Modbus RTU Master with CP341

[Popescu Stefan]

Hello everybody,

I have a S7-300 PLC with a CP-341, I need to read with it 2 PM500 and a Tweedo using the protocol Modbus RTU Master.

I downloaded the documantation but unfortuanlly I still didnt manage to read the data.

I'm a bit confused as to where I need to put the address of the devices and where I need to put the address of data I want to read.

Please help me.

 

[Popescu Stefan]

I did'nt quite understand how to implement the function codes in the program, and if i need to use FB7 or FB8 from the CP library.

If anyone has an example of a simple program please send to [email protected]

Thank you