1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2009 SAE International All rights reserved. No part of this publication m
3、ay be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA)
4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AIR5654 AEROSPACE INFORMATION REPORT AIR5654 Issued 2009-04 IEEE-1394b for Military and Aerospac
5、e Vehicles Applications Handbook RATIONALE The rationale for this IEEE-1394b Applications Handbook is to provide application details, including explanations of AS5643, AS5643-based system design considerations, bus timing and scheduling, experiences on design tools, and lessons learned, that are not
6、 typically included in a SAE standard such as AS5643. It is intended to promote and support the use of SAE AS5643, and to serve as a platform for information exchange. SAE AIR5654 Page 2 of 82 TABLE OF CONTENTS LIST OF FIGURES 4 LIST OF TABLES 5 1. SCOPE 6 1.1 Purpose . 6 1.2 Background . 6 2. REFER
7、ENCE PUBLICATIONS 7 2.1 SAE Publications . 7 2.2 IEEE Publications 7 2.3 Other Publications . 7 3. DEFINITIONS OF TERMS AND ACRONYMS . 8 4. IN-DEPTH VIEW OF THE STANDARD 11 4.1 Introduction to SAE AS5643 Network Architecture and Protocols . 11 4.2 Highlights of SAE AS5643 Determinism and Fault Toler
8、ance 13 4.2.1 Determinism 13 4.2.2 System Integrity and Fault Tolerance Mechanisms 14 4.2.2.1 Enhanced Fault-Containment Schemes . 14 4.2.2.2 Enhanced Fault Isolation and Recovery . 15 4.2.2.3 Fault Protection by System-Level Redundancy 15 4.2.3 Failure Mode Analysis for SAE AS5643 Architecture . 16
9、 4.2.4 Failure Modes and AS5643 Solutions 16 4.2.5 FMEA Scoring . 19 4.3 Summary . 21 4.3.1 Evaluation for Applications Other Than Military Applications . 21 4.3.2 Enhancing Fault Containment, Fault Isolation and Recovery . 21 5. CONTROL COMPUTER DESIGN 22 5.1 Number of Ports per Node 22 5.2 Control
10、 Computer Synchronization . 23 5.3 Simultaneous Operation of Multiple Buses . 23 5.4 Buffer-Fill and Packet-Per-Buffer Modes 24 6. REMOTE NODE DESIGN 25 6.1 Number of Connected Ports Considerations 25 6.2 Redundancy Considerations . 25 6.2.1 System Integrity Management 25 6.2.1.1 Simplex System Inte
11、grity Management 25 6.2.1.2 Redundant System Integrity Management . 26 6.2.1.2.1 STOF Criteria (Condition 1) 26 6.2.1.2.2 Network Bus Mode (Condition 2) 26 6.2.1.2.3 CC Status (Condition 3) 26 6.2.1.2.4 Bus Mode (Condition 4) 27 6.2.1.2.5 Receive Valid Message (Condition 5) . 28 6.3 Bandwidth and Th
12、roughput Considerations 28 6.3.1 Application Scheduling of 1394 Transmit Packets . 28 6.4 Remote Terminal Design Lessons Learned . 28 6.4.1 STOF Synchronization 28 6.4.2 Peak Load Handling 28 6.4.3 Payload Path Integrity . 29 6.4.4 Failure Containment 29 6.4.4.1 Babbling Idiot Syndrome . 29 6.4.5 Mi
13、nimization of 1394 Bus Resets 29 7. FAULT TOLERANT NETWORK ARCHITECTURE AND TECHNIQUES 30 7.1 Architectural Considerations . 30 7.1.1 Redundant CCs. 30 7.1.2 Cross-Channeling CCs and Remote Nodes . 30 7.1.3 Looping Busses. 32 7.1.4 Leaf Nodes 33 7.1.5 Other Redundant Architecture Example . 34 7.1.6
14、Put All Pieces Together-The Network . 34 SAE AIR5654 Page 3 of 82 7.2 Physical Network Layout Considerations . 36 7.2.1 Distance Between Nodes 36 7.2.2 Repeaters 36 7.2.3 Overall Considerations 37 8. TEST EQUIPMENT CONSIDERATIONS AND SUGGESTION . 38 8.1 Bus Analyzer Requirements . 38 8.2 Signal Inte
15、grity Requirements . 41 8.2.1 Signal Integrity Test Tool Requirements . 42 9. BUS TIMING AND LATENCY . 44 9.1 Establishing STOF Frequency 44 9.2 Establishing STOF Offsets For Each Node 45 9.3 Establishing the Process for Changing STOF Offsets 47 10. CABLE DESIGN 48 10.1 Extended Cable Length 48 10.2
16、 Harness Considerations For SAE Standard AS5643/1 49 10.2.1 Harness Construction . 50 10.2.2 Testing of Harnesses 52 10.2.2.1 Testing of Harnesses Before Installation 52 10.2.2.1.1 Bit Error Rate Script 54 10.2.2.2 Testing of Harnesses After Installation . 60 11. LESSONS LEARNED IN SYSTEM INTEGRATIO
17、N . 61 11.1 Techniques for Mitigating Failures 61 11.1.1 Identifying/Avoiding Single Point Failures . 61 11.1.1.1 Power Sources of Redundant Nodes on Different Buses . 61 11.1.1.2 Clock Sources . 62 11.1.2 Hardware Failures That Lead To Bus Resets 62 11.1.2.1 Intermittent Electrical Connection . 64
18、11.1.2.2 Marginal Signal Quality . 64 11.1.2.3 ”Loping” Power Supplies . 65 11.1.2.4 Events At The Circuit Board Level 65 11.1.3 Handling Initialization Sequences and Bus Resets 65 11.1.3.1 Handling Bursts of Resets 66 11.1.3.2 Bus Reset Script . 66 11.1.3.3 Preventing LRUs From Generating Bus Reset
19、s . 68 11.1.4 Packet Data Structures . 69 11.1.4.1 Software Interface Development (i.e. packet definitions) . 69 11.2 Considerations for Testing and Optimizing the System 69 11.2.1 Internal STOF Consideration 69 11.2.2 Device Settings for Optimal Throughputs . 70 11.2.3 Bit Error Rate Verification .
20、 71 11.2.4 Suggestion for Robust Configuration 72 11.2.5 ASM Payload Size Clarification 72 11.2.6 Forced Root Node Setting 72 12. FREQUENTLY ASKED QUESTIONS AND ANSWERS 73 13. NOTES 82 SAE AIR5654 Page 4 of 82 LIST OF FIGURES Figure 1 Basic network with single CC. 11 Figure 2 Basic network with sing
21、le CC and a loop. 12 Figure 3 Representative triplex CC architecture. 13 Figure 4 Representative triplex CC architecture. 22 Figure 5 Multiple 1394 buses with Dedicated Local Memory 23 Figure 6 Multiple 1394 buses competing for common memory . 24 Figure 7 Flowchart of Redundant System Integrity Mana
22、gement . 27 Figure 8 Triplex network with multiple cross-channel connections. . 31 Figure 9 Basic network with single CC and a loop. 32 Figure 10 Four nodes cross-connected to each other. . 34 Figure 11 Representative triplex CC architecture. 35 Figure 12 Repeater. 37 Figure 13 Cable Testing using a
23、 Triple FireSpy 1394 Bus Analyzer and Repeaters 40 Figure 14 Cable Testing using a QP-ICT Interconnect Tester with output level control 41 Figure 15 Example 38999 Test Fixture . 42 Figure 16 QP-SQT Beta Signal Quality Tester . 43 Figure 17 Timing diagram for node A with STOF. 44 Figure 18 STOF offse
24、t effect on command path latency. . 45 Figure 19 Data latency timeline. . 46 Figure 20 Example sensed AOA to actuator motion. 47 Figure 21 Example Cable Termination Method from AS5643/1. 50 Figure 22 Improved Cable Termination Method. 51 Figure 23 Eye pattern measurement. . 53 Figure 24 Harness test
25、 set-up. 54 Figure 25 Bit error rate GUI. . 59 Figure 26 Harness with excessive right-angle bends . 60 Figure 27 Basic network with single CC and a loop. 62 Figure 28 Initialization and configuration timing. . 63 Figure 29 Typical Disconnect and Reconnect Timing 64 Figure 30 Bus reset generation GUI
26、. 68 Figure 31 Host interfacing with network logic. 70 Figure 32 BER test setup. . 71 Figure 33 Test times for various confidence levels and bit errors. . 72 Figure 34 The displacement of asynchronous stream packets with isochronous packets. . 81 SAE AIR5654 Page 5 of 82 LIST OF TABLES Table 1 Failu
27、re Modes Analysis .17 Table 2 FMEA score results .20 Table 3 Guidance for external cable length .49 SAE AIR5654 Page 6 of 82 1. SCOPE This handbook is intended to accompany or incorporate AS5643 IEEE-1394b Interface Requirements for Military and Aerospace Vehicle Applications, AS5643/1 S400 Copper M
28、edia Interface Characteristics over Extended Distances, AS5657 Test Plan/Procedure for AS5643 IEEE-1394b Interface Requirements for Military and Aerospace Vehicle Applications, AS5706 Test Plan/procedure for AS5643/1 S400 Copper Media Interface Characteristics Over Extended Distances, and ARD5708 Fr
29、equently Asked Questions about IEEE-1394b and SAE AS5643. In addition, full understanding of this handbook also requires knowledge of IEEE-1394-1995, IEEE-1394a and IEEE-1394b standards. This handbook contains detailed explanations and architecture analysis on AS5643, bus timing and scheduling consi
30、derations, system redundancy design considerations, suggestions on AS5643-based system configurations, cable selection guidance, and lessons learned on failure modes. 1.1 Purpose The purpose of this document is to provide application details, including explanations of AS5643, AS5643-based system des
31、ign considerations, bus timing and scheduling, experiences on design tools, and lessons learned, that are not typically included in a SAE standard such as AS5643. It is intended to promote and support the use of SAE AS5643, and to serve as a platform for information exchange. 1.2 Background IEEE-139
32、4 was invented by Apple Computer in the 1980s and is also known as Firewire. In 1995 the IEEE adopted it and created a specification to support its use. That specification has been continuously upgraded and improved. In 2002, the IEEE released 1394b, the version SAE has adopted for use in military a
33、nd aerospace vehicles. IEEE-1394-2008 which combines all of the previous versions and errata into a single document was released June 2008. Answers to Q1 and Q3 in Section 12 Frequently Asked Questions will provide more details on different versions of IEEE 1394 standards. Prior to its use in the Lo
34、ckheed Martin F35 Lightning II (Joint Strike Fighter), IEEE-1394b had never been used as a flight critical or mission critical system data bus in any military or aerospace vehicle. The IEEE-1394b specification does not provide necessary functionalities such as guaranteed determinism and information
35、integrity for use in aerospace applications such as the flight control system for aircraft. For that reason, the SAE variant of IEEE-1394b was conceived and implemented. In addition to the F-35 program, the use of IEEE-1394b for safety critical/mission critical systems has been considered or is bein
36、g considered by other major commercial aircraft program, space manned and unmanned vehicles for explorations, and defense systems other than fighters. SAE AIR5654 Page 7 of 82 2. REFERENCE PUBLICATIONS The following publications for a part of this document to the extent specified herein. The latest
37、issue of SAE publications shall apply. The applicable issue of the other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this do
38、cument, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. D
39、oc No. Date/Rev Title N/A 7thRevision - Approved May 14, 2004 SAE International Technical Standards Board Governance Policy N/A Revised February 2002 SAE Aerospace Council of the SAE Technical Standards Board Organization and Operating Guide for Aerospace Standards Development Program N/A October 20
40、04 SAE Aerospace Technical Report Style Manual AS5643A October 2006/A IEEE-1394b Interface Requirements for Military and Aerospace Vehicle Applications AS5643/1 December 2004 S400 Copper Media Interface Characteristics Over Extended Distances AS5657 February 2007 Test Plan/Procedure for AS5643 IEEE-
41、1394b Interface Requirements for Military and Aerospace Vehicle Applications AS5706 May 2007 Test Plan/Procedure for AS5643/1 S400 Copper Media Interface Characteristics Over Extended Distances ARD5708 March 2007 Frequently Asked Questions About IEEE-1394b and SAE AS5643 2.2 IEEE Publications Availa
42、ble from Institute of Electrical and Electronics Engineers, 445 Hoes Lane, Piscataway, NJ 08854-4141, Tel: 732-981-0060, www.ieee.org. Doc No. Date Title IEEE Std 1394-1995 1995 IEEE Standard for a High Performance Serial Bus IEEE Std 1394a-2000 2000 IEEE Standard for a High Performance Serial Bus-A
43、mendment 1 IEEE Std 1394b-2002 2002 IEEE Standard for a High Performance Serial Bus-Amendment 2 IEEE Std 1212-2001 2001 IEEE Standard for a Control and Status Registers (CSR) Architecture for Microcomputer Buses IEEE Std 1394-2008 2008 IEEE Standard for a High Performance Serial Bus 2.3 Other Public
44、ations Doc No. Date/Rev Title N/A January, 2000, 1.1 1394 Open Host Controller Interface Specification SAE AIR5654 Page 8 of 82 3. DEFINITIONS OF TERMS AND ACRONYMS The reader is encouraged to review the following terms and definitions before proceeding to the remainder of the document. By conventio
45、n, these terms are expanded here only; in the remainder of this document, these terms are used in their shortened form. Term Definition ADS Air Data System senses, computes and outputs all parameters associated with aircraft movement through the atmosphere. AOA Angle of Attack is a term used in aero
46、dynamics to describe the angle between the airfoils chord line and the direction of airflow wind, effectively the direction in which the aircraft is currently moving. It can be described as the angle between where the wing is pointing and where it is going. ASM Anonymous Subscriber Messaging is tail
47、ored to support deterministic, secure, low-latency communication between processors, sensors, instrumentation, and displays in mission-critical applications. It uses Message IDs to decouple the network traffic from physical addresses so application software can communicate without knowledge of netwo
48、rk topology. AWG American Wire Gauge, also known as the “Brown and Sharpe“ wire gauge, is used in the United States and other countries as a standard method of denoting wire diameter, especially for nonferrous, electrically conducting wire. BER Bit Error Rate is a parameter relating to the quality o
49、f a serial transmission system. BER is the percentage of bits having errors, relative to the total number of bits received in a transmission. BER is usually expressed as ten to a negative power. Burstability The ability to support burst-mode in which a device is transmitting data repeatedly without waiting for input from ano
