User Manual

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

Page 2-17

female connector located on the rear side of the STM. A corresponding D-sub male connector

mounted at the rear of the RU cabinet or RU mounting shelf mates with the STM connector.

Captive screws are provided for securing the STM in the installed position.

5.3 Fault Detection and Alarm Reporting

The STM detects and reports various faults including remote unit fault, optical fault, power

fault, temperature fault, power amplifier fault, and external (door open) fault. Various front

panel Light Emitting Diode (LED) indicators turn from green to red or yellow if a fault is

detected. The status of the STM, the alarm state (major or minor), and other alarm information

is summarized and reported over the optical interface to the HU and also over the service

interface. In addition, the alarm state of the HU is received over the

optical interface and

reported to the service interface. This information may be accessed remotely through the NOC/

NEM interface or locally through the EMS software GUI.

5.4 Antenna Cable Connection

The antenna cable connections between the STM and the antenna are supported through one N-

type female connector which carries both the forward and reverse path RF signals. When

installed in the RU outdoor cabinet, the STM does not connect directly to the antenna but

instead connects to a lightning protector that is mounted on the bottom of the cabinet (see

Section 3.6). A coaxial jumper cable is provided (included with the enclosure) for connecting

the STM to the lightning protector.

5.5 RF Signal Level Adjustment

The STM is equipped with a digital attenuator for adjusting the signal level of the forward path

RF output signal. The remote forward path attenuator adjusts the level of the output RF signal

at the RU antenna port and will add from 0 to 20 dB of attenuation to the output signal level.

The attenuator can be set in 1 dB increments. The attenuator is software controlled and is

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

5.6 Optical Connection

Fiber optic connections between the STM and the HU are supported through two SC-type

optical connector ports. One port is used for connecting the forward path optical signal and the

other port is used for connecting the primary reverse path optical signal.

5.7 Service Interface Connection

The service interface connection between the STM and a local laptop computer loaded with the

EMS software is supported by a single DB-9 female connector. The service interface connector

provides an RS-232 DTE interface. The STM service interface connector supports local

communications with both the STM and the corresponding HU.