For high-performance motion control applications, such as precise coordination of hundreds of axes with microsecond precision, Profinet includes an isochronous real-time channel. Profinet IRT (Profinet Isochronous Real-Time) is used for closed-loop control of a system, where the control (both the set-point and feedback) for multiple devices occurs during the same sample period.
With its superior speed, DSProfinet IRT allows any generic Ethernet interface to communicate with a Profinet IRT network.
Certainly other Ethernet protocols in motion control today operate on a regularly occurring interval basis. So one may ask, what is special about Profinet IRT. The guiding factor that sets Profinet IRT apart from other real-time, cyclic protocols is the concept of “jitter”. The jitter is defined as the time fluctuation in the start of the interval. For the controller in the network to do IRT control, it must maintain a jitter under 1µs.
DSProfinet comes in stand-alone or PCI form.