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
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4、0 (outside USA) 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/AIR6552/3 AEROSPACE INFORMATION REPORT AIR6552/3 Issued 2016-05 Network End-to-En
5、d Data Link Evaluation System Transceiver Health Monitoring RATIONALE To assure mission readiness there is a need for a robust optical performance monitoring system capable of detecting, localizing, and isolating impairments as well as assisting in failure prediction of the physical layer of a fiber
6、 optic network. Transceiver health monitoring can provide real-time information about the physical, electrical, and optical characteristics. TABLE OF CONTENTS 1. SCOPE 3 2. REFERENCES 3 2.1 Applicable Documents 3 2.1.1 SAE Publications . 3 2.2 Related Publications . 3 2.2.1 SAE Publications . 3 2.2.
7、2 ANSI Accredited Publications . 3 2.2.3 IEC Publications 4 2.2.4 NASA Publications 4 2.2.5 NAVAIR Publications 4 2.2.6 U.S. Government Publications 4 2.2.7 ARINC Publications . 4 2.2.8 Small Form Factor (SFF) Committee 4 2.2.9 Other References 5 3. MEASUREMENT OF TEST DATA . 5 3.1 I2C . 5 3.2 Compu
8、ter Access 5 3.3 Local CPU . 6 4. STORAGE OF TEST DATA 6 4.1 Local I2C Non-Volatile Memory . 6 4.2 Format of Test Data 6 4.2.1 AS8472 and Derivatives 6 SAE INTERNATIONAL AIR6552/3 Page 2 of 105. ACCESS TO TEST DATA. 85.1 Methods to Access Test Data in Local Memory within Enclosure 95.1.1 No Connecti
9、on 95.1.2 Dedicated Link to Connector through Enclosure Wall 95.1.3 Wireless Link that Requires No Direct Connection. 95.1.4 Transporting kbps Data on Gbps Fiber Optic Links without Interfering or Affecting Performance. 9FIGURE 1 CPU I2C MASTER READS PERFORMANCE DATA FROM TRANSCEIVER. 6FIGURE 2 CPU
10、I2C MASTER READS PERFORMANCE DATA FROM TRANSCEIVER AND STORES IT IN NON-VOLATILE MEMORY 6FIGURE 3 USE OF IEEE 1902.1 NODE FOR DATA ACCESS. 9FIGURE 4 LOW MODULATION DEPTH KBPS DATA ON EXISTING FIBER OPTIC LINKS. 10FIGURE 5 CIRCUIT SCHEMATICS FOR LOW SPEED LOW MODULATION DEPTH DATA TRANSMISSION AND RE
11、CEPTION. 10TABLE 1 A/D VALUES AND STATUS BITS (2 WIRE ADDRESS A2H) 7TABLE 2 MODULE MONITORING VALUES . 7TABLE 3 CHANNEL MONITORING VALUES for a FOUR CHANNEL TRANSCEIVER. 8TABLE 4 CHANNEL MONITORING VALUES FOR A TWELVE CHANNEL TRANSCEIVER 8SAE INTERNATIONAL AIR6552/3 Page 3 of 101. SCOPEThis document
12、 establishes methods to obtain, store, and access data about the health of a fiber optic network using commercial sensors located in or near the transceiver. This document is intended for: Managers, Engineers, Contracting Officers, Third Party Maintenance Agencies, and Quality Assurance.2. REFERENCE
13、SThe documents listed in 2.1 are referenced in this document. The documents listed in 2.2 are provided for information purposes only and do not form a part of the requirements of this document.Applicable DocumentsThe following publications form a part of this document to the extent specified herein.
14、 The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In theevent of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in
15、this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.SAE PublicationsAvailable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.or
16、g.AS8472 Specification for Diagnostic Monitoring Interface for Optical TransceiversRelated PublicationsThe following documents are provided for reference only and do not form requirements for this specification.SAE PublicationsAvailable from SAE International, 400 Commonwealth Drive, Warrendale, PA
17、15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org.AIR6031 Fiber Optic CleaningARP5602 A Guideline for Aerospace Platform Fiber Optic Training and Awareness EducationAS5675 Characterization and Requirements for New Aerospace Fiber Optic Cable Assembli
18、es - Jumpers, End Face Geometry, Link Loss Measurement, and InspectionARP5061 Guidelines for Testing and Support of Aerospace, Fiber Optic, Inter-Connect SystemsANSI Accredited PublicationsCopies of these documents are available online at http:/webstore.ansi.org.ANSI Z136.1-2007 American National St
19、andard for Safe Use of LasersANSI/TIA-440-B-2004 Fiber Optic TerminologySAE INTERNATIONAL AIR6552/3 Page 4 of 10IEC PublicationsAvailable from IEC Central Office, 3, rue de Varembe, P.O. Box 131, CH-1211 Geneva 20, Switzerland, Tel: +41 22 919 02 11, www.iec.ch.IEC 60825-1 Laser Safety Equipment Cla
20、ssification (Safety of laser products)IEC 60825-2 Safety of Optical Fiber Communication SystemsIEC 60825-4 Laser GuardsNASA PublicationsAvailable from NASA, Documentation, Marshall Space Flight Center, AL 35812, www.nas.nasa.gov.NASA-STD-8739.5 Fiber Optic Terminations, Cable Assemblies, and Install
21、ationNAVAIR PublicationsAvailable from Commanding Officer, Naval Air Technical Data and Engineering Service Command, Naval Air Station, North Island, P.O. Box 357031, Building 90, Distribution, San Diego, CA 92135-7031.NAVAIR 01-1A-505.4 Installation and Testing Practices Aircraft Fiber Optic Cablin
22、gU.S. Government PublicationsCopies of these documents are available online at http:/quicksearch.dla.mil.FED-STD-1037 Glossary of Telecommunications TermsMIL-STD-1678 Fiber Optic Cabling Systems Requirements and MeasurementsARINC PublicationsAvailable from ARINC, 2551 Riva Road, Annapolis, MD 21401-
23、7435, Tel: 410-266-4000, .ARINC Report 805 Fiber Optic Test ProceduresARINC Report 806 Fiber Optic Installation and MaintenanceARINC Report 807 Fiber Optic Training RequirementsARINC Specification 600-19 Air Transport Avionics Equipment InterfacesSmall Form Factor (SFF) CommitteeSFF specifications a
24、re available at ftp:/ Diagnostic Monitoring Interface for Optical TransceiversSFF-8053 Gigabit Interface Converter (GBIC)INF-8074 Small Form Factor Pluggable (SFP) TransceiverSAE INTERNATIONAL AIR6552/3 Page 5 of 10SFF-8079 SFP Rate and Application SelectionSFF-8089 SFP Rate and Application ValuesOt
25、her ReferencesFiber Optics Installer (FOI) Certification Exam Guide, Bill Woodward, ISBN 978-1-119-01150-7Cabling Part 2: Fiber-Optic Cabling and Components, 5th , Bill Woodward, ISBN: 978-1-118-80748-4Understanding Fiber Optics, 5th Edition, Jeff Hecht, ISBN 0-13-117429-03. MEASUREMENT OF TEST DATA
26、Commercial fiber optic transceivers that have built-in-test (BIT) capabilites support Digital Diagnostics Monitoring (DDM) functions according to the industry-standard AS8472, which is derived from SFF-8472. This document specifies communications via an inter-integrated circuit (I2C) link to access
27、many memory locations. Most of these locations contain information that describes the manufacture and capabilities of the transceiver, as well as areas of alarm and warning flags. Five locations contain data that describe the operational performance of the transceiver in various optional formats. Of
28、 primary interest are ten bytes that periodically provide internal measurements of:xModule temperaturexSupply voltagexTransmitter laser bias currentxTransmitter output powerxReceiver input signal power levelOther possible test/alarm points may be:xPossible original test data from manufacturerxBaseli
29、ne OTDR map of linkxNew map and compare function for fault detectionxFault/ alarm flags in I2CI2CIt is most likely that all future transceivers will continue to use the I2C bus to access their test data memory registers. Computer AccessAn external computer accesses these memory locations via the I2C
30、 link which consists of one bi-directional data line and one clock line as well as a return. The I2C bus specification describes the use of this bus. SAE INTERNATIONAL AIR6552/3 Page 6 of 10Local CPUIt is very unlikely at present that any existing central processing unit (CPU) such as a flight contr
31、ol computer or a missioncomputer will serve to access such an I2C link. Each package or board will most likely contain a very low performance CPU with an I2C port to access transceivers in the package or on the board. This local CPU will convey the data elsewhere via some data link or will store the
32、 data locally in a suitable memory. Figure 1 shows a CPU with an I2C port. FIGURE 1 - CPU I2C MASTER READS PERFORMANCE DATA FROM TRANSCEIVER4. STORAGE OF TEST DATAIf the CPU that reads the transceiver performance data cannot transfer it to another processor, it is recommended that data is stored loc
33、ally in a suitable memory.Local I2C Non-Volatile MemoryFigure 2 shows a non-volatile memory with an I2C port that the local CPU addresses and communicates with, serially, just as it communicates to the transceiver. With such an arrangement, the data remains secure until the local CPU or another devi
34、ce overwrites it via the same I2C interface.FIGURE 2 - CPU I2C MASTER READS PERFORMANCE DATA FROM TRANSCEIVER AND STORES IT IN NON-VOLATILE MEMORYFormat of Test Data The format of test data within the transceiver memory spaces is per AS8472 and its derivitives for newer transceivers with multiple ch
35、annels. AS8472 and Derivatives AS8472 serves as an example source of prognostic and diagnostic data that would be useful and it is not exalted above any other except that it is widely available and ready. What is common is the I2C interface and the need to distribute data.AS8472 provides real-time d
36、iagnostic data memory registers in address space A2 (hexadecimal) at bytes 96 to 109 (decimal) as shown in Table 1.Transceiver Clock Data 24LC256Serial I2CEEPROMCPUwithI2CTransceiver Clock Data CPUwithI2CSAE INTERNATIONAL AIR6552/3 Page 7 of 10TABLE 1 - A/D VALUES AND STATUS BITS (2 WIRE ADDRESS A2H
37、)Byte Bit Name DescriptionConverted analog values. Calibrated 16 bit data.96 All Temperature MSB Internally measured module temperature.97 All Temperature LSB98 All Vcc MSB Internally measured supply voltage in transceiver.99 All Vcc LSB100 All TX Bias MSB Internally measured TX Bias Current.101 All
38、 TX Bias LSB102 All TX Power MSB Measured TX output power.103 All TX Power LSB104 All RX Power MSB Measured RX input power.105 All RX Power LSB106-109 All Unallocated Reserved for future diagnostic definitions.Derivatives for multi-channel transmitters and receivers will have similar interfaces and
39、data groupings. These particular diagnostics are less useful than those shown in Table 1, as they only measure transmit bias current and not transmit power.Module monitoring values are shown in Table 2. Tables 3 and 4 show examples for four and twelve channel monitoring.TABLE 2 - MODULE MONITORING V
40、ALUESByte Bit Name Description22 All Temperature MSB Internally measured module temperature.23 All Temperature LSB24-25 All Reserved26 All Supply Voltage LSB Internally measured module supply voltage.27 All Supply Voltage MSB28-33 All ReservedSAE INTERNATIONAL AIR6552/3 Page 8 of 10TABLE 3 - CHANNEL
41、 MONITORING VALUES for a FOUR CHANNEL TRANSCEIVERByte Bit Name Description34 All Rx1 Power MSB Internally measured Rx input power, channel 1.35 All Rx1 Power LSB36 All Rx2 Power MSB Internally measured Rx input power, channel 2.37 All Rx2 Power LSB38 All Rx3 Power MSB Internally measured Rx input po
42、wer, channel 3.39 All Rx3 Power LSB40 All Rx4 Power MSB Internally measured Rx input power, channel 4.41 All Rx4 Power LSB42 All Tx1 Bias MSB Internally measured Tx bias, channel 1.43 All Tx1 Bias LSB44 All Tx2 Bias MSB Internally measured Tx bias, channel 2.45 All Tx2 Bias LSB46 All Tx3 Bias MSB In
43、ternally measured Tx bias, channel 3.47 All Tx3 Bias LSB48 All Tx4 Bias MSB Internally measured Tx bias, channel 4.49 All Tx4 Bias LSB50-57 All Reserved channel monitor set 3.58-65 All Reserved channel monitor set 4.66-73 All Reserved channel monitor set 5.74-81 All Reserved channel monitor set 6.TA
44、BLE 4 - CHANNEL MONITORING VALUES FOR A TWELVE CHANNEL TRANSCEIVERByte Bit Name Description34-57EvenAll Rx1 Power MSB Internally measured Rx input power, channel 1-12.34-57OddAll Rx1 Power LSB58-81EvenAll Tx1 Bias MSB Internally measured Tx bias, channel 1-12.58-81OddAll Tx1 Bias LSB5. ACCESS TO TES
45、T DATAThe primary challenge is to access the data within the box.With no access, the measurement data within the memory storage will only be available to a technician who opens the box for service after removal and return to a depot.With limited local memory, a flight-recorder type of storage can be
46、 used where recent values are stored sequentially in a rotary buffer until the memory is full. Storage pointer is then reset at the beginning and the oldest data are overwritten. During maintenance or repair, the latest data is then available for diagnostic.Also with limited local memory, accumulati
47、ve statistics may be used, i.e., histogram.Access to memory with a direct connection by ground service personnel in situ requires the addition of a new connector to the box. This may be allowable. There must be room for the connector on the box wall.Access to memory without direct connections is pos
48、sible via IEEE 1902.1 magnetic loop wireless, IEEE 802.15.4g wireless, or another recognized standard method.SAE INTERNATIONAL AIR6552/3 Page 9 of 10It may be acceptable to transport kilobit per second data in the background using gigabit per second fiber optic links on a non-interfering basis.Any a
49、pproach that communicates performance data between boxes with fiber transceivers that incorporate digital monitoring enables us to develop a distributed vehicle health monitoring system for the fiber network and perhaps other sensors.Methods to Access Test Data in Local Memory within Enclosure We look at some possible approaches in detail.No ConnectionWith no connection out of the bo
