Codesys to ControlLogix over Ethernet IP

Introduction

This tutorial provides a step-by-step guide on how to establish communication over EtherNet/IP between a Codesys PLC and a ControlLogix PLC. Understanding this process is essential for automation engineers looking to integrate different PLC systems effectively.

Step 1: Prepare Your Hardware

• Ensure that both the Codesys PLC and the ControlLogix PLC are powered on and connected to the same Ethernet network.
• Verify that your Ethernet/IP adapter is correctly configured and operational.
• Check the IP addresses assigned to both PLCs to ensure they are in the same subnet.

Step 2: Configure Codesys for EtherNet/IP

• Open the Codesys development environment.
• Navigate to the device tree and add a new EtherNet/IP device.
• Set the parameters for the EtherNet/IP adapter:
  • Enter the IP address of the ControlLogix PLC.
  • Set the port number to the default EtherNet/IP port (typically 44818).
• Define the necessary input and output assemblies as per your application requirements.

Step 3: Set Up ControlLogix for EtherNet/IP

• Launch the RSLogix 5000 or Studio 5000 software.
• Create a new project or open an existing one.
• Add the EtherNet/IP module to your ControlLogix system.
• Configure the module:
  • Input and output sizes must match those defined in the Codesys configuration.
  • Set the connection parameters, including the IP address of the Codesys PLC.

Step 4: Establish Communication

• In Codesys, create a network variable that corresponds to the ControlLogix variable.
• Use the appropriate function blocks to read from and write to the ControlLogix PLC:
  • For reading data, you might use a function block like EthernetIP_Read.
  • For writing data, utilize EthernetIP_Write.
• Ensure that the data types match between the two systems to avoid communication errors.

Step 5: Testing the Connection

• Deploy the Codesys application to the PLC.
• Go to the ControlLogix PLC and monitor the data being received from Codesys.
• Use diagnostic tools in both environments to verify that data is being transmitted correctly.

Conclusion

By following these steps, you can successfully establish communication between a Codesys PLC and a ControlLogix PLC over EtherNet/IP. This setup allows for effective data exchange and integration in automation projects. As a next step, explore advanced communication strategies or consider implementing additional features such as error handling and logging for improved reliability.