4
Section 61245001L7-5, Issue 1
61245.001L7-5A
Figure 2. HTU-C Edge Connector Wiring
3.
CONNECTIONS
The E220/220 Low Voltage HTU-C 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
2 for HTU-C edge connection wiring.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Local RS485 +
-48 RET
Card Sense
Slot ID 1
Slot ID 2
Slot ID 3
Slot ID 4
Loop 1 HDSL Tip (Wire-Wrap)
Loop 1 HDSL Ring (Wire-Wrap)
Loop 2 HDSL Ring (Wire-Wrap)
Loop 2 HDSL Tip (Wire-Wrap)
-48V(1)
DSX-1 Rx Tip (Wire-Wrap)
DSX-1 Rx Ring (Wire-Wrap)
-48 RET
DSX-1 Tx Tip (Wire-Wrap)
DSX-1 Tx Ring (Wire-Wrap)
Local RS485 -
Active only
in ADTRAN
E220 Shelf
Fuse Alarm
Input to HTU-C
Output from HTU-C
Input to HTU-C
Output from HTU-C
The HTU-C is capable of span powering the HTU-R by
applying simplex current to the local loop. 30 to 155
mA
of current is coupled onto the HDSL span to power the
HTU-R and HRE when deployed. The span powering
voltage is less than –140 volts with Loop 1 providing the
negative voltage and Loop 2 the return (see Figure 3).
2B1Q
HDSL
SPAN POWER
REGULATOR
SPAN CURRENT
T (26)
R (27)
T1 (34)
R1 (35)
LOOP 1
LOOP 2
Figure 3. HTU-C Span Powering Diagram
HTU-C Alarm Outputs
Pin 32 of the HTU-C edge connector interface provides
a fuse alarm signal that connects –48 VDC to this pin in
the presence of a blown fuse. This indicates the card has
malfunctioned and should be replaced.
HFAC Alarm Outputs
If the HTU-C is operating in an ADTRAN E220 or E220
RP Shelf with an HFAC (P/N 1244051LX or equivalent),
the HTU-C provides information to the HFAC which is
used to generate alarms. The HFAC alarm outputs are
separate from the HTU-C alarm pin mentioned above.
For more information on the HFAC controlled alarms,
see the HFAC Installation and Maintenance practice,
section 61244051LX-5.
