
Provisioning
150-231-184-05, Revision 05
24
October 25, 1999
HLU-231 List 8D
Margin Alarm Threshold Option
To set the Margin Alarm Threshold:
1
Select
from the System Settings Main Menu screen.
2
Enter the desired minimum acceptable alarm threshold from the 0 to 15 dB range. This causes a system alarm
to occur if either the margin on HDSL Loop 1 (MAL1) or Loop 2 (MAL2) drops below the selected threshold
value.
HDSL Line Voltage Options
The PWRF option has four settings for HDSL line power feed: DIS, LOW, AUTO, and HIGH.
•
DIS
disables any voltage from being applied to the HDSL cable pairs. It is useful to prevent craft personnel
from being exposed to the HDSL line voltage when they are working on the cable pairs.
•
LOW
limits the HDSL simplex voltage to -140 V maximum. This is the standard voltage used in all
non-doubler applications and has no effects in these applications. It can be chosen to limit line-powered,
single-doubler circuits or locally-powered, two-doubler circuits up to -140 V, if the appropriate HiGain
products (HDU-409, HDU-404 or HDU-407 and HRU-402 or HRU-411) are used along with the
HLU-231 List 8D. These HiGain units are the only ones that have sufficiently low power consumption to
allow their doubler circuits to be line-powered from -140 V. The HRU-411 must have the CPE power option
disabled if it is used in a -140 V doubler circuit.
•
AUTO is the conventional mode in which the HLU automatically maintains the HDSL line voltage at -140 V
maximum for non-doubler applications and
112 V for doubler applications.
•
HIGH
forces the HDSL line voltage to its high ±112 V level for applications. It is needed to allow the HLU
to power circuits that are providing power to remote Personal Communication Systems (PCS) sites.
Since the margin can never drop below zero, choosing
(zero) for the margin threshold turns
the margin alarm off.
If the HLU-231 List 8D is used with the HRU-411 to power PCS sites, PWRF option should be set
to AUTO. This causes the HLU to automatically detect the need to switch to the HIGH power feed
mode when it receives a request from the HRU to do so.
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