Protocol ‘COMx - Modbus’

See protocol description for the serial interfaces COM1 and COM2 Setting_COMx_Modbus: Setting COMx - MODBUS Setting COMx - Modbus.

The address assignment as well as a detailed description of all implemented Modbus functions can be found in the documentation “System Technology CPUs” in Communication with Modbus RTU Communication \ with Modbus® RTU and Modbus® TCP/IP.

In the CM574-RS, 128 kB data are available in the addressable flag range %M. This way, the entire Modbus address range 0000hex .. FFFFhex can be covered.