Section 150-388-124
Revision 01
Page 6
5. SYSTEM OPTIONS
5.01
The HLU-388, List 2D contains a non-volatile
RAM (NVRAM) which stores the system options
settings. No dip-switches or jumpers are required to
configure these system options. They are set via push
buttons on the front panel or through the RS-232 interface
or from the Network Management interface. The System
Settings are retained if shelf power is lost or if the HLU-
388, List 2D is unplugged. Table 1 lists the HLU-388, List
2D System Options. Figure 10 and Figure 22 illustrate the
same options on the HLU-388, List 2D non-doubler and
doubler System Settings Menu screens, respectively. In the
System Settings Menu (which is identical for both non-
doubler and doubler applications), the settings shown
represent the factory default settings.
5.02
The Setup momentary push buttons (Mode and
SEL) are used to set the options from the HLU-
388, List 2D front panel. To initiate the Options Setting
mode, press the Mode button, for at least one second, but
less than three seconds, and release. The message displayed
on the front panel alternates between the first system
parameter and its current setting. Pressing the SEL button
scrolls the display (one at a time) through all possible
settings of the parameter being displayed. After the desired
setting has been selected, press the Mode button. This
updates the currently displayed mode to the selected setting,
then selects the next configurable parameter. After the last
parameter has been selected, the display shows “CONF NO
(Confirm? (Yes/No)).” If the Mode button is pressed at this
time, none of the changed parameters are installed. If the
SEL button is pressed, a “YES” message is displayed, and
the selected changes are installed. In either case, the
display returns to its normal mode. The display also returns
to its normal mode, without installing any new changes, if,
after 30 seconds, neither button is pressed.
5.03
All 14 user options can be set to the factory default
values by pressing the SEL button for six seconds
until the message “DFLT NO” appears. To set the default
values, press the SEL button while the “DFLT NO”
message is displayed. “DFLT YES” will be displayed,
indicating the factory default values are now in effect. To
terminate the Default 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.
5.04
Pressing the Mode button for three or more
seconds causes the display to scroll through the
HLU-388, List 2D software version number, its list number,
the type of frame pattern being received from the DSX-1,
the line code setting of the HLU-388, List 2D, and all 14
options settings. The line code parameter is the actual DS1
line code being received by the HLU-388, List 2D when the
DS1 code pattern is set to Auto. Otherwise, the line code
parameter mimics either of the other two line code settings,
AMI or B8ZS, and is not determined by the received line
code.
5.05
The DS1 line code option should always be set to
conform to the type of T1 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 T1 circuits whose line codes are
not known or may be both AMI and B8ZS), because it has
the following two limitations:
1. The Auto mode induces one BPV in the T1 bit
stream whenever it switches from AMI to
B8ZS.
2. The Auto mode allows each HiGain end (HLU
and HRU) to set its DS1 mode to the code it is
receiving at its local T1 input port. This makes
each unit’s code independent of the T1 code,
which is being received at the distant T1 input
port. Thus, if the line codes being received by
HiGain are different in each of the two T1
directions, the HiGain T1 output codes will not
match their respective T1 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 zeroes.
5.06
The following three user options can only be set
via the RS-232 terminal interface: Circuit ID, DS0
Blocking, and Margin Alarm Threshold.
