Each ModbusTcpGatewayDevice you add under a ModbusTcpGateway requires the unique Modbus address (1—247) used by that device on serial “far-side” of that gateway. When using the Modbus Tcp Gateway Device Manager view to create new devices, the popup dialog allows you to enter this “Starting Address”, as shown in Figure 17.

Note this dialog allows you to add a sequentially-addressed range of multiple ModbusTcpGatewayDevices, by setting “Number to Add” more than 1, with the first device using the starting (Modbus) address. This may be useful in cases where all devices in that range will have a different set of proxy points.

However, in cases where you have “like devices,” you might create a single ModbusTcpGatewayDevice first, configure its proxy points and other components as needed, and then duplicate it as many times as needed. Then you can change the “Device Address” of each duplicate to a unique number, as needed.

When you click OK in the dialog shown in Figure 17, 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.