ET200SP - Modbus RTU with 20 Slaves

[LKMNVRS]

Hello Forum,

I am having S7-400H Connecting with ET200SP through Ethernet & 1 Modbus Communication Module (6ES7137-6AA00-0BA0).

I am having 20 devices of 3rd party as slaves, which I need to communicate with them through Modbus RTU - RS-484 - 2 Wire mode.

I had only 1 clarification, all the devices I connect are of same baud rate & same communication settings. So, I will use 1 - Modbus Comn Load (FB640) & 20 Modbus Master blocks (FB641).

For every, Modbus master block, there will be an DB generated & that DB need to be linked Modbus Comm Load (MB_DB) parameter. So, for other 19 DB, where i need to connect to MB_DB

OR

I have to call 1 Modbus Cmn Load & 1 Modbus master as an set of 20.

please help...!

If any sample program for communicating with Multi request...Please provide

[capsute]

same db,different device ID.

[SHKODRAN]

Hello everybody.

I have neeed too the library modbus rtu , can someone share ?

Thanks in advance.

Regards.