Section 150-611-100
Revision 02
Page 6
7.12
In Central Office locations, the maximum
power dissipation for open faced, natural
convection cooled mountings is limited to 120 W /
sq. ft. per Section 4.2.3 of the NEBS standard TR-
NWT-000063. The footprint of a 13 slot 23” HLU-
611 shelf is 7.024 sq. ft. Thus the maximum bay
dissipation is limited to 840 Watts. At 104 Watts per
shelf, this limits the number of fully loaded HLU-611
shelves to 8 per bay. Note that this is a worse case
situation in that it assumes the entire Central Office
is subjected to the maximum power density.
Conditions other than these worse case ones would
permit increasing the number of shelves per bay
without jeopardizing the C.O.’s thermal integrity.
7.13
The thermal loading limitations imposed
when using the HLU-611 in CEVs or other
enclosures are determined by applying the HLU-
611’s power parameters to the manufacturer’s
requirements for each specific housing.
7.14
The Maximum Power Consumption is the
total power that the HLU-611 consumes or
draws from its -48 V shelf power source. This
parameter is needed when the 611 is located remote
to its serving C.O. It determines the battery capacity
required to maintain an 8 hour stand-by battery
reserve for emergency situations. It thus limits the
maximum number of plugs per remote enclosure.
Use the above data to perform this analysis on a
case by case basis.
7.15
The Maximum Current Drain is the
maximum
current drawn from the shelf power
supply when it is at its minimum voltage (42.5 V).
This determines the shelf fusing requirements.
HLU-611 shelves are fused at 10 A. A fully loaded
shelf of 13 HLU-611s draws 5.5 A in the worst case.
This is well within the 10 A fuse limit.
7.16
A 9-pin (RS-232) DB-9 connector (see
Figure 3), is provided on the front panel.
This connector provides access to HiGain-2’s
maintenance, provisioning and performance
monitoring interface. A very basic interface is
available via a ‘dumb terminal’. Figures 7 through
13 show the menu selections that are available from
the terminal. The port is configured as DCE with 8
data bits, one stop bit and no parity. Striking the
SPACE bar several times invokes autobaud from
1200 to 9600 bps.
7.17
The normally open alarm contacts available
across pins 20 and 21 comprise the HLU-
611’s Minor Alarm output. The ALM option must
be disabled (DIS) when using the Kentrox 220 T-
Term shelf. This is required to resolve a conflict
between the HLU alarm relay output and the
Kentrox external equalizer output. Both use the
same pins, 20 and 21. These alarm contacts close
for any of the following alarm conditions. Note that
the front panel message which accompanies each
alarm condition is shown in bold letters before each
alarm condition. Since more than one alarm
condition can exist at any given time but only one
message can be displayed, the alarms are listed in
their order of priorities. Only the highest priority
alarm is displayed if more than one alarm condition
exists.
1) ALRM LOSW: The VHDSL loop loses sync.
2) ALRM LLOS: Loss of the HLU T1 input signal.
3) ALRM RLOS: Loss of HRU T1 input signal.
4) ALRM HES: VHDSL Loop has exceeded the 24
hour user-selected Errored-Seconds (CRC)
threshold.
5) ALRM DS1: The total number of bipolar
violations (BPV) at the HLU and HRU T1 input
have exceeded the 24 hour user-selected
threshold.
6) ALM MAL: The margin on the VHDSL Loop has
dropped below the minimum threshold value set
by the dumb terminal MARGIN ALARM THRES;
as described in Section 8.
HLU-611
DCE
FEMALE
MALE
2
5
3
2
5
3
RD (RECEIVE DATA)
TD (TRANSMIT DATA)
GND
DB9
DB9
DTE
DTE
TERMINAL
TERMINAL
3
2
7
DB25
Figure 3. DB-9 Pin-outs.
