User Manual

ADCP-75-159 • Issue 1 • August 2003 • Section 2: Description
Page 2-21
© 2003, ADC Telecommunications, Inc.
6.3 Fault Detection and Alarm Reporting
The LPA in conjunction with the STM detects and reports various faults including power
amplifier fault, output power fault, temperature fault, and fan fault. A single Light Emitting
Diode (LED) indicator, located on the front panel of the LPA, turns from green to red or yellow
if an LPA fault is detected. The status of the LPA, the alarm state (major or minor), and other
information is summarized and reported (by the STM) over the optical fiber to the HU and also
to the service interface. This information may be accessed remotely through the NOC/NEM
interface or locally through the EMS software GUI.
6.4 Powering
The LPA is powered by various DC voltages which are supplied by the STM over the electrical
interface provided by the D-sub connectors and wiring harness mounted within the RU outdoor
cabinet or RU indoor mounting shelf.
6.5 Cooling
Continuous air-flow for cooling is provided by a fan mounted at the front of the LPA housing.
Cool air is pulled into the module from the front and heated air is exhausted out the back. An
alarm is provided that indicates if a high temperature condition (>50º C/122º F) occurs or if a
fan failure occurs. The fan may be field replaced if it fails.
6.6 User Interface
The LPA user interface consists of an LED indicator and a switch that are mounted on the LPA
front panel. The LPA user interface points are described in Table 2-5 and indicated in
Figure 2-10.
Table 2-5. Linear Power Amplifier User Interface
REF
NO
USER INTERFACE
DESIGNATION
DEVICE
FUNCTIONAL
DESCRIPTION
1 STATUS LED indicator
(green, yellow, and
red)
Indicates the operational state of the LPA and
whether or not there are any faults.
2MUTE
NORM
RESET
3-position switch
with one momentary
contact position
Placing the switch in the MUTE position puts the
LPA in the shutdown state with RF output disabled.
With the switch in MUTE, the STM can not control
the LPA output power. Placing the switch in the
NORM position puts the LPA in the normal state
and allows the STM to enable and disable the RF
output. Momentarily placing the switch in the
RESET position clears all alarms and restarts the
LPA.
Note: A more detailed description of the STATUS LED is provided in Section 5.