User's Manual

ADCP-75-132 • Issue 2C • August 2006

Page 8

2.2.1 Primary Components

The DRU consists of an electronic circuit board assembly that is mounted within a powder-

coated sheet metal enclosure. The metal enclosure provides a mounting point for the

electronic assembly, serves as a heat sink, and controls RF emissions. Except for the optical

transceiver, the DRU components are not field replaceable. The DRU is designed for use

within a non-condensing indoor environment such as inside a building. All controls,

connectors, and indicators (except the SMA antenna connector) are mounted on the DRU front

panel for convenient access.

2.2.2 Mounting

The DRU is equipped with four integral mounting feet that allow it to be mounted on any flat

horizontal or vertical surface. A typical location for mounting the DRU would be on a ceiling

or a wall. Slots are provided in the mounting feet for securing the DRU to the mounting

surface.

2.2.3 Fault Detection

The DRU detects 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 reverse path optical fiber. A

corresponding port LED at the DHU or DEU turns from green to red when the DRU reports a

fault.

2.2.4 Antenna Connection

The RF signal interface between the DRU and the cellular users is provided through an

external antenna. An SMA connector is provided for connecting the DRU to the antenna. 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 but must comply with equipment authorization for RF exposure compliance.

2.2.5 Optical Port

The DRU uses a small form factor LC-type optical transceiver for connecting the optical

fibers. Each transceiver is color-coded to identify whether it supports single-mode (blue) or

multi-mode (black/beige) fiber. Depending on the application requirements, the optical port

may be connected to either a DHU or a DEU. The modular optical transceiver is an accessory

item and is field replaceable.

2.2.6 Powering

The DRU is equipped with a female RJ-45 jack that provides a connection point for the 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