Communication via IIoT libraries

All IoT communication protocols can be implemented and used on different transmission media via software . Data exchange is performed by explicitly calling functions or function blocks as part of the IEC 61131-3 control application.

With the library concept integrated in CODESYS, such protocols can be easily maintained and passed on as products after their implementation.

In the CODESYS Store, you will find the communication library CODESYS IIoT Libraries along with the corresponding application examples that implement different communication protocols (indicated in brackets).

  • MQTT Client (MQTT)
  • Web Client (http, https)
  • AWS IoT Core Client (MQTT)
  • Azure IoT Hub Client (MQTT, https)
  • Mail Service (POP3, SMTP)
  • SNTP Service (SNTP)
  • SNMP Library (SNMP)
  • SMS Service (SMS)

Auxiliary libraries help you simplify the communication even more, such as

  • JSON Utilities
  • XML Utility

For more libraries, also from third-party-suppliers, that implement IIoT protocols or connections, please refer to the CODESYS Store at Communication.

CODESYS does not yet support the protocol you need?

The CODESYS Development System is a powerful and modern programming tool. Use it to implement proprietary or standardized communication protocols yourself. In the free basic library network.library you will find the sub-library CAA NetBaseServices.library, which provides you with important basic services. Products created in this way can also be made available to other users in the CODESYS Store free of charge or for a fee (with complete licensing).

How can you purchase and use IIoT libraries for CODESYS?

  • Use controllers with adequate communication interfaces. The CODESYS Device Directory helps you find the suitable hardware. Alternatively, you can use the CODESYS Control SoftPLC systems from the CODESYS Store and install them on standard device platforms. Download CODESYS IIoT Libraries from the CODESYS Store and install the software package in the CODESYS Development System.
    Or you can develop your own protocol libraries, which you can make available to other users in the CODESYS Store. Have experienced specialists advise and support you in architecture design and implementation. Further information at CODESYS User Services.
  • You are a manufacturer of programmable devices: Implement the required communication components of the CODESYS Runtime Toolkit in your devices, as well as the possibility to license libraries per device.

More information at