUS ( Both RTU and TCP ) on the AC500 support website. You've previously asked for information about "RS485" but the RS485 cable can be used for things other than just modbus serial comms.
It is impossible for anyone to help you with "challenges" unless you can describe in more detail what your problem is.