Problem with the same kind of CPU.
Can S7-200 CN be ModBus master?

This can be a little confusing. The S7-200 PLCs can participate on a Profibus network as a "Master" in the sense that they manage token rotation on the bus, can bring other masters onlineand can initiate communication with otherdevices. However, the S7-200 does not act as a master in the sense that it can use the inputs and drive the outputs ofProfibus Slave devices.

This is my understanding.

Thanks to all for help. I made communication with ModBus protocol but i still have one problem. I can control only one device in net, but comands to other device not passing, and as a result i can't control It.
All requiments about adressing and connecting are passed. In program every data transmition to any address is isolated, only one transmition a time.
Perhaps it should be some time delais betveen messeges to diferent addresses?