data transfer through modbus

[kelummaduranga]

hello,

I have a s7 400 plc with cp-441-2 communication processor .(6es7 441-2aa03-0ae0). i want to using RS422/485 (x27) point to point modbus protocol to send data to third-party devise. pls help how can i do this thanks.

[PLC_ITA]

It's difficult to understand what you want to do. From the title of the post, it seems you want to communicate in Modbus RTU.
In the meantime you have to understand how many wires the system has 2 (half duplex) 4 full duplex, then set this in the hardware. You also set the communication parameters ( baud, parity etc).
To communicate in Modbus with the 441 card, if I remember correctly, you need the DONGLE which is a license. in the package there is a module that must be inserted in the rear part of the CP.
Once this is done, download the CP PTP software, install it and also Modbus master or Modbus Slave depending on your configuration.
Once this is done you need to understand what you need to communicate (holding register....coil etc) and set the related routine.
Modbus it' easy, buy If do not have an experience the first time all it's difficult!

PLC ITA

[kelummaduranga]

dear PLC_ITA ,
thank for your advice and solved the problem with modbus communication. thank you very much.