Hi,

I want to establish Modbus RTU slave communication using a Siemens S7-300 PLC (314-2DP), where the PLC acts as the slave. I’ve purchased a CP341 communication processor along with the slave dongle for this purpose. Software: TIA Portal.

I'm new to the S7-300 series. If I use the MB341 function block for Modbus communication, where do I define or assign the data that needs to be sent to the master (client) system?

In the S7-1200 PLC, I usually send data through a specific Data Block (DB). How is this handled in the S7-300 setup using the MB341 block?

Thank you in advance for your guidance!

Hello,

you can check https://support.industry.siemens.com/cs/de/en/view/109474714 .

Regards