Profinet Conformance Classes Explained

PROFINET Conformance Classes refer to a classification system within the Profinet communication protocol that defines different levels of compliance and features that devices must adhere to in order to ensure interoperability and compatibility within a Profinet network. These classes help manufacturers and users understand the capabilities and functionalities of Profinet devices. Each conformance class specifies certain requirements, such as supported features, performance, and testing procedures.

CC-A: This covers the use of the infrastructure of an existing Ethernet network, including the integration of essential PROFINET functions. All IT services can be used with no restrictions. CC-A devices are used in typical building automation and process automation applications.

CC-B: The functional scope of CC-B comprises the functions of CC-A and supports easy, user-friendly device replacement without the requirement for additional tools. Furthermore, Simple Network Management Protocol (SNMP) supports extended device diagnostics of network functions, like port status messages. An optional performance-adapted media redundancy protocol is also provided to improve data reliability, and all IT services can be used without restriction. Typical applications for CC-B devices include automation systems with higher-level machine control with deterministic, but not isochronous, data cycles.

CC-C: The scope of CC-C includes all the functions of CC-B, but it additionally supports high precision and deterministic data transmission, including isochronous applications. In the event of a fault, Integrated optional media redundancy enables smooth switchover of the I/O data traffic. All IT services can be used without restriction. Typical applications are in the field of motion (motor) control.

CCD: The conformance class has only recently been released. Devices conforming to this class implement Profinet using Time-Sensitive Networking (TSN). It implements the same functions as CC-C. However, unlike CC-A and CC-B, all communication (cyclic and acyclic) between a controller and a device occurs over Ethernet layer 2 using the newly introduced Remote Service Interface (RSI).

Manufacturers design their devices to meet specific Profinet Conformance Classes, indicating the level of compatibility and performance they can offer within a Profinet network. This classification ensures that devices from different manufacturers can work together seamlessly while maintaining the required levels of functionality and performance.