User's Manual

MODEL 2130 MARKER BEACON
1-2 Rev. A April, 2005
This document contains proprietary information and such information may not be disclosed to others for any
purposes without written permission from SELEX Sistemi Integrati Inc.
When used for en route applications, the Marker Beacon is configured as a fan marker. It can be used with other
Navigational Aid equipment and its use depends upon instrument flight procedural applications.
For ILS operation, an outer marker is typically located 4 nautical miles from the runway threshold; this location normally
coincides with the point on the ILS approach at which the glide slope altitude equals the intercept altitude. A middle
marker is typically located 3,500 feet from the runway threshold; this location normally coincides with the point on the
glide path at which the Decision Height (DH) is located for Category I operations 200 feet above the touchdown zone
elevation. The inner marker is only installed for Category II and III ILS approaches, and is located approximately 1000 feet
from the runway approach threshold, coinciding with the nominal Category II decision height of 100 feet.
The inner, middle and outer marker antennas are single five element Yagis.
The Marker Beacon (Figure 1-2) is of modular design and completely solid-state. Both single equipment and dual
equipment transmitters are available. Battery backup (Figure 1-6) is optional and provides power in case of primary AC
power failure. Operating control of the Marker Beacon system is by a Portable Maintenance Data Terminal (PMDT) The
PMDT is an IBM compatible personal computer running SELEX SISTEMI INTEGRATI INC. proprietary application
software. The two antenna configurations (pole and tower) are shown in Figure 1-4.
Microprocessor-controlled monitoring and built-in test equipment are an integral part of the equipment. This allows
continuous monitoring of all required parameters as well as the testing, control, and display of voltages, currents, and
frequencies.
The Marker Beacon can be remotely monitored through:
a. Dedicated telephone lines to the Model 2238 Remote Status Control Unit.
b. Optional radio link operating at either 900 MHz or 2.4 GHz.
c. Remote Maintenance Monitoring (RMM) - Switched telephone lines and modem integrated within the 2130 Marker
Beacon allow for interface to remote monitoring points using the PMDT software.
1.2.1 Monitoring Systems
A high integrity integral monitoring system incorporated in the Marker Beacon system to provide fault detection by
monitoring the transmitted signals and initiating automatic station transfer to a standby transmitter or shutdown in the
event of an out-of-tolerance condition.
Dual, parallel monitoring channels are included for measurement of important signal parameters for the On-the-Air
Transmitter and Standby Transmitter.
Independently adjustable pre-alarm (maintenance alert) indications are included for all executive monitoring parameters.
All executive and maintenance alarm indications are provided both locally at the station and remotely through the Remote
Maintenance Monitoring (RMM) system.
Integrity of the monitors is assured by certification testing using a built-in Test Generator.
Failsafe design of the monitors ensures the removal of Navigation and Identification signals and the transmission of a
warning signal to the remote control and monitoring points in the event of a failure in the monitoring system itself.
Failsafe testing of the monitors and control circuits has been performed to verify that any single failure of a component,
open or short in the monitor(s) or control circuit will either result directly in an alarm condition, or will not alter any alarm
threshold level to allow an out-of-tolerance condition to occur without detection.
The monitoring system includes a bypass capability to disable the automatic station control action during adjustment and
maintenance. Front panel amber "bypass" and "alarm" lights are illuminated any time the integral or standby transmitter