Solution:

The master can send a Modbus broadcast messages (using a slave address of 0), which all slaves accept, but do not reply to. Since the Modbus ID Routing table can only be used for slave ID’s we have the broadcast routing table in a separate window. Information below found in Help bar. The first box in line is used to set a serial port (which has slave devices attached) of modbus gateway on which broadcast message is received or IP address from which broadcast message is received. The second box in line is an IP address from which broadcast message is received if IP address is chosen in the first box. The third box in line is used to set a destination port (which has slave devices attached) or IP address to send broadcast messages. The fourth box in line is an IP address to send broadcast messages if IP address is chosen in the third box.