Maintenance - ADC HiGain HLU-200 User Manual

150-200-114-03, Issue 03

Maintenance

Alarms. The AHT1U can generate two types of alarms toward the CBA. The first is caused by unplugging the
HLU card after it has been ENTERED. This generates a MJ (Major), SA (service affecting) Eqpt. alarm along
with the "UEQ-Unequipped" message. The second is caused by various alarms within the AHT1U circuit. See
the Alrams section of this manual for AHT1U Alarm details. Any of these HLU alarms cause an MJ, SA, T1
alarm with an "LOS: Loss of Signal" message. The AHT1U supports the following Alarm commands:
1. RETRIEVE STANDING ALARMS (DLP-504)
This command retrieves the following alarm status of an AHT1U
a. Access ID. As above.
b. Severity. Major only.
c. Service Affected. SA (service affecting) or NSA ( non service affecting). Both types of
AHT1U alarms are SA.
d. Type. Eqpt (AHT1U UEQ unit removal) or T1 (AHT1U LOS internal alarm).
e. Message. UEQ or LOS
2. RETRIEVE CONDITIONS (DLP-505)
This command retrieves the same information as the above Retrieve Standing Alarms command,
in addition to providing the Service State (IS, OOS or MT) of the AHT1U.
Performance Monitoring. The AHT1U does not support any of the main Litespan performance monitoring
functions. The AHT1U conducts its own performance monitoring. Access to this performance data is provided
by the AHT1U's on-board maintenance program, which is accessible from its front panel RS-232 port. See the
System Maintenance Menu Screens section of this practice for more details.
Testing. The AHT1U does not support any of the Litespan initiated loopbacks. However, the AHT1U
maintains a family of loopbacks that can be initiated from its RS-232 front panel maintenance port and inband
codes. Although Figure 3 shows that metallic access to the HDSL loops is provided through the two narrow
band test loops on pins 35 through 38 under control of two test relays, this option is not supported by the
Litespan 7.1.x software. Enhanced versions of the Litespan software will support this test access. The AHT1U
supports the following Testing commands:
1. REMOVE FROM SERVICE (DLP-572)
This command allows an AHT1U that is In Service (IS) to be placed into its MT (Maintenance
Test) state for generic testing. While in this state, no AHT1U alarm states are recognized by the
CBA. The AHT1U can be replaced and intrusive tests can be performed without generating a
CBA alarm.
2. RESTORE TO SERVICE (DLP-573)
This command restores an AHT1U that is in its MT state to its IS state.
HLU-200 List 1D November 22, 1996 7