Distributed Clock
The distributed clock represents a local clock in the EtherCAT slave controller (ESC) with the following characteristics:
- Unit 1 ns
 - Zero point 1.1.2000 00:00
 - Size 64 bit (sufficient for the next 584 years; however, some EtherCAT slaves only offer 32-bit support, i.e. the variable overflows after approx. 4.2 seconds)
 - The EtherCAT master automatically synchronizes the local clock with the master clock in the EtherCAT bus with a precision of < 100 ns.
 
For detailed information please refer to the EtherCAT system description.