Alarm Connections; Figure 4. Ddm+ Htu-C Span Powering Diagram - ADTRAN HDSL DDM+ HTU-C Installation And Maintenance Practice

The DDM+ HTU-C is capable of span powering the HTU-R by applying simplex current to the
local loop. From 30 mA to 155 mA of current is coupled onto the HDSL span to power the
HTU-R and HRE when deployed. The span powering voltage can be configured to be –190
volts with Loop 1 providing the negative voltage and Loop 2 the return

Alarm Connections

The following alarm signal is connected to the DDM+ Alarm Module:
• Pin
• Label
• Function
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+ HTU-C until the HDSL circuit is terminated by
connecting an HTU-R. This allows circuit pack pre-provisioning. Once the DDM+ HTU-C is
terminated with an HTU-R, the unit will go into an in-service state.
61247003L6-5A
2B1Q SPAN POWER
HDSL REGULATOR

Figure 4. DDM+ HTU-C Span Powering Diagram

117
LOS and Fuse Alarm
Loss of signal and fuse alarm of –48 V supply
(Figure
T (101)
LOOP 1
R (102)
SPAN CURRENT
T1 (105)
LOOP 2
R1 (106)
Connections
4).
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