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Monitoring, History and Diagnostics
Maximum Power Consumption
Maximum power consumption is the total power that the COLU consumes or draws from its -48 Vdc COTS power
source. This parameter is needed when the COLU is located remotely from its serving CO. It determines the
battery capacity required to maintain an 8-hour standby battery reserve for emergency situations. This limits the
maximum number of line units in a remote enclosure.
Maximum Current Drain
Maximum current drain is the maximum current drawn from the COTS power supply when it is at its minimum
voltage (-42.5 Vdc). This determines the COTS fusing requirements.
M
, H
ONITORING
COLUs provide extensive real-time, non-disruptive monitoring of HDSL transmission performance parameters
for all units in a circuit. PG-Plus allows user-selectable threshold settings for performance monitoring
measurements. This allows alarms to be activated at the designated threshold setting. Performance of the user
interface ports is also monitored. Monitored parameters include the following:
•
HDSL
•
Interface
•
Major Alarm Relay
•
Loopbacks
•
Test Jacks
Performance Parameters
Based on the monitored parameters, the COLUs derive the following performance parameters:
•
MAR - A measure of the ratio of signal power to noise power, in dB, at a receiver point. A value of 0 dB
means that the predicted transmission BER is equal to 10
BER is equal to 10
HDSL CRC-6: A 6-bit word in every HDSL frame, representing a calculation based on all the bits in that
frame. Any mismatch at the receiver, between the received CRC-6 and the one calculated, based on the
received data in the frame, indicates that one or more bits were received in error. The units use this parameter
to derive the HDSL ES performance parameter.
•
LOSW - The COLU has detected an error in one or more bits in six consecutive HDSL SYNC words. Two
consecutive SYNC words must be received without error to clear this condition. A LOSW condition generally
indicates the loop is down, thus data cannot be transmitted. The COLU use this parameter to derive UAS
performance parameter.
•
HDSL ES - An interval of 1 second during which at least one error is detected at the incoming HDSL port or
there is an LOSW condition.
•
HDSL UAS - An interval of 1 second during which a loop is down.
4
D
ISTORY AND
IAGNOSTICS
Noise margin, pulse attenuation, ES, UAS
ES, SES, UAS, BPV seconds
Form-C relay contacts (NO, NC, C). Fail-safe operation
Local interface loopback, local HDSL loopback, remote loopback
Bridge jack on the front panel
-10
. The Main menu status display of the console continuously updates the margin value.
January 6, 2003
-7
, a value of 6 dB means the predicted transmission
SCP-PLL722-010-04H
PLL-722 List 1
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