December 18, 2008 – To achieve optimum automation synchronization of large production lines and factories, Beckhoff Automation released the EL6688 EtherCAT Terminal. The EL6688 terminal permits extremely precise cross-factory and cross-site synchronization according to the IEEE 1588 standard.

Using the EL6688, different machines, system components or production lines can be accurately synchronized with each other or with an external grandmaster clock via GPS or DCF77 receivers. In this way, a high-precision, technology- and vendor-independent global timebase is available that can be used for time-stamping of measured data, for example.

With the distributed clocks, all devices in an EtherCAT system can be synchronized with a tolerance of less than 100 ns. The EL6688 EtherCAT Terminal permits synchronization with different networks across sites. This applies to different production lines, for example, which have to be synchronized with microsecond precision. The system utilizes the control accuracy of distributed clocks and the standardized synchronization interface in the EL6688. Synchronization to an external event is always the same, irrespective of whether the external application uses EtherCAT, IEEE 1588 or a digital input.

The EL6688 EtherCAT Terminal supports the Ethernet-based IEEE 1588 protocols PTPv1 (IEEE 1588-2002) and PTPv2 (IEEE 1588-2008).

The EL6688 is an IEEE 1588 clock (ordinary clock), which, from the perspective of the higher-level master (grandmaster), operates as a slave or supplies the connected EtherCAT Terminals (slaves) as a master via distributed clocks. The EL6688 terminal can be located at any point within an EtherCAT Terminal network.