Connections; Figure 2. H2Tu-C Edge Connector Wiring; Figure 3. H2Tu-C Span Powering Diagram - ADTRAN DDM+ H2TU-C Installation And Maintenance Manual

Powering Modes
The H2TU-C will automatically provide span
powering voltage. No voltage settings are required,
regardless of the presence of a H2R.
Shelf Population
(based on power requirements)
Typically, the AT&T DDM+ shelf is fused at 10 amps
per side (one half of the shelf). A worksheet for
calculating the maximum number of DDM+ H2TU-Cs
allowed in the AT&T DDM+ Shelf is located in
Appendix B of this practice.
Several H2TU-C s can be mixed with other DDM+
standard plug-ins, providing that the total current draw
per shelf side is less than or equal to 5A. Refer to the
original equipment manufacturer's specifications for
more detail on specific power requirements of these
units.

3. CONNECTIONS

The DDM+ H2TU-C occupies one card slot in an
AT&T DDM+ shelf. Power and alarm signals are
provided to the card through the backplane of the
shelf. DSX-1 and HDSL2 loop signals are connected
to the wire-wrap pins or mass termination shelf
connectors corresponding to the slot the unit occupies.
See Figure 2 for H2TU-C edge connection wiring.
The H2TU-C is capable of span powering the
H2TU-R by applying simplex current to the local
loop. From 10 to 150 mA of current is coupled onto
the HDSL2 span to power the H2TU-R when
deployed (see Figure 3).
H2TU-C Alarm Outputs
Pin 117 of the H2TU-C edge connector interface
provides a fuse alarm signal that connects -48 VDC to
this pin in the presence of a blown fuse or loss of
signal. This indicates the card has malfunctioned and
should be replaced.
Alarm processing is actually performed by the DDM+
Alarm Module. Refer to the DDM+ Alarm Module
documentation for further information.
Alarm conditions are not reported at the DDM+
H2TU-C until the HDSL2 circuit is terminated, by
connecting an H2TU-R. This allows circuit pack
pre-provisioning. Once the HT2U-C is terminated
with an H2TU-R, the unit will go into an in-service
state.
61222003L1-5A

Figure 2. H2TU-C Edge Connector Wiring

HDSL2

Figure 3. H2TU-C Span Powering Diagram

61222003L1-5, Issue 1
100
HDSL2 Tip
101
HDSL2 Ring
102
103
104
105
106
107
108
DSX-1 RX Tip
109
DSX-1 RX Ring
110
111
112
113
DSX-1 TX Tip
114
DSX-1 TX Ring
115
116
Alarm (to Alarm Module)
117
-48V Return
118
Frame Ground
119
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
-48V
217
-48 V Return
218
-48 V Return
219
SPAN CURRENT
SPAN POWER
TIP (+)
(101)
190V
RING (-) (102)
3