800-357-104-01, Revision 01
Troubleshooting and System Testing
HMS-357 List 4 and List 5
September 29, 2000
71
L
INE
U
NIT
T
ESTING
Once the line unit is installed, verify that it is operating properly. To do this, monitor the following:
•
Status LED
•
Messages reported by the front-panel display.
Verification without a Downstream Device
If there is no downstream device installed:
Verification with a Downstream Device
If a downstream device has been installed:
Step
Procedure
1
Verify that the line unit powers up. The front-panel display illuminates and reports status messages.
2
Verify that the line unit attempts to communicate with downstream devices (status LED flashes red). Even if a downstream
device is not present, the following events should occur:
•
The front-panel display reports various four-character status messages.
•
The line unit again attempts communication until a downstream device is detected.
Step
Procedure
1
Verify that the line unit powers up. (The front-panel display illuminates and reports various status messages.)
2
Verify that the line unit attempts to communicate with downstream devices (status LED flashes red):
•
If downstream devices are successfully identified and the HDSL2 loop synchronizes, the line unit status LED lights a
steady green. The line unit reports normal margin messages on the front-panel display.
•
If downstream devices are not successfully identified, the line unit reports status messages. The line unit attempts
communication again and reports four-character status messages until a downstream device is detected.
3
If downstream devices are not successfully identified, the line unit reports four-character status messages. The line unit
attempts communication again and reports four-character status messages. The line unit repeats this cycle until a
downstream device is detected.
4
If downstream devices are not successfully identified, the line unit reports status messages. The line unit attempts
communication again and reports four-character status messages until a downstream device is detected.
5
If a remote unit is installed, verify that the last span synchronizes normally. The line unit status LED should light a steady
green and the front-panel display should report normal margin messages.
6
Verify that a valid DS1 signal has been applied to the line unit and the remote unit.
•
If no DS1 signal is being applied to either the line unit or the remote unit inputs, then the appropriate DS1 alarms (LLOS
or RLOS) display on the front panel and the status LED flashes red.
•
If a valid DS1 signal is being supplied to the line unit and remote unit, then DS1 alarm indications should be absent and
the status LED lights a steady green.
7
If you need more information on managing line units, see the technical practice for the respective unit.
If you need more information on managing alarms, see
.
