MIL-STD-1553SpecificationTutorialV2.4July 2019

DOCUMENT HISTORYThe following table defines the history of this document. The description of changes/enhancements made to each version is defined in general terms.VersionCover DateCreated byDescription2.3Nov 2010B. WaldmannUpdate addresses2.4July 2019B. WaldmannUpdate CIAIM WorldwideAIM GmbHSasbacher Str. 2D-79111 Freiburg / GermanyPhone 49 (0)761 4 52 29-0Fax 49 (0)761 4 52 [email protected] GmbH – Munich Sales OfficeTerofalstr. 23aD-80689 München / GermanyPhone 49 (0)89 70 92 92-92Fax 49 (0)89 70 92 [email protected] UK OfficeCressex Enterprise Centre, Lincoln Rd.High Wycombe, Bucks. HP12 3RB / UKPhone 44 (0)1494-446844Fax 44 (0)[email protected] USA LLCSeven Neshaminy InterplexSuite 211 Trevose, PA 19053Phone www.aim-online.comNotice: The information that is provided in this document is believed to be accurate.No responsibility is assumed by AIM GmbH for its use. No license or rights are granted byimplication in connection therewith. Specifications are subject to change without notice. AIM GmbH 2019MIL-STD-1553 Tutorial

MIL-STD-1553Table of ContentsAbout This Manual .6Applicable Documents .7Industry Documents .7AIM Product Specific Documents .7MIL-STD-1553 Overview .8MIL-STD-1553 History and Application .81553B Hardware Components .11Bus Controller .11Remote Terminal .11Bus Monitor .121553 Cabling .121553 Coupling.12Direct Coupling.13Transformer Coupling.13Bus Topology .14MIL-STD-1760C.151553 Test Procedures.16Developmental Testing .16Design Verification .16Production Testing .16Systems Integration Testing .16Field/Operational Testing .17Table 2-III 1553 Test Plans for all Components . 17MIL-STD-1553B Specification Interpretation. 181.2.Scope .181.1Scope .181.2Application .18Referenced Documents .192.1Issue of Document .193.Definitions .204.General Requirements .22MIL-STD-1553 Tutorial

4.1Test and Operating Requirements . 224.2Data Bus Operation .224.3Characteristics .234.3.1 Data form .234.3.2 Bit Priority .234.3.3 Transmission Method . 244.4Terminal Operation .494.4.1 Common Operation . 494.4.2 Bus Controller Operation . 504.4.3 Remote Terminal .504.4.4 Bus Monitor Operation . 534.5Hardware Characteristics . 534.5.1 Data Bus Characteristics . 534.5.2 Terminal Characteristics . 584.6Redundant Data Bus Requirements . 644.6.1 Electrical Isolation .644.6.2 Single Event Failures . 644.6.3 Dual Standby Redundant Data Bus . 64Appendix .6510. General .6520. Referenced Documents .6730. General Requirements .67Notes.72Acronyms and Abbreviations .72Acronyms and Abbreviations (Cont'd) .73Appendix A – Notices Applied To MIL-STD-1553B . 74MIL-STD-1553 Notice Overview .74Notice 1 Overview .74Notice 2 Overview .74Notice 3 Overview .75Notice 4 Overview .75MIL-STD-1553 Tutorial

List of FiguresFigureTitlePage3-1Bus Components .183-2Data Encoding .243-3Word Formats .253-4Command and Status Sync .263-5Data Sync .333-6Information Transfer Formats.403-7Broadcast Information Transfer Formats . 413-8Intermessage Gap and Response Time . 473-9Data Bus Interface Using Transmforer Coupling . 483-10Data Base Interface Using Direct Coupling . 483-11Coupling Transmformer .553-12Terminal Input/Output Characteristics forTransformer Coupled Stubs and Direct Coupled Stubs . 583-13Output Waveform.623-10.1Possible Redundancy. .653-10.2Possible Redundancy. .65List of TablesTableTitle2-IMIL-STD-1553A and MIL-STD-1553B Requirements Comparison. .102-II1553 Cable Characteristics .122-III1553 Test Plans for all Components . 173-IAssigned Mode Codes .283-IICriteria for Acceptance or Rejection of a Terminal for the Noise Rejection Test . 61MIL-STD-1553 TutorialPage

IntroductionAbout This ManualThis manual was developed to provide a general overview of MIL-STD-1553 itsspecifications and applications.The first chapter provides a discussion of MIL-STD-1553, its history, application andoperational overview. Included is a reference to MIL-STD-1760C as it applies to WeaponStores Interface and its relationship to MIL-STD-1553B.The second chapter includes a complete annotated version of the MIL-STD-1553Bspecification and an interpretation of the specification contents. The specification is on thetop of each page and the AIM interpretation is located on the lower portion of the page.Notices 1 though 4, addendums to the MIL-STD-1553B specification, are summarized at theend of this manual, and have been incorporated into the specification discussed within thisdocument.AIM provides Commercial-Off-The-Shelf (COTS) products to design, produce, integrate, testand troubleshoot all systems and capabilities mentioned in this MIL-STD-1553 Tutorial aswell as for ARINC 429, STANAG 3910, MIL-STD-1760 Applications and Panavia Serial Link.Supported hardware platforms include PC/AT, PCI, Compact PCI, VME, VXI, and PMC.AIM software products also support full Remote Terminal production testing, full bus analysisand complete system emulation and test capabilities per MIL-STD-1553B specifications.For detailed [email protected] ail6

Applicable DocumentsThe following documents shall be considered to be a part of this document to the extentspecified herein.Industry DocumentsMIL-STD-464, Electromagnetic Environmental Effects Requirements for Systems, March 18,1997MIL-HDBK-1553A, Multiplex Application Handbook, March 23, 1995MIL-STD-1553B, Department of Defense Interface Standard for Digital Time DivisionCommand/Response Multiplex Data Bus, Notice 1-4, January 1996MIL-STD-1760C, Interface Standard for Aircraft/Store Electrical Interconnection System,March 2, 1999SAE AS4111, Validation Test Plan for the Digital Time Division Command/ResponseMultiplex Data Bus Remote Terminals, October 1998SAE AS4112, Production Test Plan for the Digital Time Division Command/ResponseMultiplex Data Bus Remote Terminals, January 1989SAE AS4113, Validation Test Plan for the Digital Time Division Command/ResponseMultiplex Data Bus Controllers, January 1989SAE AS4114, Production Test Plan for the Time Division Command/Response MultiplexData Bus Controllers, January 1989SAE AS4115, Test Plan for theMultiplex Data Bus System, January 1989DigitalTimeDivisionCommand/ResponseSAE AS4116, Test Plan for the DigitalMultiplex Data Bus Bus Monitors, September 1990TimeDivisionCommand/ResponseSAE AS4117, Test Plan for the Digital Time Division Command/ResponseMultiplex Data Bus Couplers, Terminators, and Data Bus Cables, March 1991AIM Product Specific DocumentsNoneMIL-STD-1553 Tutorial7

MIL-STD-1553 OverviewMIL-STD-1553B is the military specification defining a Digital Time DivisionCommand/Response Multiplexed Data Bus. The 1553 databus is a dual-redundant, bidirectional, Manchester II encoded databus with a high bit error reliability. All buscommunications are controlled and initiated by a main bus controller. Remote terminaldevices attached to the bus respond to controller commands.MIL-STD-1553B defines specifications for terminal device operation and coupling, wordstructure and format, messaging protocol and electrical characteristics.MIL-STD-1553 History and ApplicationMIL-STD-1553B was developed from thegrowing complexity of integrated avionicssystems and the subsequent increase in thenumber of discrete interconnects betweenterminal devices. Direct point-to-point wiringbecame complex, expensive and bulky,requiring definition of a multiplex data busstandard. The first draft of a standard in 1968by the Aerospace Branch of the Society ofAutomotive Engineers (SAE) laid thePoint-to-Point Wiring Schemefoundation for the US Air Force’s adoption ofMIL-STD-1553 in 1973.A tri-service version, MIL-STD-1553A was released in 1975, modified to MIL-STD-1553B in1978 and utilized in the Air Force F-16 and the United States (US) Army AH-64A ApacheAttack Helicopter. Notice 2, released in 1986 and superceded Notice 1 released in 1980, is atri-service standard for RT design specs and defines how some bus options are to be used.Notices 3 and 4 did not alter the contents of the standard, but only provided a title change.MIL-STD-1553B has become the internationally accepted networking standard for integratingmilitary platforms. Table 2-I shows the differences between MIL-STD-1553A andMIL-STD-1553B.Military services and contractors originallyadopted MIL-STD-1553 as an avionics databus due to its highly reliable, serial, 1Megabit per sec (Mbps) transfer rate andextremely low error rate of 1 word fault per10 million words, on a dual-redundantarchitecture. This reliability has provenequally effective oncommunicationData Bus Architecturenetworks in submarines, tanks, targetdrones, missile and satellite systems, landbased and launch vehicles, and space system including the current International SpaceStation and Shuttle programs.MIL-STD-1553 Tutorial8

MIL-STD-1553B defines the data bus structure for interconnection of up to 31 remoteterminal (RT) devices. A single controller device on the bus initiates the command/responsecommunication with the remote devices. The remote and control devices are interconnectedover two, separate buses. Normal operation involves only the primary bus with the secondarybus available as redundant backup in the event of primary bus damage or failure.Standardization of a set of specifications for a military data bus provides two majoradvantages:a. Significant size/weight savings of interconnected devices and cablingb. Reduced development and modification costs with compatible devices.MIL-STD-1553 Tutorial9

Table 2-I MIL-STD-1553A and MIL-STD-1553B Requirements ComparisonSpecification RequirementMIL-STD-1553AMIL-STD-1553BCable TypeJacketed, shielded twisted pair Jacketed, shielded twisted pairCable Shield Coverage – minimum 80%75%Cable Twist – minimum12 twists/foot4 twists/footCapacitance, wire to wire –maximum30 pF/ft30 pF/ftCharacteristic Cable Impedance(ZO)70 Ω 10% @ 1 MHz70-80 Ω 10% @ 1 MHzNominalCable Attenuation1 dB/100 ft @ 1 MHz1.5 dB/100 ft @ 1 MHzCable Length300 ft – maximumUnspecifiedCable TerminationCharacteristic ImpedanceNominal CharacteristicImpedance 2%Cable StubbingDirect Coupling 1 ftDirect Coupling 1 ftTransformer Coupling 1 – 20 ft Transformer Coupling 1 – 20 ftCable Coupling ShieldShielded coupler box75% coverage – minimumCoupling Transformer Turns RatioUnspecified1:141 3% with higher Turnson isolation resistor sideTransformer Open CircuitImpedanceUnspecified3 kΩ from 75 kHz – 1 MHzWith 1 V RMS sine waveTransformer Waveform IntegrityUnspecifiedDroop of 20% overshoot – maxRinging of 1 V peak – maxTransformer Common ModeRejectionUnspecified45 dB @ 1 MHzR 0.75 ZO 5%R 0.75 ZO 2%R 0.75 ZO 5%R 55 Ω 2%Fault IsolationIsolation Resistors in serieswith couplerDirect CoupledImpedance across bus with failedTransformer coupling component No less than 1.5 ZODirect couplingUnspecifiedNo less than 1.5 ZONo less than 110 ΩStub Voltage RequirementTransformer CoupledDirect Coupled1 V to 14 V peak to peak1.4 V to 20 V peak to peakMIL-STD-1553 Tutorial1 V to 20 V peak to peak1 V to 20 V peak to peak10

1553B Hardware ComponentsMIL-STD-1553B defines three types of terminal devices that are allowed on the bus:Primary Bus (A)Secondary Bus (B)a. Bus Controller (BC)b. Remote Terminal (RT)c. Bus Monitor (BM).BusControllerRemoteSubsystem(s)BusMonitorBus ControllerThe main function of the bus controller (BC) is to provide data flow control for alltransmissions on the bus. In addition to initiating all data transfers, the BC must transmit,receive and coordinate the transfer of information on the data bus. All information iscommunicated in command/response mode - the BC sends a command to the RTs, whichreply with a response.The bus controller, according to MIL-STD-1553B, is the “key part of the data bus system”and “the sole control of information transmission on the bus shall reside with the buscontroller, which shall initiate all transmission”. The bus can support multiple BCs, but onlyone can be active at a time.Normal BC data flow control includes transmitting commands to RTs at predetermined timeintervals. The commands may include data or requests for data (including status) from RTs.The BC has control to modify the flow of bus data based on changes in the operatingenvironment. These changes could be a result of an air-to-ground attack mode changing toair-to-air, or the failure mode of a hydraulic system. The BC is responsible for detecting thesechanges and initiating action to counter them. Error detection may require the BC to attemptcommunications to the RT on the redundant, backup bus.Remote TerminalThe remote terminal (RT) is a device designed to interface various subsystems with the 1553data bus. The interface device may be embedded within the subsystem itself, or be anexternal interface to tie a non-1553 compatible device to the bus. As a function of theinterface requirement, the RT receives and decodes commands from the BC, detects anyerrors and reacts to those errors. The RT must be able to properly handle both protocolerrors (missing data, extra words, etc) and electrical errors (waveform distortion, rise timeviolations, etc). RTs are the largest segment of bus components. RT characteristics include:a.b.c.Up to 31 remote terminals can be connected to the data busEach remote terminal can have 31 subadressesNo remote terminal shall speak unless spoken to first by the bus controller andspecifically commanded to transmitMIL-STD-1553 Tutorial11

Bus MonitorThe bus monitor (BM) listens to all messages on the bus and records selected activities. TheBM is a passive device that collects data for real-time or post capture analysis. The BM canstore all or portions of traffic on the bus, including electrical and protocol errors. BMs areprimarily used for instrumentation and data bus testing.1553 CablingThe MIL-STD-1553B definition of a data busis “a twisted-shielded pair transmission linemade up of a main bus and a number ofattached stubs”. Shielding limits signalinterference from outside sources and thetwisted pair maintains message integritythrough noise canceling.MIL-STD-1553B specifies that all devices inthe system will be connected to a redundantpair of buses, providing an alternate datapath in the event of damage or failure of theprimary bus path. Bus messages only travelon one of the buses at a time, determined bythe bus controller.Table 2-II 1553 Cable CharacteristicsCable TypeTwisted Shield PairCapacitance30pF/ft maxCable Impedance70-85 Ω at 1 MHzCable Attenuation1.5 dB per 100 ft at 1 MHz maxTwist Ratio4 per foot minShield Coverage75% minCable Termination Cable Impedance 2%Properly terminating the main data bus on each end makes the bus appear like an infiniteline. Stub loading effects can be minimized on the bus by properly designed coupling. Table2-II lists the 1553 cable characteristics1553 CouplingCoupling connects a terminal device to the main data bus via interconnecting buses calledstubs. Connecting terminals create a load on the main bus, creating impedance mismatchesand resultant signal reflections that can distort and degrade signal quality on the bus. Systemerror rate performance and good signal to noise ratio require a balance between stubimpedance being low enough to provide adequate terminal signal levels but high enough toreduce signal distortion from reflections. MIL-STD-1553B allows two methods of couplingterminal devices to the main bus:a.Direct couplingb.Transformer coupling.MIL-STD-1553 Tutorial12

Direct CouplingDirect coupling connections are wired directly to the bus cabling. Theisolation resistors and transformer are internal to the terminal device, notrequiring additional coupling hardware. Direct coupling connections canonly be used with stub lengths of less than 1 foot.Isolation resistors provide some protection for the main bus in the event ofa stub or terminal short, but MIL-STD-1553B cautions the use of directcoupling because a terminal short could disable the entire bus. Direct stubscan also cause significant impedance mismatches on the bus.RemoteTerminalTransformer CouplingTransformer coupling utilizes a second isolation transformer, locatedexternal to the terminal device, in its own housing with the isolationresistors. Transformer coupling extends the stub length to 20 feet andprovides electrical isolation, better impedance matching and higher noiserejection characteristics than direct coupling. The electrical isolationprevents a terminal fault or stub impedance mismatch from affecting busperformance.RemoteTerminalMIL-STD-1553 Tutorial13

Bus TopologyBus topology refers to the physical layout and connections of each device attached to thedata bus. Single level topologies are the most basic, easy to design and widely implementedlayouts with all terminal devices connected to a single bus.RTRTBMBus A – PrimaryBus B – SecondaryBCRTMultiple level topologies are designed by interconnecting single level buses so data from onebus can be transferred on another bus. Buses interconnected in a multiple level topology canhave equal control over data flow, which helps retain autonomy for each bus with thegreatest isolation between them. A hierarchical format between multiple level busesestablishes local (subordinate) buses and global (superior) buses with the global bus havingcontrol over local, subordinate buses.MIL-STD-1553 Tutorial14

MIL-STD-1760CMIL-STD-1760C, released April 15, 1991 defines implementation requirements for theAircraft/Store Electrical Interconnection System (AEIS) between aircraft and stores. A store isany external device attached to the aircraft and includes permanent devices – ECM,LANTIRN, fuel tanks – and devices designed to separate – bombs, missiles, etc.MIL-STD-1760C states “the data bus interface shall comply with the requirements of MILSTD-1553” with some additional requirements. In this case, the 1553 bus is the controllingbus over the subordinate 1760 AEIS bus. That 1760 bus may then control a 1553 bussystem within a store to communicate directly with weapons, navigational aids orcommunications subsystems.Interfaces Controlled by 1760CASI – Aircraft Station InterfaceCSI – Carriage Store InterfaceCSSI – Carriage Store Station InterfaceMSI – Mission Store InterfaceThe Aircraft Station Interface (ASI) is the connection to the aircraft. Umbilical cablingconnects the ASI to the store connector, the Mission Store Interface (MSI). The ASI can alsoconnect – through an umbilical cable – to a Carriage Store Interface (CSI) to tie in multiplemission stores. Carriage Store Station Interfaces (CSSI) then connects to MSIs via umbilicalcables.MIL-STD-1553 Tutorial15

Mission stores contain embedded 1553 RTs that must be capable of BC-RT, RT-BC and RTRT message transfers with the aircraft functioning as the bus controller. Dynamic bus controlis not allowed on a MIL-STD-1760C bus design.1553 Test ProceduresTesting MIL-STD-1553B components validate the functional capability of the bus design.Testing the design of a bus requires testing message formats, mode commands, status wordbits and coupling techniques as they apply to each remote terminal, bus controller andmonitor device. Five levels of testing have been developed to verify MIL-STD-1553B busdesign compliance:a. Developmental Testingb. Design Verificationc. Production Testingd. Systems Integration Testinge. Field/Operational Testing.Developmental TestingDevelopmental Testing is implemented at the circuit level to determine operational capabilityof the circuit design. Standard test techniques also validate operating characteristics over therequired environmental operating range – i.e. temperature, humidity, vibration, etc.Design VerificationDesign Verification is carried out on pre-production prototypes to insure 1553 compliance, aswell as systems specifications on the design unit itself. This testing level verifieshardware/software requirements before production begins.Production TestingProduction Testing is performed on production equipment as a final Quality Assurance checkor during the production process on subassembly items. Often applying a subset of thedesign verification tests, Production Testing verifies circuit operation and proper sequenceoperations such as error message validation and mode code operation.Systems Integration TestingSystems Integration Testing is applied while integrating bus components into a system andinsures interoperability of the joined components. During Systems Integration Testing,network hardware and software are combined and assessed to insure proper data flowcontrol.MIL-STD-1553 Tutorial16

Field/Operational TestingField/Operational Testing is implemented as a final design test of the system under actualoperating conditions. Known as Developmental Test/Operational Test – DT/OT – this level oftesting verifies operational integrity of the components/system in installed, fully functional busnetworks.The Society of Automotive Engineers (SAE) in conjunction with the government hasdeveloped a series of Test Plans for all 1553 components as listed in Table 2-III.Table 2-III 1553 Test Plans for all ComponentsTest PlanDocument NumberRemote Terminal Validation Test Plan – Section 100MIL-HDBK-1553ARemote Terminal Validation Test PlanSAE AS4111Remote Terminal Production Test PlanSAE AS4112Bus Controller Validation Test PlanSAE AS4113Bus Controller Production Test PlanSAE AS4114Data Bus System Test PlanSAE AS4115Bus Monitor Test PlanSAE AS4116Bus Components Test PlanSAE AS4117MIL-STD-1553 Tutorial17

MIL-STD-1553B Specification InterpretationThe following numbered sections are lifted from MIL-STD-1553B with Notices 1-4incorporated. All Notice 1 changes were superceded by Notice 2 changes. Notice 2 changesare noted with two asterisks (**). (Notices 3 and 4 do not affect the body of the text.) Beloweach group of numbered sections is an interpretation provided by AIM to aid the reader in abetter understanding of the MIL-STD-1553B specification.1.Scope1.1ScopeThis standard establishes requirements for digital, command/response, time divisionmultiplexing (Data bus) techniques**. It encompasses the data bus line and its interfaceelectronics illustrated on Figure 3-1, and also defines the concept of operation andinformation flow on the multiplex data bus and the electrical and functional formats to beemployed.1.2ApplicationWhen invoked in a specification or statementof work, these requirements shall apply tothe multiplex data bus and associatedequipment which is developed either alone oras a portion of a** weapon system orsubsystem development. The contractor isresponsible for invoking all the applicablerequirements of this Military Standard andany and all su

MIL-STD-1553 Tutorial 9 MIL-STD-1553B defines the data bus structure for interconnection of up to 31 remote terminal (RT) devices. A single controller device on the bus initiates the command/response communication with the remote devices. The remote and con