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standard protocol IEC 60870-5-103, IEC 61850 or modified Modbus RTU protocol
are available. If better accuracy is required, REF 542plus can be synchronized using
the dedicated IRIG-B optical input port and a GPS master clock. The accepted
timeformats are IRIG format B 000, B002 and B003. The Fig. 4.7.-1 shows the time
distribution architecture for the synchronization.
A050501
Fig. 4.7.-1
Synchronization of the internal clock by a GPS master clock
4.8.
Interface to the primary process
The REF 542plus offers a flexible interface to the primary process which is
described in the following sections.
4.8.1.
Analog inputs
REF 542plus switchbay protection and control unit is designed for connecting to
non-conventional current and voltage sensors as well as to instrument transformers.
At most 8 analog input channels are available. Due to their linear characteristic,
modern current and voltage sensors provide greater accuracy and reliability in signal
measurements. Compared to instrument transformers, the new sensors have the
following advantages:
*
Higher linearity
*
High accuracy
*
Compact dimensions
*
Wide dynamic range
*
Easy integration in the panels
Multifunction Protection and Switchbay Control
Unit
Technical Reference Manual
REF 542plus
REF 542plus
1MRS755859