§5.3 – Device Functionality

Communication Class

After determining the node class of the device, it is important to know where the device will be deployed so that it can effectively communicate with the necessary speed.


  • TCP/IP  and/or UDP/IP is used for configuration or parameter assignment. It is a slightly slower type of communication, but because of its availability in PROFINET, this allows for simple vertical integration into MES/ERP systems.

RT – Real Time

  • Real time transmission can be used in almost every node class; but will be employed most by devices used generally in factory automation. Typically these components update every 1 – 8 milliseconds.

IRT – Isochronous Real Time

  • IRT data transmission is high-speed, high-performance, and deterministic.  Examples include motion control applications with update times of less than 1 millisecond.

PROFINET conformance classes summary

Conformance Class

Furthermore, each communication class is part of a broader categorization of PROFINET devices.  These Conformance Classes incorporate other features, and manufacturers will define which functions will be supported by their device.  Then, the component is classified to help simplify its selection prior to usage, guarantee its properties, and ensure interoperability.

Watch this webinar for much more on conformance classes and development:

Rapid Way to PROFINET