ADC Digivance, Инструкция по установке и эксплуатации

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ADCP-75-110
•
Issue 2B
•
July 2001
Page 8
©
2001, ADC Telecommunications, Inc.
1.3.3 Fault Detection
The
DRU is designed to detect internal circuitry faults or loss of system inputs. A front panel
LED
indicator turns from green to red when a fault condition is detected or when the optical
input
is lost. The DRU sends the fault information to the DHU or DEU over the fiber optic
link.
A corresponding port LED at the DHU or DEU turns from green to red when the DRU
reports
a fault.
1.3.4 RF Signal Interface
The
RF signal interface between the DRU and the cellular users is provided through an
external
antenna connected to a female SMA connector. The antenna must be ordered
separately.
Several types of antennas with various RF propagations are available. Non-ADC
antennas
may also be used with the DRU to meet various application requirements.
1.3.5 Optical Port
The
DRU is equipped with a small form factor LC type optical transceiver that provides a
point
for connecting the optical link cables. Depending on the application requirements, the
optical
port may be connected to either a DHU or a DEU.
1.3.6 Powering
The
DRU is equipped with a female RJ-45 jack that provides a point for connecting a DC
power
cable. The DRU is powered by 34–48 Vdc power which is supplied through the RJ-45
connector.
Power to the DRU may be supplied by the DHU, DEU, or by a 120 Vac to 48 Vdc
power
converter (available separately as an accessory item) plugged into a properly grounded
120
Vac outlet. The ac/dc converter is a UL Listed stand alone Limited Power Supply (LPS)
unit
with a rated output of 48 Vdc at 1.2 Amps. When powered by the DHU or DEU, a
category
3 or 5 twisted-pair cable terminated with RJ-45 connectors is required.
1.3.7 Cooling
The
DRU is cooled by natural convection air flow. The DRU mounting feet are designed to provide
clearance
under the unit so that air can enter the DRU enclosure from the bottom and exit through
the
top. A minimum clearance of 3 inches (76 mm) must be provided on all sides of the DRU
(except
the bottom) to ensure there is adequate air circulation for cooling. In addition, at least one
surface
of the DRU installation area must be open to the interior of the building.
1.3.8 User Interface
The
DRU user interface consists of the connectors and the LED that are provided on the DRU
front
and rear panels. The DRU user interface points are indicated in Figure 5 and described in
Table
2.