3
Section 61246001L2-5, Issue 2
61246001L2-5B
Switch Options
One six-position rotary switch (SW7) and a five-
position dipswitch pack (SW6) accessible from the
faceplate of the unit are used to configure the mode of
operation. In addition, a single position dipswitch
pack (SW2), is mounted on the board to adjust span
powering voltage. Figures 1 and 2 show the location
of these switches.
A definition of each switch is shown in Tables 2 and
3. Configuration may be performed by manually
selecting each option switch, or alternatively, may be
performed using the RS-232 craft access port. Manual
configuration can be performed after installing the
unit into the shelf.
NOTE:
When the unit is powered up, changing a
single faceplate switch only affects that single
parameter. When the unit is powered down,
changing a single faceplate switch causes a
global reset to revert back to all faceplate
switch settings. This includes the removal of
DS0 Blocking parameters.
NOTE:
Craft interface allows configuration of DS0
Blocking and additional loopback timeout
settings.
Faceplate Indicators
The HTU-C M has five faceplate LEDs which indicate
operational status. Table 4 defines these LEDs.
Powering Options
Using SW2 (see Figure 2), the HTU-C M can be
optioned for two different span powering modes. By
selecting “LV” span powering mode, the HTU-C M
will provide span powering at less than -140 VDC.
This mode allows span powering of circuits without
HREs or with one HRE.
By selecting “HV” span powering mode, the
HTU-C M will provide span powering at -190 VDC.
This mode allows span powering of circuits with two
HREs and an HTU-R.
3. CONNECTIONS
The 220/E220 HTU-C M occupies one card slot in a
220 Office Repeater Bay. Power and alarm signals are
provided to the card through the backplane of the
shelf. DSX-1 and HDSL loop signals are connected to
the wire-wrap pins or mass termination shelf
connectors corresponding to the slot the unit occupies.
See Figure 3 for HTU-C M edge connection wiring.
The HTU-C M is capable of span powering the
HTU-R by applying simplex current to the local loop.
10 to 125
m
A of current is coupled onto the HDSL
span to power the HTU-R and HRE(s) when
deployed. The span powering voltage is applied with
Loop 1 providing the negative voltage and Loop 2 the
return (see Figure 4).
Figure 2. HTU-C M Switch Arrangement
ON
SW2
HV
LV
