PairGain 150-1504-14, Quick Installation Manual, Page: 8 / 20

Section 350- 431 - 114 -01 Revision 01
Page 6 HLU- 431 List 1D
HDSL Line Voltage Option
The symmetry of the HDSL line powering voltage can be set by the S2
switch, located on the printed circuit board.
The factory default setting is Unipolar (-). It sets the HDSL line voltage to
0 V on loop 2 and to either -140 V (for non-doubler applications) or -200 V
(for doubler applications) on loop 1.
The Bipolar selection sets the HDSL line voltage to +70 V on loop 2 and
-70 V on loop 1, for non-doubler applications. Doubler applications will have
+100 V on loop 2 and -100 V on loop 1. The symmetry of the HDSL line
powering voltage can be set by the S2 switch, located on the printed circuit
board.
Provisioning
The HLU- 431 List 1D contains a non-volatile RAM (NVRAM) which stores
the system option settings. The options are set via buttons on the front panel,
or through the RS-232 interface. They are retained if shelf power is lost or if
the HLU-
431 List 1D is unplugged. The System Options table on page 8 lists
the system options for the HLU- 431 List 1D .
Using the SEL and Mode Front Panel Buttons
To provision the HLU- 431 List 1D through the SEL and MODE front-panel
buttons:
1 Press the MODE button for approximately one second. The message
displayed on the front panel alternates between the first system parameter
and its current setting.
2
Press the SEL button to step the display through all possible settings (one
at a time) of the parameter being displayed.
3
Press the MODE button to select the desired parameter and move to the
next parameter. After you have configured the last parameter, the
display prompts you to confirm the settings.
4
Do one of the following:
• Press the SEL button to install the settings.
• Press the MODE button to bypass the settings.
If neither button is pressed in 30 seconds, the settings are bypassed.