Circuit Pack Descriptions
7-68 Issue 8.0 July 2002
Performance Monitoring. 7The IS3 (1.3 STD) circuit pack monitors the following
performance-monitoring parameters:
â– Optical transmit power
â– Loss of signal
â– Loss of frame
â– Bit error rate thresholds
When an incoming IS-3 signal defect from the lightguide cross-connect panel is
detected, the OC3 (1.3 STD) circuit pack inserts STS-1 path AIS in each STS-1
tributary of the STS-3/3c signal (155.52 Mb/s) transmitted toward the OC-48
TRMTR circuit pack.
When an incoming OC-48 signal defect is detected by the OC48 RCVR circuit
pack or an STS-1 loss of pointer is detected by the IS3 (1.3 STD) circuit pack in
the 155.52 Mb/s signal received from the OC48 RCVR circuit pack, the IS3 (1.3
STD) circuit pack inserts STS-1 path AIS in each STS-1 tributary of the IS-3 signal
transmitted toward the lightguide cross-connect panel.
When an internal fault is detected, the IS3 (1.3 STD) circuit pack inserts STS-1
path AIS in each STS-1 tributary of the STS-3/3c signal transmitted toward the
OC48 TRMTR circuit pack and in the IS-3 signal transmitted toward the lightguide
cross-connect panel.
Power Circuitry 7
The IS3 (1.3 STD) circuit pack receives two sources of −48 volts that are diode
OR'd, fused, and filtered. A modular DC-to-DC power converter produces +5 volts
used on the circuit pack.
If the IS3 (1.3 STD) circuit pack detects the failure of the onboard fuse or power
converter the red FAULT LED will light. If the fuse or power converter fails, the
LNCTL circuit pack provides +5 volts to light the FAULT LED on the IS3 (1.3 STD)
circuit pack.