User's Manual

SYSTEM DESCRIPTION AND INSTALLATION MANUAL
TCAS 3000 Traffic Alert and Collision Avoidance System
34−43−23
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Page 1−32
15 Dec 2005
(1) Functional Description and Operation
Communication with Mode S transponders is accomplished through an ARINC 429
bus as defined in ARINC Characteristic 718−A. Control panel functions include 4096
ident code selection and display, altitude source and reporting inhibit selection,
selection between two onboard transponders, TCAS TA or TA/RA advisory selection,
range selection (in nautical miles) and a system functional test selection. A
description of the front panel annunciator and switch functions follows:
(a) Transponder Code Display
The control panel has a single LCD display that is common to both modules
within the unit. The display shows the ATC code selected by the user and
consequently transmitted to the transponders. Input to the display is controlled
by the system select switch (XPNDR 1−2).
In addition, certain fault indications are also indicated on the display. After a
functional test has been initiated, PASS shows on the display after a successful
test, or it shows FAIL if a high level failure is detected under normal operating
conditions. It also shows which transponder is active by displaying ATC 1 or 2.
(b) ATC Code Selection
The ATC four digit code is selected with two dual concentric sets of knobs. Each
knob is dedicated to a single liquid crystal display (LCD) digit on the LCD code
display. The two smaller knobs control the inner digits of the LCD (tens and
hundreds) while the two larger knobs control the outer most digits (units and
thousands).
(c) XPNDR 1−2 Switch
The XPNDR switch is a two position switch that allows the selection of one
Mode−S module in the control panel, and the activation of its associated
transponder (System 1 or System 2).
(d) Mode Control Selector Switch
The rotary switch labeled STBY−ALT RPTG OFF−XPNDR−TA ONLY−TA/RA
allows the operator to activate the TCAS system by selecting TA, or traffic and
resolution advisory (TA/RA). When STBY is selected, both transponders are
selected inactive or in standby mode. Altitude reporting off (ALT RPTG OFF)
selection disables the altitude data sources interrupting transmission of aircraft
altitude and location information to ground controllers.
(e) ABV/N/BLW Switch
The ABV/N/BLW switch selects an altitude range (from aircraft) for traffic display
on the TCAS displays. Range limits are 9900 feet above and 2700 feet below
the aircraft when in ABV mode and 2700 feet above and 9900 below the aircraft
when in BLW mode. When the normal (N) position is selected, the display range
is 2700 feet above and below the aircraft.