Section 150-611-100
Revision 02
Page 8
returns to its normal mode, without installing any
new changes, if neither button is depressed for 30
seconds.
8.03
All of the 12 user options can be set to the
factory default values by depressing the
SEL button for six seconds until the message:
“DFLT NO” message is displayed. “DFLT YES” will
be displayed indicating the factory default values are
now in effect. To terminate the DFLT mode without
setting the factory default values, press the MODE
button or do nothing for 30 seconds. The latter
returns the display to its normal state.
8.04
Depressing the MODE button for three or
more seconds causes the display to scroll
through the HLU’s software version number, its List
#, the type of frame pattern being received from the
DSX-1, the line code setting of the HLU and all 11
option settings. See Table 9 for these additional
messages.
8.05
The following three user options must be set
with a dumb or smart terminal: CIRCUIT ID,
DS0 BLOCKING and MARGIN ALARM
THRESHOLD.
8.06
The CIRCUIT ID option is set by choosing
the “I” option from the dumb terminal’s main
menu shown in Figure 6. The message “enter
circuit ID #: 24 characters max” follows the “I”
selection hit the return key after entering the chosen
set of alpha-numeric ID characters. Then chose “C”
to confirm. Note if more than 24 characters are
entered, an error message appears. Simply delete
the excess characters and then hit the return key
once again. The ID appears in all HLU screens as
shown in Figures 7 through 13. The ID does not
appear on the HRU screens when the maintenance
port is accessed at the remote unit. Note that the
Circuit ID is not set to its default (all blanks) setting
when the DFLT setting option is utilized.
8.07
To set the DS0 BLOCKING option first
select the SYSTEMS SETTINGS (“D” choice)
from the main menu. The menu shown in Figure 8
appears. Now enter the letter “B” shown in
parenthesis of the DS0 blocking selection. The DS0
channels are blocked or unblocked by entering each
channel’s number. Multiple channels can be
selected by inserting a space between each entry.
After all the new settings have been made, enter “E”
for exit and then “C” for confirm. The new choices
are now installed. If DS0 blocking is invoked in a
HiGain-2 system that has an earlier HRU that does
not support the blocking option, blocking will only
occur at the DS1 output of the HLU. The HRU’s
DS1 output will not be blocked. Also, all blocked
channels are opened for all HiGain-2 loopback tests.
This allows the standard full bandwidth T1 loopback
tests to be performed.
8.08
To set the MARGIN ALARM THRESHOLD
select “G” from the system settings menu.
Enter the desired minimum acceptable alarm
threshold from the 0 to 15 dB range. This causes a
minor alarm to occur (see Paragraph 7.17) if the
margin on the VHDSL loop drops below the selected
threshold value. Since the margin can never drop
below 0, choosing ”0” for the margin threshold turns
the margin alarm off.
8.09
The other dumb terminal system settings
are
set in a similar manner. Simply enter the
letter in parenthesis of the parameter to be changed.
Each entry of this letter scrolls the parameter to its
next value, hit the enter key after each selection is
made after all selections have been made, enter “E”
and then “C” to the resulting Confirm message. This
activates the new choices and returns control to the
main menu.
8.10
The SELF-TEST mode that occurs when the
VHDSL loop is not in sync includes the
input DS1 transceiver chip in the self test procedure.
This process can cause the AIS pattern, that is
normally transmitted from the HLU during these out
of sync intervals, to exhibit occasional BPVs.
8.11
The DS1 line code option should always be
set to conform to the type of DS1 service,
AMI or B8ZS, being provided by the HiGain system.
The AUTO mode, which can adapt to either AMI or
B8ZS, should only be used in applications that
require it (such as when HiGain acts as a standby
circuit to DS1 circuits whose line codes are not
known or may be both AMI and B8ZS) since it has
the following two limitations. The AUTO mode will
induce one BPV in the DS1 bit stream whenever it
switches from AMI to B8ZS. The AUTO mode
allows each HiGain end, HLU and HRU, to set its
DS1 mode to the code it is receiving at its local DS1
input port. Thus if the line codes being received by
HiGain are different in each of the two DS1
directions (unlikely, but possible) the HiGain DS1
output codes will not match their respective DS1
input codes at the other end. This could cause the
customer’s received data to be AMI instead of B8ZS
and thus violate the one’s density rules by having
excessive zeros.
