9
Section 61246001L2-5, Issue 2
61246001L2-5B
At the Current System Status screen, type “Z” to reset
the current performance registers to zero on the
Current System Status and Performance History
screens. A prompt will require user confirmation
prior to executing the zero register function
Figures 10 and 10A consolidate current information
for the HDSL, DSX-1, and DS1 interfaces. A key to
the information provided is found in the center of the
screen. Arrows indicate the key applies to both the
HTU-C M and HTU-R.
LOSS
Pulse Attenuation Measurement
2
SYNC
HDSL Loop 1 and Loop 2 Sync
Status
ES
15M/24H Errored Seconds
3
SES
15M/24H Severely Errored Seconds
3
UAS
15M/24H Unavailable Seconds
3
An indication of Pair Reversal (if present) is given at
the bottom of the first key column. Status and
configuration information for the DS1 and DSX-1
signals is located in the center of the screen near the
bottom.
FRAME
T1 Framing Format selected
CODE
T1 Line Code selected
LBO
Line Build-Out selected (for DSX-1);
Customer Signal of 0 or -15 dB (for
DS1)
NIU
Network Interface Unit enabled?
BPV
Bipolar Violations detected
(DSX-1 and DS1)
ES
Errored Seconds (DSX-1 and DS1)
SES
Severely Errored Seconds (DSX-1
and DS1)
UAS
Unavailable Seconds (DSX-1 and
DS1)
Alarms
Lists current alarm condition status
A measure of signal quality for each HDSL loop is
displayed in graphic form on the bottom of the screen.
2
LOSS is typically several dB less than the insertion loss measured at 200 kHz. The LOSS measurement is a
better indication of the loop’s attenuation of the 2B1Q signal than the insertion loss measured at a single
frequency. ADTRAN HDSL can operate on cables with an excess of 30 dB LOSS.
3
The first number is for the current 15-minute period and the second is the current 24-hour period (Loop 1 and
Loop 2 numbers are displayed).
The measure is from 0 (poor signal quality) to 9
(excellent signal quality). Guidelines for interpreting
the indicators are given below.
0
Noise margin is
≤
0 dB (
≈
10
-7
BER)
1-8
Margin measurement above 10
-7
BER in dB
9
Margin is
≥
9 dB (excellent quality) above
10
-7
BER
Predicting performance based upon signal quality
varies with each loop. Generally, a noise margin of 0
or higher will support a bit error rate of better than
10
-7
. ADTRAN has defined the following as
guidelines that correspond to the operation of the
HTU-C faceplate LEDs labeled LP1 and LP2.
Margin < 0 ( Red)
Poor Loop Quality
0
≤
Margin
≤
2 (Yellow)
Marginal Loop
Quality
Margin > 2 (Green)
Good Loop Quality
Figures 12 and 13 depict the HDSL Loopback and
Self Test Option screens. Loopbacks and Self-Test
may be evoked or terminated using these screens. A
status of current loopback conditions is also provided.
Figure 14 displays current provisioning settings and
allows for changing the system configuration.
Provisioning changes are only allowed at the CO end
of the circuit. Provisioning changes made through this
screen override the manual switch settings. The unit
retains the last provisioning changes to determine its
operating mode.
The Troubleshooting Display, shown in Figure 15,
graphically presents an HDSL circuit. The unit
