PROFINET RT is a specified Industrial Ethernet Standard from the PI (PROFIBUS & PROFINET International) organization, and is based on proven TCP/IP and IT standards.
The PROFINET standard differentiates between three different performance classes.
PROFINET NRT (non-real-time)
This type is used for applications where the timing is not critical and uses Ethernet TCP/IP and also the UDP/IP protocol for data transfer. Cycle times >100 ms are achieved.
PROFINET RT (real-time)
With PROFINET RT, I/O data is exchanged directly using the Ethernet protocol, but diagnostics and communication data is still transferred via UDP/IP. PROFINET RT allows applications to be created with cycle times >10 ms.
PROFINET IRT (isochronous real-time)
This isochronous real-time communication was developed especially for motion control applications. If specific hardware is used, cycle times <1 ms and jitter times <1 µs can be achieved.