Omicron CMC 356, User Manual

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CMC 356-Related Products and Accessories
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9.3.2 CMIRIG-B
Via the CMIRIG-B interface box you can connect devices to the CMC 356
test set that either transmit or receive the IRIG-B time reference signal
(DC level shift protocol B00x). That way, two or more CMC test sets are
synchronized. Furthermore, an optional
CMGPS synchronization unit can
be integrated into the test setup to serve as source of the synchronization
moment or 1PPS signal, respectively.
CMC 356 decodes (when receiving)
or encodes (when transmitting) the IRIG-B protocol. The IRIG-B protocol
extensions required by standard IEEE C37.118 are supported as well.
The most significant functional enhancement of those Test Universe test
modules supporting the IRIG-B time reference is the starting and
synchronizing of
CMC 356 states (signal output) with high accuracy
synchronous to the IRIG-B
1
time reference or PPS/PPX
2
signal,
respectively; for example for PMU synchrophasor tests.
Figure 9-6:
Typical test setup with
CMIRIG-B
(not true to scale)
Requirements:
• CMC 356 standard test set with Ethernet ports.
• IRIG-B source or receiver with 5 V/TTL level; demodulated; DC level
shift protocol (B00x).
1
IRIG stands for I nter R ange I nstrumentation G roup and represents a serial time code format.
2
PPS: pulses per second
PPX: programmable PPS signal (pulse rate, e.g., 1 pulse per minute or one pulse per
10 seconds)
Test signals (e.g., 3 x current, 3 x voltage).
IRIG-B/PPS source, e.g. GPS receiver with IRIG-B output.
IRIG-B/PPS receiver, e.g. protection relay, PMU.
Optional CMGPS synchronization unit (depends on the application).
1
2
3
4
1
2
3
4