Revision 01
June 12, 1997
Section 150-441-124
HiGain HLU-D41
PairGain Engineering - Plant Series
Page 7
See the PairGain Technologies HiGain-1 FT1 Remote Unit, Model HRU-512, Issue 1 Technical
Practice (Part No. 150-512-100-02) for further information.
5.4
Power Conversion.
The HLU-D41 contains two separate power converters. The linear regulator
converts the D4 channel bank dc power (+5 Vdc and -12 Vdc) to logic power for the HLU-D41
circuits. The line power supply converts the D4 channel bank dc power (-48 Vdc) to a -200 Vdc feed
to power the HRU-512.
5.5
A Pulsecom 325A Power Converter, or equivalent, supplies 5A at +5V, allowing up to 11 HLU-D41
units per D4 channel bank.
The 325A D4 channel bank power converter supplies 3A at +5V. That leaves 1.8A for the 48
channel slots or 37mA per slot. This translates to 1.8/.325A or a maximum of five (5) HLU-D41
units per D4 channel bank (two to three units per digroup).
The PCU SLC-96 power converter supplies 3.2A at +5V. This leaves 2A for the 48 dual channel
slots, which translates to 2/.325 or a maximum of six (6) HLU-D41 units per SLC-96 channel bank.
If the enhanced PCU 325A converter, which supplies 5A is used, a maximum of 12 HLU-D41 units
per SLC-96 channel bank can be used. Apply these same rules to calculate the maximum number of
HLU units per channel bank for channel bank power supplies with different capacities.
5.6
Front Panel LCD Power Saving Timer.
The four-digit front panel LCD is activated when
power is initially applied to the line unit. To conserve power, the display remains active for only
four minutes if neither the Mode or Choice setup buttons are pressed. The use of either button re-
activates the four-digit display and restarts the four minute power saving timer.
6. Alarms
6.1
Front-Panel Alarm Displays.
The HLU-D41 Status LED flashes red for the duration of a minor
alarm condition. Table 5 lists the HLU-D41 alarms that can be displayed in the front-panel LCD
(these alarm conditions display in the "Alarms" field of the View Span Status screen as well). The
message "ALRM" appears one time in the front panel LCD prior to the display of the alarm
condition message.
The front panel message that accompanies each alarm condition is listed in the "Alarm" column.
Since more than one alarm condition can exist at any time, but only one message can be
displayed, only the highest priority alarm is displayed if more than one alarm condition exists.
The alarms are listed in their order of priority.
Table 5. Alarm Conditions
Alarm
Reason
LOSW
The HDSL loop has lost sync.
MOOS
The channel bank is out of sync.
RLOS
Loss of HRU-512 DS1 input signal.
HES
The HDSL Loop has exceeded the 24 hour user-selected Errored-Seconds Cyclic
Redundancy Check (CRC) threshold (set at front panel using the ESAL option or at the
System Settings menu using ES ALARM THRES).
DS1
The total number of Bipolar Violations (BPV) at the HRU-512 DS1 input has
exceeded the 24-hour user-selected threshold (set at the front panel using the DS1
option or at the System Settings menu using DS1 LINE CODE).
MAL
The margin on the HDSL Loop has dropped below the minimum threshold value set
using the Margin Alarm Threshold option as described in Section 18.12.
