Section 150-388-124
Revision 01
Page 7
5.07
The Circuit ID option is set by choosing the
H option from the terminal Main Menu screen (see
Figure 7 for non-doubler applications and Figure 16 for
doubler applications). The message “ENTER CIRCUIT
ID#:” (24 characters max) follows the “H” selection. Press
Enter after entering the chosen set of alpha-numeric ID
characters; choose C to confirm. Note that if more than 24
characters are entered, a “Beep” is emitted, and only the
first 24 characters are accepted. The ID appears in all
HLU-388, List 2D screens, as shown in Figures 7 through
14 for non-doubler applications and Figures 16 through 34
for doubler applications. The ID does not appear on the
HRU-412 screens when the maintenance port is accessed at
the remote unit. Note that the Circuit ID can not be set to
its factory setting (all blanks) setting when the DFLT setting
option is utilized (see paragraph 5.03 on the previous page).
5.08
To set the DS0 Blocking option, from the Main
Menu screen, press C to select the System Settings
Menu screen. The menu shown in Figure 10 (for non-
doubler applications) and Figure 22 (for doubler
applications) appears. Press B, as shown in parentheses of
the DS0 blocking selection. The DS0 channels are blocked
or unblocked by entering each channel number. Multiple
channels can be selected by inserting a space between each
entry. After all the new settings have been made, press E
(“Exit”) and C (“Confirm”). The new choices are now
installed. Also, all blocked channels are temporarily
“unblocked” for all HiGain system loopback tests. This
allows the standard full bandwidth T1 loopback tests to be
performed.
5.09
To set the Margin Alarm Threshold, select G from
the System Settings Menu screen. Enter the
desired minimum acceptable alarm threshold from the 0 to
15 dB range. This causes a minor alarm to occur if either
the margin on HDSL loop 1 (MAL1) or loop 2 (MAL2) of
any span drops below the selected threshold value (see
Section 4). Since the margin can never drop below 0,
choosing 0 for the margin threshold turns the margin alarm
off.
5.10
Other system settings are set by using a terminal in
a similar manner. Enter the key represented by the
letter in parentheses of the parameter to be changed. Each
entry of this letter scrolls the parameter to its next value.
Hit the Enter key after making each selection. After all
selections have been made, press E to “Exit” and C to
“Confirm” the changes. This activates the new choices and
returns control to the Main Menu screen.
5.11
The new T1 transceiver chip in the List 2D allows
the unit to process both B8ZS and AMI code
inputs, regardless of the DS1 code setting (AMI or B8ZS).
Earlier units caused input BPV, if B8ZS patterns were
processed while in the AMI mode. When the newer units
are in the AMI mode, they can receive B8ZS but can only
transmit AMI. For this reason, mixed systems (those
consisting of both HLU-388, List 2D and older Lists 1, 2, 3,
3A and 4 HRU-412 units) will respond differently in each
direction for B8ZS inputs when in their AMI modes.
5.12
The Self-test mode, which occurs when both
HDSL loops are not in-sync, has been enhanced to
include the input DS1 transceiver chip in the self-test
procedure. This process can cause the Alarm Indicating
Signal (AIS) pattern, which is normally transmitted from the
HLU-388, List 2D during these out-of-sync intervals, to
exhibit occasional BPVs.
5.13
The HAIS option provides two selections (1LP
and 2LP) for the T1 transmit outputs at both the
HLU-388, List 2D and HRU-412 for HDSL loss-of-sync
conditions. The “1LP” selection causes the AIS pattern to
be transmitted at both T1 outputs when either of the two
HDSL loops experience a loss-of-sync (LOSW) condition
or when a margin alarm occurs. This choice causes the 12
channels on the surviving loop to be lost as they are
replaced by the AIS pattern. However, it allows both down
and upstream equipment to be made aware of the loss of
one HDSL loop or a loop with low margin. The 1LP
selection is the preferred setting to be able to initiate an AIS
state with just one conductor open in either of the HDSL
pairs. Short loops, below about 16 dB of loss at 200 kHz,
can remain in-sync with one conductor open. Since the loop
is still in-sync, no LOSW condition occurs. However, the
margin on a one-conductor loop drops from 5 to 10 dB.
Thus, if the margin alarm is set to 5 dB below the normal
margin at turn-up, when one conductor opens, a minor
alarm occurs and causes the AIS condition. This alerts the
maintenance personnel of the problem. The “2LP” choice
requires both HDSL loops to be out-of-sync (LOSW) before
the AIS signal is transmitted. This choice preserves the
integrity of the 12 surviving channels when just one loop is
lost.
5.14
All user options that affect the operation in both
the HLU-388, List 2D and HRU-412, (such as
HAIS, SAIS and DS0 blocking) are not available in older
versions of the HRU-412, Lists 1, 2, 3, 3A, and 4 that do
not support these newer options.
