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Connecting to a WAGO Controller via Modbus (TCP)


  • 1x WAGO fieldbus coupler 750-352/000-001
  • 1x digital input terminal 750-401
  • 1x digital output terminal 750-504
  • 1x end terminal 750-600

Requirements for the WAGO controller

  • Assign the IP address (for example with the tool WAGO Ethernet Settings).
  • Activate Modbus protocol (TCP) (for example with the tool WAGO Ethernet Settings → Protocol).
  • Get the manual for the fieldbus coupler.

Requirements for CODESYS

  • Create a standard project and define your device (for example CODESYS Control Win V3).

Scan the network and select the device.

  • In the device tree, add an Ethernet adapter, a Modbus_TCP_Master, and a Modbus_TCP_Slave.

Settings on the Ethernet adapter

  • Tab General

Define the network interface to be used.

If a target system is not defined yet, then the error message "Gateway not configured" is displayed.

Settings on Modbus_TCP_Master

  • Tab General

Activate the automatic establishment of a connection after interruption.

Settings on Modbus_TCP_Slave

  • Tab General

Specify the IP address of the WAGO controller and leave the Unit ID blank.
For Modbus via TCP/IP, the slave is identified by means of the IP address.

  • Tab Modbus Slave Channel

Create a channel for reading the input adapter:

Create a channel for switching the contacts of the output adapter:

  • Tab Modbus TCP Slave I/O Mapping

So that the Modbus addresses are updated even without variable mapping, you have to activate this explicitly:

Download the project to the controller and start it