User Manual

ADCP-75-159 • Issue 1 • August 2003 • Section 2: Description

Page 2-4

Figure 2-1. Host Unit

2.3 Fault Detection and Alarm Reporting

The HU detects and reports various faults including host unit fault, optical fault, power fault,

temperature fault, and RF fault. Various front panel Light Emitting Diode (LED) indicators turn

from green to red or yellow if a fault is detected. A set of alarm contacts (normally open and

normally closed) are provided for reporting an alarm to an external alarm system when a fault is

detected. Both major alarm (system operation seriously affected) and minor alarm (system

operation not affected or only slightly degraded) contacts are provided.

The status of the HU, the alarm state (major or minor), and other alarm information is

summarized and reported over the service interface, the CAN interface, and also over the optical

interface to the RU. In addition, the state of the RU is received over the optical fiber and reported

over the service interface and the CAN interface. This detailed information may be accessed

remotely through the NOC/NEM interface or locally through the EMS software GUI.

2.4 RF Signal Connections

The RF signal connections between the HU and the EBTS are supported through two N-type

female connectors. One connector is used for the forward path RF signal. The other connector is

used for the reverse path RF signal. The current 20 Watt system does not support a diversity

reverse path. In installations where multiple EBTS’s will be connected to a single HU, it will

usually be necessary to install a Primary Interface Panel and an Expansion Panel (accessory

items) to support the interface between the HU and the EBTS. The HU should be as close as

possible to the EBTS to minimize cable losses.

2.5 RF Signal Level Adjustments

The HU is equipped with several attenuators for adjusting the signal levels of the forward and

reverse path RF signals. The attenuators provide an attenuation adjustment range of 0 to 20 dB

and can be set in 1 dB increments. The attenuators are software controlled and are adjusted

through the NOC/NEM interface or the EMS software GUI.

17.1 INCHES

(433 mm)

3.5 INCHES

(88 mm)

12.2 INCHES

(311 mm)

FRONT PANEL

MOUNTING

BRACKET

(BOTH SIDES)

17857-A