Modbus TCP-IP Client-Master commissioning

FX substation Modbus TCP-IP (Client-Master) activation

Modbus TCP-IP Client feature shall be activated as followed: 

  1. At the Settings -> Activations page check if your FX substation version supports Modbus TCP-IP client feature

    If no record found, please update your FX substation to het version 12.30.06 or newer.

    Go to the and enter "Product code" from Modbus Server record line.
    Enter received activation key (6 symbols) to the "Activation key" field and press "Change" button. Check if "Product activation OK" appears.

  2. To enable communication over Modbus TCP-IP, go to the Settings -> Ports and select any of ports 6..10 and set it to "Modbus TCP". Set the sending delay to something like 100..200 ms. The slower the Modbus  TCP-IP Server system, the higher value should be.
    Press "Change" to save changes.

  3. Make sure that AHU (Modbus TCP-IP Server) IP address is in the same IP subnet as the FX substation.
    If using FX3000-C, FX-SPIDER-40/10, check if AHU is connected to proper LAN or WAN network.
    FX3000-C with AHU connected to LAN. 
    Set AHU IP to
    Set AHU Default GAteway to
    Set AHU subnet mask to
  4. Check the AHU register requirements and create corresponding Modbus device:
    Programming -> Modbus devices
    E.G. if in the OpenPCS interface (documentation) is following: CREATE MODBUS DEVICE: HOLDING REGISTERS, STARTING REGISTER: 201, NUMBER: 64

1. Select port previously set to "Modbus TCP"
2. Set Modbus device address on the port 1..255. Applicable if several Modbus TCP-IP servers to be connected on the same port.
3.4.5. Select register type, starting and number of registers to be read in a queue. 
6.7. Set  TCP/IP module, IP address, and IP port (Default is 502) belonging to the AHU.
8.9. Check if communication established: "Messages Total" is bigger than zero and some values are shown in the table below.

 Now the FX substation is communicating with Modbus TCP-IP  and ready for transferring register values to points using IEC program.