Communication via Standard Ethernet

How does CODESYS communicate via Ethernet? How can I send and receive data from a CODESYS-compatible PLC via TCP or UDP? How can I realize data exchange from the PLC application?

Today, almost every industrial controller has an Ethernet connection. It is usually used for programming the device and exchanging data with other systems. The physical interface can be used with different protocols.

For communication with I/O systems, motors, or intelligent units of the control architecture, Industrial Ethernet protocols are commonly used. For more information, please click here.

Ethernet with TCP/IP is used in CODESYS not only for programming, but also for communication with CODESYS Visualizations, e.g. with CODESYS HMI or CODESYS WebVisu.

From the IEC 61131-3 logic application, users can also exchange dedicated data. The free network.library is based on the library CAA Net Base Services and is included in the scope of delivery of the CODESYS Development System. This library provides a convenient interface for socket communication from the controller to other systems via TCP/IP and UDP.

The functions of the free RPC.library can also be used to address or release the client/server procedures on the controller ("Remote Procedure Calls").

How can you use Ethernet in CODESYS?

You are a system integrator or a user in the machine/plant construction sector or the like:

  • Program CODESYS-compatible controllers or standard device platforms that are equipped with integrated Ethernet interfaces.
  • Connect additional visualization devices, e.g. operating panels equipped with CODESYS HMI or HTML5 browsers that display the CODESYS WebVisu.
  • Send and receive controller data from the IEC 61131-3 logic application via the available function blocks of the network.library.

You are a manufacturer of programmable devices:

  • Implement in your devices the required communication components of the CODESYS Runtime Toolkit, as well as the possibility to license libraries per device.

Beratung, Angebot und weitergehende Informationen durch


CODESYS brochures and information material

CODESYS - One software. All applications. Your Automation Solution.
Version: 10/2023
pdf 2 MB
CODESYS - One software. Any field of application. Your automation platform.
Version: 10/2023
pdf 2 MB
Various suppliers present CODESYS-compatible devices and exciting solutions that can be useful for your automation tasks. (Only available in german language.)
Version: 11/2022
pdf 3 MB