User's Manual Part 1

ADCP-75-187 • Preliminary Issue 1B • November 2005 • Section 2: DESCRIPTION
Page 2-3
© 2005, ADC Telecommunications, Inc.
Figure 2-1. Rear and Front Access Host Units
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.
17.1 INCHES
(433 mm)
3.5 INCHES
(88 mm)
12.2 INCHES
(311 mm)
FRONT PANEL
MOUNTING
BRACKET
(BOTH SIDES)
REAR ACCESS HOST UNIT
FRONT ACCESS HOST UNIT
20666-A
17.2 INCHES
(437 mm)
3.5 INCHES
(89 mm)
11.4 INCHES
(290 mm)
15.3 INCHES
(389 mm)
FRONT PANEL
CABLE MANAGEMENT
TRAY
MOUNTING
BRACKET
(BOTH SIDES)