1、二次雷達（SSR）outline2IntroductionComponents Antenna(2)ATC coax switch (2)ATC/TCAS control panelATC transponder (2).InterfaceSelf testIntroduction3The air traffic control (ATC) ground stations interrogate the airborne ATC system. The ATC transponder replies to the interrogations in the form of coded info

2、rmation that the ground station uses.The ATC transponder also replies to mode S interrogations from the traffic alert and collision avoidance systems (TCAS) of other airplanes or ground stations.When a ground station or a TCAS computer from another airplane interrogates the ATC system, the transpond

3、er transmits a pulse-coded reply signal. The reply signal identifies and shows the altitude of the airplane.Introduction4Introduction5These are the components of the ATC system:Top antennaBottom antennaATC coax switch (2)ATC/TCAS control panelATC transponder (2).Introduction6COMPONENT LOCATIONFlight

4、 CompartmentThe ATC/TCAS control panel is on the P8 aft electronics panel.Electronic Equipment CompartmentThese are the ATC transponder system components in the electronic equipment compartment:ATC transponder 1ATC transponder 2Program switch module (2)Top ATC coax switchBottom ATC coax switch.ATC A

5、ntenna LocationThe ATC antennas are on the forward fuselage near the centerline. The top ATC antenna is at STA 430.25. The bottom ATC antenna is at STA 355.7Introduction8Components - Antenna9Purpose: The ATC L-band blade antenna receives 1030 MHZ interrogation signals from ATC ground stations and ot

6、her airplanes that have TCAS. The ATC transponder transmits the reply signals through the L-band antenna.Physical Description: The coaxial cable connector connects to the antenna. The antenna has an O-ring moisture seal and attaches to the airplane by four screws. The ATC and DME antennas are the sa

7、me and are interchangeable.The ATC coax switches get power through the ATC ANT SWITCH circuit breaker. When you select ATC transponder 1 on the ATC/TCAS control panel, the ATC coax switches do not energize and the antennas connect to ATC transponder 1. When you select ATC transponder 2, the ATC/TCAS

8、 control panel sends a discrete ground to the ATC coax switches. This energizes the coax switches and connects the top and bottom antennas to ATC transponder 2.Components - Antenna10ATC coax switchThe ATC coax switches connect the active ATC transponder to the top and bottom ATC antennas.These are t

9、he electrical connector inputs:ATC antenna switch circuit breakerATC/TCAS control panel.The ATC coax switches supply an RF interface for the ATC system interrogation and reply signals. These are the connectors:ATC transponder 1 connectorATC antenna connectorATC transponder 2 connector.11ATC/TCAS CON

10、TROL PANELThe dual ATC/TCAS control panel controls the ATC transponder and the TCAS computer. These are the ATC controls and displays on the ATC/TCAS control panel:Transponder select switchActive system displayTransponder code selectors Codes are from 0000 to 7777, with 4096 different selections.Fou

11、r digit identification code (NO 7500, 7600 OR 7700)Transponder mode selectorIDENT switchAltitude source switchFail light12ATC/TCAS CONTROL PANEL13ATC/TCAS CONTROL PANEL14ATC/TCAS CONTROL PANEL15ATC/TCAS CONTROL PANELThe transponder select switch is a two-position switch used to select ATC transponde

12、r 1 or ATC transponder 2 as the active transponder.The flight crew uses the code selectors to set the four digits of the identification code. The four digits show on the liquid crystal display (LCD). Codes are from 0000 to 7777, with 4096 different selections.16ATC/TCAS CONTROL PANELTransponder Mode

13、 SelectorTEST - Starts an ATC transponder functional test.STBY (standby) - A ground discrete goes to both transponders. This ground discrete prevents operation of the transponder, but does not prevent built-in-test-equipment (BITE) functions.ALT RPTG OFF (altitude reporting off) - The reply does not

14、 contain an altitude report.XPNDR (transponder) - The active transponder responds to ATC interrogations. Mode C and Mode S altitude replies contain altitude information.17ATC/TCAS CONTROL PANEL18IDENT Switch. When the ATC controller requests the airplane identifier, the flight crew pushes the moment

15、ary IDENT switch. The transponder adds a special position identification (SPI) pulse to the interrogation reply for the next 18 seconds.Altitude Source Switch. Use the two-position switch to set the source of altitude data for the ATC transponder. XPNDR FAIL Light. The XPNDR FAIL light comes on for

16、these conditions: Transponder failure; Antenna failure; Control data failure; Altitude input failure.ATC TRANSPONDERThe ATC ground station interrogates the ATC transponder with a pulse-coded signal at a frequency of 1030 MHz. The transponder responds with pulse-coded signals at a frequency of 1090 M

17、Hz.The transponder responds to air traffic control radar beacon system (ATCRBS) mode A and mode C interrogations. The transponder also responds to air traffic control and the TCAS computer with the mode select (mode S) format.19ATC TRANSPONDER20ATC TRANSPONDER21The light emitting diode (LED) status

18、indicators on the front panel show for these conditions:TPR LED (green), if there are no LRU failuresTPR LED (red), if there is an LRU failureALT, if the altitude input from the ADIRU failsDATA IN, if the control panel input failsTOP, if the top antenna failsBOT, if bottom antenna failsTCAS, if the

19、interface with TCAS failsMAINTENANCE, not usedRESERVED(2), not used.InterfaceANTENNA INTERFACE(天線接口)POWER, IDENTITY, CONTROL, AND AIR DATA INTERFACES(電源、識別、控制和大氣數(shù)據(jù)接口) MMR AND MODE CONTROL PANEL INTERFACES(多模式接收機和模式控制面板接口)MAINTENANCE INTERFACE(維護接口)TCAS INTERFACE AND PROGRAM PINS(TCAS 接口和程序銷釘)SUPPRES

20、SION INTERFACE(抑制接口)22Self test23Push the TEST switch on the front of the transponder or select TEST on the ATC/TCAS control panel to start a self-test of the ATC system. During the test, the transponder BITE circuits do these functions:Normal operation testMemory testsSimulated interrogation test o

21、f the receiver circuitsAntenna impedance testTCAS interface testValid control and altitude inputs monitor.Self test24Self test25Test From the Front Panel. Push and hold the test switch. All front panel light emitting diode (LED) status indicators come on for three seconds. Then all the LEDs go off for two seconds. Continue to hold the test switch to see the applicable LE