Precise Synchronisation in Industrial System Using Ieee 1588 Precise Time Protocol

Abstract

Nowadays there is a frequent demand to increase the quality of synchronization in industrial distributed systems. Node synchronization can be implemented in the Ethernet network using time protocols, e.g. IEEE 1588 Precise Time Protocol (PTP). However, active network components like switches and routers have negative influence on achieved accuracy of synchronization because they affect a packet delay variation in the network. To suppress this effect, special (but expensive) industrial switches, with a packet propagation delay correction, can be used. Another way using either low cost GPS receivers for synchronization of local clocks or a special timing for data transfer is described in the paper. It will allow a cheaper solution that preserves high quality of synchronization. Besides, a device for packet delay measurement (PTP tester) was designed and developed to be possible to evaluate the proposed methods.