Hi

I have a 315-2pn/dp and cp340 rs422/585. I want to connect to pm1200 schneider power analayzer by modbus rtu. I use tia v13.

I know for this job i have to buy cp341, but is it by cp340?

Please help me!

Hello,

yes, you can use also CP340 but you must program your own implementation of RTU protocol. If you decide you're not so skilled, look to this topic, our friend prepared his implementation on CP340 without dongle:

MODBUS RTU MASTER FOR CP340/341/441-X (NO DONGLE REQUIRED)

This implementation is only with Step7 v5.x as I know, so not for TIA.

Hello,

another solution can be use S7-1200 with CM1241 module for RTU connection to device. This is cheap solution in my opinion, then you can connect your S7-1200 with S7-300 via Profinet ports with S7 or user communication.

THANK YOU FOR ATTENTION.

I THINK THAT I BUY A CP341, IT IS BEST!

Hello,

yes, but you need buy also dongle as RTU Master permission, need plug it to back side of CP341. This can be not cheap  therefore users try find another cheaper solutions if they need.