Configure Modbus-RTU

Use Modbus-RTU to enable data transmission between devices using the Airwall Gateway serial interface.

  1. Connect an RS-232 Modbus Program Logic Controller (PLC) to your Airwall Gateway using a DB9-to-DB9 or DB9-to-RJ45 cable.
    Note: RS-485 is supported by the Airwall Gateway/HIPswitch-250, but others will require an adapter.
  2. Go to Airwalls>Airwalls>Ports>Serial over IP
  3. Click Edit Settings, and then configure SoIP using the Generic Serial Over IP communications protocol.

  4. Add the SoIP device to an overlay and create policy.
  5. Using Modbus Polling software, such as FieldTalk's ModPoll, test the configuration using a command such as the following: modpoll -m rtu -r 1 -c 125 -1 -p 4001