How to Connect to CODESYS using a Remote I/O and an HMI

How to Connect to CODESYS using a Remote I/O and an HMI

This tutorial will demonstrate how to connect an iR-ETN40R Remote I/O and a cMT device using CODESYS while communicating via Modbus.

Software Required

Hardware Required

Network Design


LAN1:CODESYS to Switch

LAN2: cMT Device to Switch

iR-ETN40R to Switch

PC Application to Switch

Remote I/O Configuration (iR-ETN40R)

Launch EasyRemote IO and click [Scan] to find the iR-ETN40R’s IP settings. Then click [OK] to open EasyRemote IO’s main menu.

Go to [Online] >> [Start Monitoring] to go online with the iR-ETN40R.

Go to [File] >> [Export PLCopenXML] to export the xml file to be used in CODESYS.

CODESYS Ethernet and Modbus Configuration

Launch CODESYS and add an Ethernet Device. Right click on [Device] and click [Add Device]. Click the [+] on Fieldbuses. Click the [+] on Ethernet Adapter. Check [Display all versions]. Select [Ethernet]. Click [Add Device].

Enter the CODESYS IP address, Subnet Mask and Gateway.

Right click on [Ethernet] and click [Add Device]. Click [+] Modbus. Click [+] Modbus TCP Master. Check off [Display all versions]. Select [Modbus TCP Master]. Click [Add Device].

Select the [Modbus TCP Master] device. Click on [Project] and click [Import PLCopenXML]. The iR-ETN40R’s Modbus TCP Slave device and IP address is populated.

Select the Device.

The Modbus TCP Slave device populates.


To go online in CODESYS go to [Online] >> [Login]

CODESYS has established Modbus connection and is now online and displaying in RUN mode.

Sample Project

The project shown above was designed for the specific hardware mentioned at the beginning of the tutorial and is intended to provide you guidance when programming your unit. If you are using models other than the ones specified in this sample project, similar steps can be duplicated within your own project.

Download CODESYS Sample Project
Download EasyRemote IO Sample Project
Download EBPro Sample Project

Resources & Documentation

CODESYS Resources


See our Support Center for a complete list of Quick Start and Installation Guides

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