9. PROFINET IRT: isochronous mode for axis control

9.1 Announcing an isochronous real-time solution

At the Hanover Fair in April 2003, PROFIBUS International announced the development of IRT (Isochronous Real Time Ethernet) technology. This new technology improves the performance of industrial communication, particularly for position control functions, where drive axes need to be synchronized with very high accuracy. With IRT, more than a hundred drive axes can be synchronized in less than 1 ms, with jitter of less than 1 µs, or even several hundred axes in the case of modular machine groups. Current solutions, based on open fieldbuses, specific drive buses, conventional Ethernet and even software-implemented real-time Ethernet, can manage a maximum of 30 to 40 drives in times of the order of several milliseconds.

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