This is the proxy extension for either a ModbusServerNumericPoint (NumericPoint) or ModbusServerNumericWritable (NumericWritable) in a server Modbus device. The server NumericPoint acts as an “input,” where holding register values are written by the master. The server NumericWritable acts as an “output,” where station values can be written as either input register or holding register values.

For more details, see Modbus server proxy points.