Create the connection to the modbus master
Select [Comms] from the [Setup] menu.
Enter the modbus address WinModbus should reply to. Your options are:
Select the protocol:
Select Network or Serial and enter the relevant setup information for the transport you have chosen.
For network, the standard ModbusTCP listen port is 502. For serial, you can set baud, parity and stop bits here as well as serial port. Data bits is automatically set depending on whether you are using Modbus ASCII (7) or not (8).
WinModbus only displays the currently available serial ports.If your serial port isn’t appearing in the list, ensure it is not in use by something else.
Note: You can mix Modbus TCP/RTU with serial/ethernet links which is useful for scenarios where you may be using a network terminal server to talk to a serial device.