ARINC 575 : 68 SUPP 3

1.0
  1.1 Applicability and Nomenclature
  1.2 Function and Modes of Operation
  1.3 Regulatory Approval
  1.4 Interchangeability Requirements for the
                    Digital Air Data System
  1.5 Reliability
  1.6 Industry Views on Dual DADS Systems
2.0
  2.1 DADS Unit or "Computer"
  2.2 Indicators
  2.3 Pitot and Static Air System
  2.4 Temperature Sensor
  2.5 Control Panel
3.0 General
  3.1 Form Factors and Connections
    3.1.1 The DADS Computer Unit
    3.1.2 Indicators
  3.2 Weight
  3.3 Failure Warning Signals and Flag Alarms
    3.3.1 General
    3.3.2 Failure Warning Outputs
    3.3.3 Failure Warning Output Loads
  3.4 Standard Interwiring
  3.5 Power Circuitry
    3.5.1 Primary AC Power Input
    3.5.2 26 VAC Circuitry
    3.5.3 Circuit Protection
    3.5.4 Hold Enable Power
  3.6 Standard Electrical Signal Characteristics
                    and Signal Wiring
  3.7 Special Digital Altitude Output Signal
  3.8 Standard Temperature Sensor Characteristics
  3.9 Pneumatic Connections to the DADS Unit
  3.10 Static Source Error Correction (SSEC)
    3.10.1 General
    3.10.2 Standard SSEC Provisions and Wiring
    3.10.3 SSEC Function Characteristics
4.0
  4.1 Functional System Concept
  4.2 "Spare Space" Provisions for
                    ARINC Applications
  4.3 DADS Unit Sensor Design
  4.4 Pressure Limits
  4.5 System Leak Rate
  4.6 Computer "Pressure" Volume
  4.7 Mounting Provisions
    4.7.1 Sensor Unit Shock Mounting
    4.7.2 Indicator Mountings
  4.8 Interchangeability of Removable Sub-Units
  4.9 Service Adjustments
  4.10 Failure Indication and Flag System Design
    4.10.1 General
    4.10.2 Failure Warning Monitors
  4.11 Functional Test Provisions
  4.12 Radio Noise
  4.13 Static Source Error Correction (SSEC)
5.0 General
  5.1 Optional Functions
  5.2 Accuracy and Operating Ranges
  5.3 Function Threshold Sensitivity
  5.4 Standardized Output Signals
    5.4.1 Synchro Standards
    5.4.2 Potentiometer Standards
    5.4.3 Phase Reversing Voltage Standards
    5.4.4 Analog Voltage Signals
  5.5 Function Frequency Response
  5.6 Function Slewing Speeds
  5.7 Specific Requirements for Each Function
    5.7.1 General Standards
    5.7.2 Serial Digital Outputs
    5.7.3 Parallel Digital Output
    5.7.4 Overspeed Warning Output
    5.7.5 Analog Outputs
        5.7.5.1 Altitude
        5.7.5.2 Computed Airspeed
        5.7.5.3 Maximum Allowable Airspeed
        5.7.5.4 Mach
        5.7.5.5 Altitude Rate
        5.7.5.6 Hold Functions
        5.7.5.6.1 Airspeed Hold
        5.7.5.6.2 Altitude Hold
        5.7.5.6.3 Mach Hold
    5.7.6 Failure Warning Outputs
    5.7.7 Static Source Error Correction
  5.8 Inputs
    5.8.1 Baro-Correction
6.0
  6.1 Basic FAA Approval Requirements
  6.2 Additional Customer Needs
    6.2.1 Pressure Altitude
    6.2.2 Temperature
  6.3 "Customer Needs" For Dynamic
                    Temperature Compensation
7.0 General
  7.1 Indicator Design
  7.2 Lighting
  7.3 Flag Alarms
  7.4 Accuracy
  7.5 Indicator Self-Synchronization and
                    Range End Points
  7.6 Barometrically-Corrected Digital
                    Altitude Output
  7.7 Other Indicator Design Requirements
8.0
  8.1 General
  8.2 Characterized ADS System Output Signals for
                    Other Accessory Uses versus Separately
                    Generated Signals in those Accessories
9.0 Basic Digital Signal Standards
  9.1 Basic Serial Data Transmission Standards
    9.1.1 Basic Transmission System
    9.1.2 Data Transmission Circuit
    9.1.3 Word Synchronization
    9.1.4 Clock
  9.2 Word Structure
    9.2.1 Word Structure
    9.2.2 Standard Languages
        9.2.2.1 Binary Coded Decimal (BCD)
        9.2.2.2 Binary Words (BNR)
    9.2.3 Special Code Assignment for Sign and Status
                    Designation
        9.2.3.1 General
    9.2.4 Parity Checking
  9.3 Transmission Order
  9.4 Electrical Characteristics
    9.4.1 DC Signaling with Return to Zero Logic
    9.4.2 Signal Logic Levels
  9.5 Why New Digital Standards
    9.5.1 Output Load Capability
    9.5.2 Electromagnetic Noise Rejection
    9.5.3 Reverse Current Capability
  9.6 Digital Receiver
    9.6.1 Input Load Characteristics
    9.6.2 Electromagnetic Noise Rejection
    9.6.3 Digital Transmission Monitoring
ATTACHMENTS
 0 Notes Applicable to Standard Interwiring
   1-1 DADS Standards Interwiring to Computer
                    Bottom Plug DPD2 P1
   1-2 DADS Standards Interwiring to Computer
                    Top Plug DPD2 P2
   1-3 DADS Standards Interwiring to Computer
                    "Extra" Plug DPD P3
   2-1 DADS Connector Layout for Bottom Plug of
                    DPD-2 P1
   2-2 DADS Connector Layout for Top Plug of
                    DPD-2 P2
   2-3 DADS Connector Layout for Extra Plug P3
 3 DADS Computer Connector Locations
   4-1 "Standard Altitude Indicator" Pin Connections
   4-2 "Standard Mach/CAS Indicator" Pin Connections
   4-3 "Standard Vertical Speed Indicator" Pin
                    Connections
   4-4 "Standard Temperature Indicators" Pin
                    Connections
   4-5 "Standard True Air Speed Indicator" Pin
                    Connections
 5 Altitude Digitizer Standards (Signals to be
                    Used by ATC Transponders)
 6 Altitude Transmission Code
 7 System Configuration (Typical)
   8-1 Resistance Versus Temperature (DegC) for 500
                    Ohms, PCI, Platinum Sensing Elements
   8-2 Resistance Versus Temperature (DegC) for 500
                    Ohms, PCI, Platinum Sensing Elements
 9 DADS Performance Envelope
10 Typical Static Position Defect Correction
                    Curve
  11-1 Ground Rules
  11-2 DADS Static Source Error Correction Pin
                    Assignments and Connections
  11-3 Static Source Error Correction - Typical
                    System and Example of Jumpers
12 Summary of Outputs - ARINC 575 DADS
  13-1 DADS Computer Internal Wiring for Synchro
                    (or Equivalent) Outputs
  13-2 DADS Computer Internal Wiring for Rate and
                    Hold Outputs
  13-3 DADS Computer Internal Wiring for DC Analog
                    Outputs
14 Customer Needs For Output Isolation
  15-1 Summary of Digital Output Standards
  15-2 Digital Voltage Outputs
  15-3 Output Signal Timing Tolerances
  15-4 DADS Label/Address Code Assignments
  15-5 BCD Word Structure
  15-6 DADS Input and Output Circuit Standards
  15-7 Typical Examples of Standard Binary Data
                    Expressed Two's Complement Fractional
                    Notation
  16-1 VMO & MMO Curve Establishment
  16-2 VMO & MMO Program
  16-3 VMO & MMO Envelope
APPENDIX
                    Introduction to the Appendices
1 Reference Publications, Specifications and
                    Reports
2 Definitions, Symbols and Equations

Provides basic requirements for a Digital Air Data System (DADS) designed specifically for installation in subsonic commercial and transport type aircraft. Provides essential air-data information for the pilot's displays and for use by autopilot, other flight control and instrumentation systems.