ARINC 718-4:1989

1.0 INTRODUCTION AND DESCRIPTION
1.1 Purpose of This Characteristic
1.2 ATCRBS System Description
1.3 Mode S System Description
1.4 ATCRBS/Mode S Compatibility
1.5 Transponder Functions
1.6 Unit Description
     1.6.1 Transponder Unit
     1.6.2 Transponder Control
     1.6.3 Antenna
     1.6.4 Altitude Reporting Data
     1.6.5 Mode S Data Link
1.7 Interchangeability
     1.7.1 General
     1.7.2 Interchangeability Desired For The ARINC 718
     Transponder System
     1.7.3 "Generation Interchangeability" Considerations
1.8 Regulatory Approval
2.0 INTERCHANGEABILITY STANDARDS
2.1 Introduction
2.2 Form Factor, Connectors and Index Pin Coding
     2.2.1 Transponder Unit
     2.2.2 "Standard Control Panel"
     2.2.3 Antenna
2.3 Interwiring
2.4 Power circuitry
     2.4.1 Primary Power Input
     2.4.2 Power Control Circuitry
     2.4.3 The Common Ground
     2.4.4 The AC Common Cold
2.5 Standard SM and ELM Interface
2.6 Environmental Conditions
2.7 Cooling
2.8 Grounding and Bonding
3.0 SYSTEM CHARACTERISTICS
3.1 Purpose of This Chapter
3.2 ATCRBS/Mode S Compatibility
3.3 Interrogation Signal Characteristics
     3.3.1 ATCRBS Interrogations
     3.3.2 Mode S Sensor Interrogation
3.4 Reply Transmission Characteristics (Signals-in-
     Space)
     3.4.1 ATCRBS Reply Transmissions
     3.4.2 Mode S Reply Transmissions
     3.4.3 Reply Carrier Frequency
3.5 ATC System Use of Mode S
3.6 Sources of Reply Code Data
4.0 TRANSPONDER UNIT DESCRIPTION
4.1 Functional Capability
     4.1.1 General
     4.1.2 Transponder Functions
     4.1.3 Transponder Control
4.2 Transponder Receiver Characteristics
     4.2.1 Receiver Center Frequency and Bandwidth
     4.2.2 Image Response
     4.2.3 Other Spurious Responses
     4.2.4 IF Pickup Rejection
     4.2.5 RF Rejection
     4.2.6 CW Discrimination
     4.2.7 Interrogation Modes
     4.2.8 Receiver Sensitivity an Minimum Triggering Levels
             (MTL)
     4.2.9 Decoding of Interrogations
     4.2.10 Sidelobe Suppression
     4.2.11 Pulse Decoder Tolerances
     4.2.12 Receiver Densensitization & Recovery Times
     4.2.13 Transponder Dead Time
     4.2.14 Mutual Suppression Pulses
     4.2.15 Pulse Duration Discrimination
     4.2.16 Random Triggering Rate
     4.2.17 Mode S Transponder Lockout Control
4.3 Transponder Transmitter Characteristics
     4.3.1 Reply Transmission Frequency
     4.3.2 Transmitter Power Output
     4.3.3 Transponder Emission Spectrum
     4.3.4 Reply Delay and Jitter
     4.3.5 ATCRBS Reply Rate Capability and Reply Rate Limit
             Control
     4.3.6 Transmitter Duty Cycle
     4.3.7 ATCRBS Mode A Reply Codes
     4.3.8 ATCRBS Mode C Pressure Altitude Transmission
     4.3.9 Mode S Replies
     4.3.10 Reply Pulse Interval Tolerance
4.4 Transponder Functional Test and Monitoring
     4.4.1 Functional Test
     4.4.2 Monitoring
4.5 Antenna Diversity Operation
     4.5.1 Antenna Selection
     4.5.2 Received Signal Delay Tolerance
     4.5.3 Differential Reply Delay
     4.5.4 Antenna Selection for Squitter Transmissions
     4.5.5 RF Port Transmitter Isolation
4.6 Mode S/Data Link Processor Interface Bus
     4.6.1 Basic Data Exchange Protocols
     4.6.2 Data Exchange Protocols for Uplink Message
     4.6.3 Data Exchange for Downlink Messages
4.7 Extended Length Message (ELM) Transfer
     4.7.1 Comm-C/Comm-D ELM Protocol
     4.7.2 ELM Data Transfer Interface Standards
     4.7.3 ELM Uplink Transactions
5.0 PROVISIONS FOR AUTOMATIC TEST EQUIPMENT
5.1 General
5.2 Unit Identification
     5.2.1 Pin Allocation
     5.2.2 Use of ATLAS Language
6.0 CONTROL PANEL DESIGN
6.1 Form Factor and Connector
6.2 Control Information Transfer
6.3 Control Functions
     6.3.1 Standby/On Switching
     6.3.2 Code Selectors
     6.3.3 "Ident" Pulse (SPI) On/Off
     6.3.4 Altitude Reporting On/Off
     6.3.5 Altitude Data Source Select
     6.3.6 Self Test On/Off
     6.3.7 TCAS Sensitivity Control
     6.3.8 TCAS Display Control
     6.3.9 Gillham Altitude Source Comparison Enable/Inhibit
6.4 Deleted
6.5 Deleted
6.6 Deleted
6.7 Control Panel Power and Initialization
6.8 Dual Transponder Control Panel Considerations
7.0 ANTENNA
7.1 Impedance and VSWR
7.2 Gain and Polarization
7.3 Power Rating
7.4 Radiation Pattern
7.5 Connector
7.6 L-band Systems Physical Isolation
7.7 Antenna Installation
     7.7.1 Total Interconnection Losses
8.0 BUILT-IN TEST EQUIPMENT (BITE)
8.1 Built-In Test Equipment (BITE) Function
8.2 BITE Display
8.3 Fault Monitor
8.4 Self-Test Initiation
8.5 Monitor Memory Output
ATTACHMENTS
1A Transponder Unit Connector Positioning
1B Control Unit Connector Positioning
1C Top Antenna
     Bottom Antenna
     Connector Layout - Mode S Transponder
2A Mode S Transponder Standard Interwiring
2B Notes Applicable To The Standard Interwiring
2C Transponder/Control Panel Wiring
2D Transponder/Data Link Processor Communications
     Protocol
2E ARINC 429 Low Speed Data Bus Definition
2F Altitude Source Selection Switching
3A ATCRBS Reply Code And Pulse Characteristics
3B Mode A Reply Code Combinations
3C Interrogation Pulses
3D DPSK Interrogations
3E Mode S Replies
3F Mode A Only and Mode C Only All-Call
4A DITS Display Control Word for TCAS
4B DITS Control Word for TCAS and Mode S Transponder
4C DITS Control Word for Mode S Transponder
4D DITS Control Word for TCAS and Mode S Transponder
4E DITS Control Word for TCAS and Mode S Transponder
4F DITS Control Word for TCAS and Mode S Transponder
4G DITS Control Word for TCAS and Mode S Transponder
4H Standard ARINC 429 Format for Bus W Word 5 -
     Transponder to TCAS
4I Standard ARINC 429 Format for Bus 1 Word 6 -
     Transponder to TCAS
5A Mode S Interrogation Formats
5B Mode S Reply Formats
5C Coding Functional Diagrams
5D Field Index Reference Notes
6 Independent Standard Message (SM) Protocols
7 Suppression Pulse System Characteristic
8 Typical Blade Antenna
9 Diversity Antenna Selection
10 Environment Test Categories
11 AEE C Letters 78-166/XPDR-12 and 78-175/XPDR-22
12 ELM Word Formats
APPENDICES
     Deleted

Defines an Air Traffic Control Radar Beacon System/Mode Select (ATCRBS) airborne transponder. The ATCRBS is made up of airborne transponders and ground interrogator-receivers, processing equipment and antenna systems. Mode S is a cooperative surveillance and communication system for air traffic control.