SAE AIR 6234-2016 Handbook Standard Electrical and Logical Interface for Airborne Fuzing Systems.pdf

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4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on thisTechnical Report, please visithttp:/standards.sae.org/AIR6234AEROSPACEINFORMATION REPORTAIR6234Issued 2016-11Handbook: Standard Electrical and Logical Interface

5、for Airborne Fuzing SystemsRATIONALESAE AS-1 Technical Committee Aircraft Systems and System Integration, formed SAE AS-1B6, Fuze Systems Task Group, to generate an Aerospace Standard (AS) to support interoperability and interchangeability of airborne weapons and their fuzing systems. This effort wa

6、s initiated in response to a request made to the SAE AS-1 Technical Committee by the North Atlantic Treaty Organization (NATO) Air Armament Panel for AS-1 to undertake a study or series of studies related to airborne weapons fuzing system standardization.As a result of this request, Aerospace Standa

7、rd AS5716 was published in February 2010 and subsequently updated as AS5716A in December 2012, providing definitions for a standard interface for fuzing system incorporated into weapons using MIL-STD-1760, aircraft to weapon interfaces as this is the interface generally employed for all modern airbo

8、rne weapons of NATO countries. This Handbook provides background information regarding the rationale and principles of the standard and has been written to give guidance on implementation of the standard. FOREWORD The information in this Handbook is intended to provide explanation and rationale for

9、the requirements contained in AS5716 and to provide equipment design guidance on implementation of the requirements. The original intention was to delay the first issue of the Handbook until information could be included that was based on actual design experience. However, no such information has be

10、en received to date. It is intended therefore, that future issues of the Handbook will incorporate such information as and when it becomes available. SAE INTERNATIONAL AIR6234 Page 2 of 50TABLE OF CONTENTS1. SCOPE 42. REFERENCES 42.1 Applicable Documents 42.1.1 SAE Publications. 42.1.2 NATO Publicat

11、ions 42.1.3 US Government Publications 42.1.4 TIA Publications 42.1.5 ISO Publications 52.2 Definitions . 52.3 Abbreviations 52.4 Nomenclature 63. GENERAL INFORMATION. 63.1 General Interface Information . 63.1.1 Functional Interface Classes. 73.1.2 Interface Connections . 83.2 Digital Communication

12、93.2.1 Fuzing System Serial Data Interface 93.2.2 Post Release Environment Sensor Serial Data Interface. 103.3 Power Requirements. 103.3.1 Port 1 Power, Port 2 Power and Port 3 Power and Returns. 103.4 Discrete Signal Requirements 113.4.1 Release Consent Monitor 113.4.2 Release Indication. 113.4.3 E

13、OD Arm State Monitor and Return . 113.4.4 Initiation Inhibit 123.4.5 Target Detection Device Signal and Return 123.4.6 Post Release Environment Sensor Signal and Return . 123.4.7 Address Bit Discretes 123.5 Reference Lines 133.5.1 Signal Return 133.5.2 Structure Ground. 133.6 Sequence of Operations

14、 134. DETAILED REQUIREMENTS 134.1 Detailed Requirements on the Weapon 134.1.1 Connector Type, Contact Identification, and Interface Functionality 134.1.2 Requirements for Digital Communication . 144.1.3 Power Requirements. 144.1.4 Requirements for Discrete Signals . 174.1.5 Reference Line Requireme

15、nts 204.2 Detailed Requirements on the Fuzing System . 204.2.1 Connector Type, Contact Identification, and Interface Functionality 204.2.2 Requirements for Digital Communication . 214.2.3 Power Requirements. 214.2.4 Requirements for Discrete Signals . 264.2.5 Reference Line Requirements 294.3 Fuzing

16、 System Serial Data Interface 304.3.1 Overview . 304.3.2 General Requirements 324.3.3 Communications Protocol . 344.3.4 Examples of Protocol Usage. 404.4 Post Release Environment Sensor Serial Data Interface. 404.4.1 Overview . 404.4.2 General Requirements 414.4.3 Communications Protocol . 434.4.4 D

17、etailed Requirements 454.4.5 Example of Protocol Usage 46SAE INTERNATIONAL AIR6234 Page 3 of 504.5 Sequence of Operations . 464.5.1 Overview . 464.5.2 Carriage Phase Operations 464.5.3 Release Preparation Phase Operations . 474.5.4 Release two wires are used for fuzing system to weapon communication

18、The four wire configuration was used in order to allay safety fears that a fuzing system main housing or Target Detection Device (TDD) on the data bus could erroneously send a valid message to another fuzing system main housing and alter its safety critical data.By using the four wire configuration

19、 only the weapon can send data to any of the fuzing system data receivers.In order to allow a backwards compatibility with existing two wire communication links, where safety is a lesser concern or is achieved by other means, the protocol has been defined so that it is compatible with half duplex c

20、ommunications over a two wire interface should the need arise.The interface is designed as a master-slave communication. It is therefore the responsibility of the weapon to initiate any communication, such as commands or status requests. This approach is already commonly used in weapon/fuzing system

21、 interfaces.SAE INTERNATIONAL AIR6234 Page 10 of 50WpnF 1ExtTDDPRES 1FS1F 2ExtTDDPRES 2FS2F 3Int TDD PRES 3FS3- - - - -2 x EIA-485 (EIA-422)- ( - )Figure 1 - Possible multi fuzing system communications architecture3.2.2 Post Release Environment Sensor Serial Data InterfaceThe Post Release Environmen

22、t Sensor Serial Data Interface was introduced in AS5716A, and provides unidirectional data from the PRES to the fuzing system main housing. It is standardized for Class 3 interfaces only, but can be used for Class 1and Class 2, if required. The use of a unidirectional interface is intended to establ

23、ish a constant stream of PRES data with a new data frame every 10 milliseconds. There are multiple benefits to this approach:x The data stream allows a constant monitoring of the PRES state.x Any change of PRES state would be expected to be of a minimum duration of several data frames. Thus temporar

24、y glitches or single erroneous data frames can be detected and ignored.x The 10 millisecond interval allows for short reaction times during the arming process.3.3 Power RequirementsNo comment.3.3.1 Port 1 Power, Port 2 Power and Port 3 Power and ReturnsThe standard provides for three distinct power

25、supplies. These supplies have been defined to allow the fuze designer to accommodate safety requirements aimed to ensure safety.SAE INTERNATIONAL AIR6234 Page 11 of 50Port 1 Power is defined as the power available to support fuzing system communications and fuzing system general operation prior to t

26、he weapon release sequence.Port 2 Power is aimed to support the fuzing system prior to and during the release sequence, and communications and functionality during weapon flight post release.Port 3 Power is specifically defined to allow the use of environmentally derived power sources for arming aft

27、er separation. Voltage definitions on the three supplies are intended to permit the Port 2 Power to support communications, but to prevent Port 2 Power from being able to be used to arm the fuzing system. For Class 1 interfaces it is assumed that arming power is provided through an additional connec

28、tion not standardized in this standard; Port 3 Power as defined here may be used.Because the Port 3 Power source may be intermittent during flight (because weapon maneuvers may shield an air generator, for example), the requirements on the functionality of the fuzing system in response to the presen

29、ce of the power source were relatively complex to define. The intent of the standard is that the fuzing system should be able to arm if the power source is present. However, it is recognized that long interruptions of the power source will limit the ability of the fuzing system to arm or remain arme

30、d. 3.4 Discrete Signal RequirementsThe interface provides connections for Release Consent Monitor, Release Indication, Explosive Ordnance Disposal (EOD) Arm State Monitor, Initiation Inhibit, Target Detection Device Signal, Post Release Environment Sensor Signal, and Address Bit Discretes connection

31、s. 3.4.1 Release Consent MonitorThe Release Consent Monitor provides an indication to the fuzing system of the status of the Release Consent signal at the aircraft-store interface (see MIL-STD-1760). As defined in MIL-STD-1760, this signal provides an independent confirmation to the weapon, and subs

32、equently to the fuzing system, that the information being sent on the data bus effectively has the direct authority of the pilot.As this signal is used by the fuzing system for safety confirmation, it is essential that the signal has as simple as possible a path from the MIL-STD-1760 interface to th

33、e fuzing system. It would not be acceptable from a safety perspective for the signal to be weapon sourced, for example, in a weapon controller.3.4.2 Release IndicationThe Release Indication signal is included in the interface to provide the fuzing system with an indication of the mated statusof the

34、umbilical connector between the weapon and platform. The original intention was to define an interface that enabled the fuzing system to use the same circuit as that employed by the weapon control system, i.e., monitor the current path associated with the data bus address lines. However, review of t

35、he methodologies used for this, and the nature of the MIL-STD-1760 address line electrical specification, meant that it would be difficult to define a universally adoptable approach to safely monitoring these lines in conjunction with any MIL-STD-1760 weapon controller. It was decided therefore to r

36、etain the concept of using a current loop but define a single set of parameters for the required signal levels.As with the Release Consent interface, care in the weapon design is required to ensure that the Release Indication interface is as simple as practicable, but still indicates unambiguously t

37、hat the weapon either is or is not connected to the aircraft. Itshould if possible directly reflect the state of the MIL-STD-1760 address lines.3.4.3 EOD Arm State Monitor and ReturnIn order to provide EOD personnel with a standardized interface to detect the armed/ safe status of the fuzing system,

38、 the standard has defined a pair of contacts that are intended for EOD use only. These contacts are located deliberately at the center of the connector to simplify use.The electrical interface has been designed so that it can be used with both out-of-line and in-line arming systems with minimum risk

39、 to EOD personnel. SAE INTERNATIONAL AIR6234 Page 12 of 50For out-of-line fuzing systems, this will allow the monitoring of two characteristic resistances, where one value indicates that the system is in a safe state and a different value indicates an armed state.For in-line fuzing systems, the arme

40、d status is detected by sensing the presence of voltage on the firing capacitor. The EOD interface allows for voltage monitoring in addition to the resistance monitoring for out-of-line designs.For inline fuzing systems, the standard implicitly requires a 1000:1 ratio between the voltage on the high

41、 voltage firing capacitor and the voltage available at the EOD connections. Currently, the maximum no fire voltage for inline fuzing systems is 500 V dc (as per STANAG 4187 and MIL-STD-1316), which would create 0.5 V dc at the EOD lines. This can be achieved by designing a passive resistor network,

42、which safely allows direct monitoring, but prevents any charging of the firing capacitor through the EOD Arm State Monitor lines.When the fuzing system type is unknown, it is anticipated that EOD personnel can either initially confirm that no voltage is present and then confirm from the measured res

43、istance whether the fuzing system has no EOD Arm State Monitor or is in-or out-of-line and its armed status; or, they can use a safety ohmmeter first to attempt to measure the resistance, bearing in mind that if the fuzing system incorporates an inline design, then a voltage may be present on the co

44、ntacts that will affect the ohmmeter function.3.4.4 Initiation InhibitIn order to provide a rapid and direct mechanism to inhibit the fuzing system from firing, the Initiation Inhibit contact is included in the interface. This interface does not affect the arming process, and should not be confused

45、with a disarm/rearm function, which uses the digital interface.3.4.5 Target Detection Device Signal and ReturnAlthough many fuzing systems can be expected to employ an internal Target Detection Device (TDD, typically an impact sensor), sensors external to the fuzing system main housing may also be u

46、sed. These can provide for example a more rapid response to impact, detect proximity to the target, or detect other parameters associated with the weapon function, such as water depth.The Target Detection Device (TDD) Signal allows such sensors to send a trigger signal to the fuzing system when they

47、 sense the appropriate environment or target. The selection of “internal” (to the fuzing system main housing) or “external” is indicated to the fuzing system using data bits B3|B2 of byte 0 of Fuzing Mode 2, contained with the Mission Store Control Message sent from the aircraft to the weapon and tr

48、ansferred to the fuzing system through the Fuzing System Serial Data Interface as part of the “M” Command Data message.3.4.6 Post Release Environment Sensor Signal and ReturnClass 3, subclass A and subclass AD interfaces contain two connections, Post Release Environment Sensor (PRES) Signal and PRES

49、 Signal Return to enable the fuzing system to directly monitor and evaluate the analog signal derived by the sensor within the PRES. In order to permit monitoring of analog signals from sensors in current use, e.g., current air speed sensors, the PRES Signal and Return lines and fuzing system circuits must be able to handle or at least withstand up to 300 V.3.4.7 Address Bit DiscretesWhilst many weapons use only a single warhead wi