ARINC 725-2 : 1984

1.0 INTRODUCTION AND DESCRIPTION
   1.1 Purpose
   1.2 Summary of Operational Characteristics
   1.3 Brief Description of the System Components
   1.4 Unit Description
      1.4.1 Symbol Generator/Processor Unit (SG)
      1.4.2 Control Panel (CP)
      1.4.3 Display Unit (DU)
   1.5 Interchangeability
      1.5.1 General
      1.5.2 Interchangeability Desired for the ARINC 725 EFI
   1.6 Regulatory Approval
2.0 INTERCHANGEABILITY STANDARDS
   2.1 Introduction
   2.2 Form Factor, Connectors and Index Pin Coding
      2.2.1 Symbol Generator/Processor Unit (SG)
      2.2.2 Control Panel (CP)
      2.2.3 Form Factor "A" Display Unit
      2.2.4 Form Factor "B" Display Unit
      2.2.5 Form Factor "C" Display Unit
      2.2.6 Form Factor "D" Display Unit
      2.2.7 Form Factor "E" Display Unit
   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 Environmental Conditions
      2.5.1 Thermal Interface and Design
         2.5.1.1 SG
         2.5.1.2 CP
         2.5.1.3 Display Units
   2.6 Weights
   2.7 System Functions and Signal Characteristics
   2.8 Grounding and Bonding
3.0 SYSTEM DESIGN CONSIDERATIONS
   3.1 General
   3.2 Display Units
      3.2.1 Display Design Criteria
         3.2.1.1 Display Visibility
         3.2.1.2 Line Definition
         3.2.1.3 Display Refresh Rate
         3.2.1.4 Absolute Position Accuracy
         3.2.1.5 Relative Position Accuracy
         3.2.1.6 Allowable Jitter
         3.2.1.7 Phosphor Protection
         3.2.1.8 Positional Stability
         3.2.1.9 Dimensional Stability
         3.2.1.10 Focus
         3.2.1.11 Linearity
         3.2.1.12 Off Centering
         3.2.1.13 Uniformity of Brightness
         3.2.1.14 Brightness Control
         3.2.1.15 Convergence
      3.2.2 Cathode Ray Tube Assembly Design Criteria
         3.2.2.1 Pilot Protection
         3.2.2.2 X-Ray Radiation
         3.2.2.3 Antireflection Coating
         3.2.2.4 Viewing Angle
   3.3 Symbol Generator/Processor Unit (SG)
      3.3.1 General Considerations
      3.3.2 Primary AC Power for the SG
      3.3.3 SG Power Dissipation
   3.4 Control Panel (CP)
      3.4.1 General Considerations
      3.4.2 Mode Select and Controls
      3.4.3 Integral Lighting
      3.4.4 Primary AC Power for the CP
   3.5 System Interfaces
      3.5.1 Data Source Switching
      3.5.2 SG Digital Inputs
         3.5.2.1 Control Panel (CP) Input - Flight
         3.5.2.2 Thrust Control Computer (TCC) Input
         3.5.2.3 Flight Management Computer (FMC) Input
         3.5.2.4 Flight Control Computer (FCC) Input
         3.5.2.5 Inertial Reference System Input
         3.5.2.6 Instrument Landing System (ILS) Input
         3.5.2.7 Distance Measurement Equipment (DME) Input
         3.5.2.8 VHF Omnirange (VOR) Input
         3.5.2.9 Low Range Radio Altimeter (LRRA) Input
         3.5.2.10 Weather Radar (WXR) Input
         3.5.2.11 Air Data System (ADS) Input
         3.5.2.12 Automatic Direction Finder (ADF) Input
         3.5.2.13 Microwave Landing System (MLS) Input Provisions
         3.5.2.14 Flight Augmentation Computer (FAC) Input
         3.5.2.15 Flight Warning Computer Input
         3.5.2.16 Glare Shield Controller (GSC) Input
      3.5.3 SG Analog Outputs
      3.5.4 SG Digital Output (Maintenance Monitor)
      3.5.5 CP Digital Outputs
      3.5.6 CP Analog Inputs
      3.5.7 CP Analog Outputs
         3.5.7.1 CP Discrete Outputs
      3.5.8 Display Unit Analog Inputs
      3.5.9 Display Unit Analog Outputs
   3.6 "Integrity Monitoring" and "Failure Warning"
                   on Display
      3.6.1 General
      3.6.2 Internal Monitoring Concept
      3.6.3 Primary Information Concerning the Integrity
                   Monitoring
   3.7 "Built-In-Push-To-Test" Equipment
4.0 STANDARD SIGNAL CHARACTERISTICS
   4.1 General Accuracy and Operating Ranges
      4.1.1 Resolution
      4.1.2 Standardized Signaling
         4.1.2.1 Digital Data Standards
         4.1.2.2 Standard "Applied Voltage"
         4.1.2.3 "Standard Ground" Signals
   4.2 Data Signals
      4.2.1 Digital Data Inputs
         4.2.1.1 ARINC 704/705 IRS/AHRS 1 & 2
         4.2.1.2 ARINC 706 Air Data System 1 & 2
         4.2.1.3 ARINC 702 Flight Management Computer 1 & 2
         4.2.1.4 ARINC 701 Flight Control Computer 1 & 2, 3
         4.2.1.5 ARINC 703 Thrust Control Computer 1 & 2
         4.2.1.6 ARINC 710 ILS 1 & 2
         4.2.1.7 ARINC 711 VOR 1 & 2
         4.2.1.8 ARINC 709 DME 1 & 2
         4.2.1.9 ARINC 707 Radio Altimeter 1 & 2
         4.2.1.10 ARINC 712 ADF 1 & 2
         4.2.1.11 ARINC 726 Flight Warning Computer 1 & 2
         4.2.1.12 ARINC 727 MLS Receiver 1 & 2
         4.2.1.13 ARINC 708 Weather Radar 1 & 2
         4.2.1.14 Flight Augmentation Computer (FAC) 1 & 2
         4.2.1.15 Glare Shield Controller (GSC) 1 & 2
      4.2.2 Digital Data Outputs
   4.3 Discrete Inputs
      4.3.1 SG Function Program Pins
      4.3.2 SG Source Select Pins
      4.3.3 CP Function Program Pins
      4.3.4 DU Source Select Pins
   4.4 Discrete Outputs
5.0 CONTROL PANEL DESIGN
   5.1 General
   5.2 Form Factors and Connector
   5.3 Cooling
   5.4 Panel Illumination
   5.5 Power Supply for CP Operation
   5.6 Discrete Word Format
   5.7 Liquid Spillage Protection
   5.8 Digital Data Output
6.0 PROVISIONS FOR AUTOMATIC TEST EQUIPMENT
   6.1 General
   6.2 Unit Identification
      6.2.1 Pin Allocation
      6.2.2 Use of ATLAS Language
ATTACHMENTS
    1 Notes Applicable to Standard Interwiring
    2 Standard Interwiring
    3 Top Insert Pin Usage
    3A Middle Insert Pin Usage
    4 ARINC 725 SGConnector Layout
    5 EFI Symbol Generator Envelope
    6 Control Panel Outline Drawing
    7 Typical Remote Light Sensor Outline (Deleted)
    8-1 Form Factor "A" Display
    8-2 Form Factor "B" Display
    8-3 Form Factor "C" DU Envelope
    8-4 Form Factor "D" DU Envelope
    8-5 Form Factor "E" DU Envelope
    9 Typical EFI Interface Diagram
    10 Environmental Test Categories
    11 Electronic Flight Instrument Interface with
                   the Flight Management Computer
    12 Electronic Flight Instrument Interface with
                   the Flight Warning Computer
    13 Electronic Flight Instrument Interface with
                   the Weather Radar
    14-1 Maintenance Monitor Digital Outputs
    14-2 Maintenance Monitor
APPENDIX
    1 Bibliography of the AEEC ARINC 725 Electronic
                   Flight Instrument Project (EFI)

Describes the features of a color EFI system for installation in commercial transport aircraft.