8
MDS 4790M (MPT 1411) I/O Guide
MDS 05-3628A01, Rev. B
RSSI
—Received signal strength indication. Expressed in dBm.
RTU
—Remote Terminal Unit. A data collection device installed at a remote
radio site. An internal RTU
simulator
is provided with the radio to isolate
faults to either the external RTU or the radio. For more information see “RTU
[ON/OFF/0-80]” on page 39
SNR
—Signal-to-noise ratio. Expressed in decibels (dB).
SWR
—Standing Wave Ratio. A parameter related to the ratio between
forward transmitter power and the reflected power from the antenna system.
As a general guideline, reflected power should not exceed 10% of the forward
power (
≈
2:1 SWR).
3.0
INSTALLATION PLANNING
The installation of the radio is not difficult, but it does require some planning
to ensure reliability and efficiency. This section provides tips for selecting an
appropriate site, choosing antennas and feedlines, and minimizing the chance
of interference. This material should be reviewed before beginning equipment
installation.
3.1 General Requirements
There are three main requirements for installing the radio—adequate and
stable primary power, a good antenna system, and the correct interface
between the radio and the data device. Figure 5 shows a typical station
arrangement.
Invisible place holder
Figure 5. Typical Station Arrangement
Site Selection
For a successful installation, careful thought must be given to selecting the site
for the master station and the remote radios. Suitable sites should offer:
TO INPUT
POWER SOURCE
LOW LOSS
COAXIAL CABLE
OMNIDIRECTIONAL
ANTENNA
HOST COMPUTER
DIAGNOSTICS
COMPUTER
