User's Manual

ADCP-75-132 • Issue 2C • August 2006
Page 6
© 2006, ADC Telecommunications, Inc.
2.1.7 Cooling
Continuous air-flow for cooling is provided by dual fans mounted on the right side of the
housing. A minimum of 3 inches (76 mm) of clearance space must be provided on both the
left and right sides of the DHU for air intake and exhaust. An alarm is provided that indicates
if a high temperature condition (>50º C/122º F) occurs. The fans may be field-replaced if
either fan fails.
2.1.8 User Interface
The DHU user interface consists of the various connectors, switches, terminals, and LEDs that
are provided on the DHU front panel. The DHU user interface points are described in Table 1
and indicated in Figure 3.
Table 1. Digital Host Unit User Interface
REF
No.
USER INTERFACE
DESIGNATION DEVICE
FUNCTIONAL
DESCRIPTION
1
Ground stud Used for connecting a grounding cable to
the DHU chassis.
2 POWER 3-wire AC power
cord connector
Used for connecting the AC power cord.
3 I/O I/O rocker switch/
circuit breaker
Provides AC power On/Off control and
AC power over current protection.
4 OK/NOK (Ports 1–6) Multi-colored LED
(Red/Green/Yellow)
Indicates if the DRU or remote DEU connected
to the optical port is normal or faulty or if the
reverse path optical input from the DRU or
remote DEU is normal or lost. (see Note)
5 ON/OFF (Ports 1–6) I/O rocker switch Enables or disables corresponding
electrical and optical ports.
6 DC PWR (Ports 1–6) RJ-45 jack (female) Used for connecting a DRU cat 3 or 5 power
cable to the designated DC power jack.
7 FIBER (Ports 1–6) LC-type optical
transceiver
Used for connecting each DEU or DRU
forward path and reverse path optical fibers
to the designated optical port.
8 UNIT Multi-colored LED
(Red/Green/Yellow)
Indicates if the DHU is normal or faulty.
(see Note)
9 OVERDRIVE Multi-colored LED
(Red/Green/Yellow)
Indicates when the forward path RF input
power is overdriving the DHU digitizing
circuitry. (see Note)
10 MAJOR MINOR Screw-type terminal
connector
(14–26 AWG)
Used for connecting an external alarm system
to the DHU. Includes normally open (NO),
normally closed (NC), and common (COM)
wiring connections.
11 RF IN N-type female RF
coaxial connector
Used for connecting the forward path RF
coaxial cable to the DHU.
12 RF OUT N-type female RF
coaxial connector
Used for connecting the reverse path RF
coaxial cable to the DHU.
Note: A more detailed description of LED operation is provided in Section 5.