User's Manual

ADCP-75-187 • Issue 1 • September 2005 • Section 2: DESCRIPTION

Page 2-3

Figure 2-1. Host Unit

2.3 Fault Detection and Alarm Reporting

The HU detects and reports various internal and external 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.

Fault and alarm information may also be accessed locally through the EMS software GUI or

remotely through the NOC/NEM interface or SNMP interface. An alarm history file is

maintained by the EMS software so that a record is kept of all alarms as they occur. This is

useful when an alarm is reported and cleared before the reason for the alarm can be determined.

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 the optical interface

to the RU. In addition, the status of the RU is transmitted to the HU over the optical interface

and reported over the service interface and the CAN interface.

2.4 RF Signal Connections

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

female connectors. Two connectors are used for the forward path RF signals. The other two

connectors are used for the reverse path RF signals. In most installations, it is usually necessary

to install external attenuators to support the RF interface between the HU and the EBTS. The

HU should be as close as possible to the EBTS to minimize coaxial cable losses.

17.1 INCHES

(433 mm)

3.5 INCHES

(88 mm)

12.2 INCHES

(311 mm)

FRONT PANEL

MOUNTING

BRACKET

(BOTH SIDES)

20020-A