HDSL4 for General Distribution Installation and Maintenance Practice
Control Port Operation
61223HDSL4L2-5C
47
Chronic Circuit Guidance
Selecting the Chronic Circuit Guidance option displays the Chronic Circuit Problems screen
(
). This screen provides general information about circuits with bad splice connec-
tions as well as a menu to the Bad Splice Detection feature.
Splices that are varying in impedance cause the HDSL transceiver to see a reduced and/or
fluctuating signal quality (margin). The HDSL transceiver attempts to track these changes,
but when the changes become too severe, errors or loss of synchronization result. This is
reflected by the symptoms described on this screen.
If a circuit meets the criteria listed on the screen then the possibility of an impedance-varying
splice should be considered.
Figure 43. Chronic Circuit Problems Screen
To access a particular menu item, press the number associated with that item, and press
E
NTER
. The menu options are as follows:
•
•
•
Press ESC to return to previous menu
Chronic Circuit Problems
Field experience has shown that many chronic circuit failures are due to
bad splices. These type circuits generally have the following symptoms:
- Wire pairs pass all electrical tests and meet deployment guidelines.
- Large margin fluctuations will occur on the suspect pair. This can be seen
on the Detailed Status Screen. (Min & Max margins differ by > 6 dB)
- Pairs experience errored seconds (ES,SES,UAS) and/or loss of sync (LOS).
- The bad splice will most severely impair the unit closest to the splice.
This HDSL unit has the ability to test for bad splices. This detection
should be used as a last resort after all other loop testing has been
done. The detection is an approximation which can point the technician
to the general area of the suspect splice.(+/- 275 ft). For best
results, re-splice all splices close to the indicated trouble.
1. View Splice Results
2. View Histogram Screen
3. Reset Splice Detector
