Which PROFINET Conformance Class includes support for IRT (Isochronous Real-Time)?
C — CC-C (Conformance Class C)
CC-C is correct because it is the only conformance class that mandates IRT support, with certified switches and devices and the specific PHY hardware needed for isochronous operation. CC-A is wrong because it covers only basic PROFINET RT and NRT on a free topology, with no specific port-management requirements. CC-B is wrong because it adds LLDP, SNMP, topology protocols and MRP on top of CC-A, but still does not require IRT. CC-D is wrong because there is no officially recognised CC-D today; a new class oriented towards TSN is under development but not yet published under that exact name.
When tendering for a motion-control machine, write "CC-C certified" into the specification rather than just "PROFINET compatible": the latter is satisfied by CC-A devices that cannot run IRT.
- A.CC-A (Conformance Class A)
- B.CC-B (Conformance Class B)
- C.CC-C (Conformance Class C)✓
- D.CC-D (Conformance Class D)
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