All PROFINET products are developed according to international standards and certified by PROFIBUS and PROFINET International (PI). Every PROFINET device has a defined set of features that are mandatory based on its conformance class. There are three PROFINET conformance classes: A, B, and C. Conformance Class A (CC-A) is the most basic, while C (CC-C) is the most advanced. The Conformance Classes build upon each other; for example, CC-C contains all functions from CC-A and CC-B. The table below summarizes the characteristics of each Conformance Class.
All PROFINET devices support real-time data exchange, standardized alarms and diagnostics, and network topology support. PROFINET devices have built-in standard diagnostics and alarms with specific PROFINET errors, such as invalid read/write area, device not accessible, and data length error. Also, PROFINET devices have built-in network topology support. The user can read out topology information with standard PROFINET tools.
Aside from the standard diagnostics and topology support in all PROFINET devices, CC-B devices support Simple Network Management Protocol (SNMP). With SNMP support, users can employ standard SNMP tools to read out topology information, network statistics, and other related network details.
In addition to SNMP, CC-C devices also support PROFINET Isochronous Real Time (IRT). PROFINET IRT is a PROFINET communication channel used for the most demanding applications. With PROFINET IRT, it is possible to achieve cycle times of 31.25 µs and 1 µs of jitter.
Beyond Conformance Classes
Aside from the mandatory characteristics in each PROFINET device, PI defines a list of optional features. These features are not required in PROFINET devices; nonetheless, they can provide tremendous added value. For example, some of these features are Device Redundancy, Controller Redundancy, Shared Device, Dynamic Reconfiguration, Fast Startup, and iPar Server. If you would like to learn more about several PROFINET optional features, watch the following webinar: