Section 150-319-124
Revision 03
Page 5
4. ALARMS
4.01
Pin H is the HLU-319 minor alarm (MNRALM)
output pin, which replaces the Local Loss of Signal
alarm on normal High Density (3192) repeaters. Its
normally floating output can connect to pin 1 of the
1184 or 3192-9F Alarm Card in position 29 of the High
Density (HD) shelf. This pin must never be taken
above +5 V or below -60 V. The HLU-319 forces pin
H to +5V (maximum of 10 mA) for any of the
conditions listed below. (The accompanying front
panel message is listed below in bold letters.) More
than one alarm condition can exist at any given time,
but only one message can be displayed. For multiple
alarms, only the highest priority alarm is displayed.
The alarms are listed in their order of priority:
1. ALRM LOSW: Either HDSL loop lost sync
2. ALRM LLOS: Loss of HLU DSX-1 input
signal
3. ALRM RLOS: Loss of HRU DSX-1 input
signal
4. ALRM TLOS: A user option that causes
the loss of the HRU DS1 input from the CI
to initiate a logic loopback in the HRU.
5. ALRM H1ES: HDSL loop 1 has exceeded
the 24-hour user-selected Errored Seconds
CRC threshold. If both H1ES and H2ES
occur, only H1ES is displayed on the front
panel.
6. ALRM H2ES: HDSL loop 2 has exceeded
the 24-hour user-selected Errored Seconds
CRC threshold. If both H1ES and H2ES
occur, only H1ES is displayed on the front
panel.
7. ALRM DS1: The total number of bipolar
violations (BPV), at either the HLU or the
HRU DS1 inputs, have exceeded the 24-
hour user-selected threshold.
8. ALRM MAL1: The margin on HDSL loop
1 has dropped below the minimum
threshold value set by the RS-232 terminal
Margin Alarm Threshold; as described in
Section 5.
9. ALRM MAL2: The margin on HDSL loop
2 has dropped below the minimum
threshold value set by the RS-232 terminal
Margin Alarm Threshold; as described in
Section 5.
4.02
Pin H, MNRALM, remains at +5V for the
duration of the alarm condition. If the Wescom 1184
Alarm Card is installed in the shelf, its LOS LED lights
for every MNRALM. The HLU-319’s Status LED
flashes red for the duration of a minor alarm condition.
Alarms 4 and 5 can be inhibited by selecting “None”
for the ESAL system option (see Section 5 for System
Settings information). The MAL(X) alarm can be
DISabled by setting the margin alarm threshold to 0.
The minor alarm can be retired by executing the
Alarm CutOff (ACO) option. This is accomplished by
pressing the SEL button on the front panel. This turns
the alarm off and replaces the ALRM message with
the ACO message. However, the second part of the
ALRM message, which defines the cause of the
alarm, remains. Both messages remain until the
alarm condition clears or another alarm occurs.
Disabling the ALM also retires an ACO condition.
4.03
Setting the ALM option to DIS(able) only
prevents the minor alarm output alarm bus on pin H
from being activated on a minor alarm event. The
Status LED still flashes red and the ALRM message is
still displayed.
4.04
The HLU-319 Pin 10, Fuse Alarm is driven to
-48 V whenever its on-board fuse opens. It emulates
the function of the Fuse Alarm output from Pin 10 of
normal HD repeaters. The Pin 10 signal is connected
to Pin 5 of the 1184 Alarm Card (slot 1 in HD shelf)
and causes the 1184 Fuse ALM LED to light when the
Pin 10 signal is activated. Its normally floating output
must never be driven above ground or below -80 V. It
can sink a current of 10 mA.
4.05
Pin 7 is the NMA serial bus. It is provided for
access to the HMU-319 shelf controller card that will
provide shelf management. Whenever the HLU-319 is
under management, it periodically displays the MNGD
message on its 4 character front panel LED display.
Some of the features of the HLU-319 are affected
when it is under management. Consult the
management units practice for more detail.
4.06
The HLU-319 does not support the BPV
function (Pin E) of normal HD repeaters.
4.07
The HLU-319’s front panel tri-color Status
LED has the following states:
•
GREEN - Normal Operation
•
FLASHING GREEN - HDSL Acquisition
•
FLASHING RED - Minor Alarm (for
conditions, see Section A Paragraph 4.02)
•
RED - Fuse Alarm
•
YELLOW - Self-test in process or an HLU
Loopback in effect (CREM or NLOC)
•
FLASHING YELLOW - HLU in Armed state
