Hello,

you can't use S7 communication PUT/GET via serial interface of S7-1200 CM module, you can use only Point to Point communication blocks and Freeport or Modbus RTU protocols in this case.

 Hello,

Just_Starting

I have to do this with RS485 but i see that S7 1200 provides special technology blocks to use this port such as MB_LOAD, MB_MASTER, MB_SLAVE.

Also by ethernet you mean profinet ? I have read that this two are diffrent and i could not find any ethernet radio module 

 that your mentioned special blocks MB_ are my mentioned Modbus RTU blocks, can be used via serial modules. With ETH as Dan sugested, it is expected use OUC via TCP/UDP protocols, no PN I expect here. This is simply user defined messaging same as you can prepare with Point to Point Freeport but via ETH/PN Port of CPU or CP, as HW is defined. This is specific to radio interfaces available. I remember also one my very old prj with ship tank management where we used radio with only serial ports and worked ok. In case it include ETH and can be configured with TCP/UDP protocols, is better than serial line, this is what Dan sugested in my opinion. Dan, pls can you confirm?

On all cases I recommend check that radio manual for its capabilities.