Table of Contents
1INTRODUCTIONANDDESCRIPTION
1.1Purpose
1.1.1RelationshiptoOtherDocuments
1.2FunctionsandModesofOperation
1.2.1BasicModesofOperation
1.2.2SpecificFunctionsandOutputs
1.3Reliability
1.4UnitDescription
1.4.1InertialReferenceUnit(IRU)
1.4.2ControlandDisplayUnit(CDU)
1.4.3"GenerationInterchangeability"Considerations
1.5Interchangeability
1.6RegulatoryApproval
1.7TestabilityandMaintainability
2.0INTERCHANGEABILITYSTANDARDS
2.1FormFactors,Connectors,andIndexPinCoding
2.1.1InertialReferenceUnit(IRU)
2.1.2ControlandDisplayUnit(CDU)
2.1.3ControlandDisplayUnit(CDU)(CustomerOption)
2.2InputandOutputSignalCharacteristics
2.3StandardInterwiring
2.4PowerCircuitry
2.4.1ACPowerInput(Primary)
2.4.2BackupDCPower
2.4.3GroundingandBonding
2.5Weights
2.6ThermalInterfaceandDesign
2.6.1IRU
2.6.2CDU
2.7EnvironmentalTestCategories
2.8InertialReferenceUnitMounting
2.8.1SensorUnitOrientation
2.8.2MountingTolerances
2.9AirplaneDynamicEnvironment
2.10InitializationProtocolHeadingSet
3.0SYSTEMDESIGNCONSIDERATIONS
3.1General
3.1.1RangeofAttitudeOperation
3.1.2RelationshiptoRemoteComputers
3.1.3AlignmentStatus
3.1.4RangeofGeographicOperation
3.1.4.1World-WideNavigation
3.1.4.2Non-PolarNavigation
3.1.4.3ExtendedMAGVAR
3.2BasicModesofSystemOperations
3.2.1OFF
3.2.2Alignment(ALIGN)
3.2.3Navigation(NAV)
3.2.4AttitudeReference(ATT)
3.3Outputs
3.3.1AnalogOutputs
3.3.2DigitalOutputs
3.3.2.1BasicOutput
3.4IntegrityMonitoringandSelf-Test
3.4.1General
3.4.2IntegrityMonitorsandFailureWarningOutputs
3.4.2.1FailureWarning
3.4.2.2WarningOutputs
3.4.2.2.1FailureWarningOutputs
3.4.2.2.2MonitorIntegrity
3.4.3Built-InTestEquipment(BITE)
3.4.4Self-Test
3.5InertialReferenceSystemAccuracy
3.5.1General
3.5.2Mark1
3.5.3Mark2
3.6InitializationProtocol
3.7HeadingSet(ATTitudeModeOnly)
3.8IRSUpdatingwithGNSSData
4.0STANDARDSIGNALCHARACTERISTICS
4.1GeneralAccuracyandOperatingRanges
4.1.1Resolution
4.1.2StandardizedSignaling
4.1.2.1DigitalDataStandards
4.1.2.2Standard"AppliedVoltage"
4.1.2.3"StandardGround"Signal
4.1.2.4StandardDiscreteInput
4.1.2.5StandardDiscreteOutput
4.2DataSignals
4.2.1DigitalDataInputs
4.2.1.1InitializationDataEntry
4.2.1.2RemoteInitializationDataEntry
4.2.1.3RemoteInitializationDataEntry(Alternate)
4.2.1.4DigitalAirDataInputPorts
4.2.1.5GNSSInputPorts
4.2.1.6DifferentialGPSandIntegrityMonitorInputs
4.2.2DigitalDataOutputs
4.3ControlSignals
4.3.1DigitalControlInputs
4.3.2DigitalControlOutputs
4.3.3DiscreteInputs
4.3.3.1ControlDiscretes
4.3.3.2DADSDiscretes
4.3.3.3Air/GroundDiscrete
4.3.4DiscreteOutputs
4.3.4.1IRSFailureWarning
4.3.4.2"OnBackupPower"Operation
4.3.4.3LowBackupPowerVoltageIndication
4.3.4.4Align/NotReadyIndication
4.3.4.5CDU"OFF"Switch
4.3.5GNSSTimeMarkInput
5.0CONTROL/DISPLAYUNIT(CDU)DESIGN
5.1General
5.2FormFactorsandConnector
5.3Cooling
5.4PanelIllumination
5.5AnnunciatorDimming
5.6PowerSupplyforCDUOperation
5.7CDUInterfaceSummary
5.7.1CDUInputs
5.7.2CDUOutputs
5.8LiquidSpillageProtection
5.9DisplayTest
6.0PROVISIONSFORAUTOMATICTESTEQUIPMENT
6.1General
6.2UnitIdentification
6.2.1PinAllocation
6.2.2UseofATLASLanguage
0IRSDataUsage
1NotesApplicabletoStandardInterwiring
2StandardInterwiring
3StandardInterwiring-TopandMiddleInsertPinUsage
4-1IRURearConnectorView
4-2InertialReferenceUnit(IRU)-DimensionsandTolerances
4-3IRUMountingTray-GeneralLayout
4-4TrayFrontView
5-1CDUConnectorPinLayout/Usage
5-2Control/DisplayUnit(CDU)OutlineandMounting
6704IRSBlockDiagram
6-1743GPS/704IRSBlockDiagram
6-2743GPS/704IRSInterconnectDiagram
7NavigationalMnemonicsDefined
8EnvironmentalTestCategories
9DigitalControlWordFormat
10IRSDigitalSummary-Inputs/Outputs
10-1AdditionalARINC429OutputsforARINC704(IRS)WhenUsed
withARINC743A(GNSS)
10-2DiscreteWordOutputsfromARINC704(IRS)WhenUsed
withARINC743A(GNSS)
11CDUAnnunciatorDisplayDimming
12-1AdditionalARINC429InputsforARINC704(IRS)WhenUsed
withARINC743A(GNSS)
12-2DiscreteARINC429InputDefinitionforARINC704(IRS)When
UsedwithARINC743A(GNSS)
13GPSTimeMark
APPENDICES
1BibliographyoftheAEECARINC704InertialReferenceSystem
Project
2Non-StandardApplications Abstract
Describes the desired performance of inertial measuring devices and associated electronics specifically designed for installation in commercial transport aircraft. This system provides the basic outputs for aircraft angular rate and acceleration, and computed outputs of altitude, true heading, velocity and present position in a 10 MCU form factor.
