ABB Relion 670 Series Technical Reference Manual page 74

Section 4
Basic IED functions
68
Synchronization via Built-in-GPS
The built in GPS clock modules receives and decodes time information from the
global positioning system. The modules are located on the GPS time
synchronization Module (GTM).
Synchronization via binary input
The IED accepts minute pulses to a binary input. These minute pulses can be
generated from, for example station master clock. If the station master clock is not
synchronized from a world wide source, time will be a relative time valid for the
substation. Both positive and negative edge on the signal can be accepted. This
signal is also considered as a fine time synchronization signal.
The minute pulse is connected to any channel on any Binary Input Module in the
IED. The electrical characteristic is thereby the same as for any other binary input.
If the objective of synchronization is to achieve a relative time within the
substation and if no station master clock with minute pulse output is available, a
simple minute pulse generator can be designed and used for synchronization of the
IEDs. The minute pulse generator can be created using the logical elements and
timers available in the IED.
The definition of a minute pulse is that it occurs one minute after the last pulse. As
only the flanks are detected, the flank of the minute pulse shall occur one minute
after the last flank.
Binary minute pulses are checked with reference to frequency.
Pulse data:
• Period time (a) should be 60 seconds.
• Pulse length (b):
• Minimum pulse length should be >50 ms.
• Maximum pulse length is optional.
• Amplitude (c) - please refer to section
Deviations in the period time larger than 50 ms will cause TSYNCERR.
1MRK 505 208-UEN B
"Binary input module (BIM)".
Technical reference manual