Each ModbusTcpDevice you add under a ModbusTcpNetwork requires the IP address used by that device. Usually, each Modbus TCP device uses this address (only) for communications, with its “Modbus address” (1—247) often left at “1”.

However, when using the Modbus Tcp Device Manager view to create new devices, the initial popup dialog allows you to enter this Modbus “Starting Address”, as shown in Figure 13, and you enter the IP address in the subsequent dialog.

Note the initial dialog allows you to add a sequentially-addressed range of multiple ModbusTcpDevices, by setting “Number to Add” more than 1, with the first device using the starting (Modbus) address. This technique is probably more useful in a ModbusAsyncNetwork, where devices do not use IP addressing. It is recommended you leave the “Device Address” at 1 for all ModbusTcpDevice objects, unless vendor’s documentation for Modbus TCP devices state otherwise.

Note in cases where you have “like devices,” you might create a single ModbusTcpDevice first, configure its proxy points and other components as needed, and then duplicate it as many times as needed. Then you can change the “Ip Address” property of each duplicate to the IP address in use, as needed.

When you click OK in the initial dialog shown in Figure 13, the next New dialog provides a number of “standard” new device properties to enter (such as Name and Enabled), and others common to all client Modbus devices (ModbusAsyncDevice, ModbusTcpDevice, ModbusTcpGatewayDevice). For more details on these Modbus-related properties, see About Modbus client devices.