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1、AEROSPACE STANDARD AS4117 Issued 1991-03 TEST PLAN FOR THE DIGITAL TIME DIVISION COMMAND/RESPONSE MULTIPLEX DATA BUS COUPLERS, TERMINATORS, AND DATA BUS CABLES FOREWORD This test plan consists of three major sections. The first deals with testing data bus couplers, a second with testing data bus ter
2、minators, and a third section with testing of the data bus cable. TABLE OF CONTENTS 1.SCOPE3 1.1General3 1.2Application.3 2.APPLICABLE DOCUMENTS 4 2.1 Military Publications.4 2.2Definitions4 2.2.1Bus Connection(s).4 2.2.2Stub Connection(s)4 2.2.3Terminators .4 2.2.4Shield.4 2.2.5Data Bus Coupler 6 2
3、.2.6Data Bus Cable .6 2.2.7zo.6 2.2.8Cable Attenuation6 3.ELECTRICAL TESTS6 3.1Data Bus Couplers 6 3.1.1Static Continuity Tests.6 Reaffirmed 2006-06 RATIONALE This document has been reaffirmed to comply with the SAE 5-year Review policy. SAE Technical Standards Board Rules provide that: “This report
4、 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 therefrom, is the sole responsibility of the user.” SAE reviews each
5、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 2006 SAE International All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, i
6、n 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) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS
7、: http:/www.sae.org -,-,- SAEAS4117 - 2 - TABLE OF CONTENTS (Continued) 3.1.2Dielectric Withstanding Voltage.9 3.1.3Insulation Resistance9 3.1.4MIL-STD-1553B Tests.10 3.1.5Dynamic Electrical Tests.13 3.2Data Bus Terminators .16 3.2.1Resistance Value 16 3.2.2Dielectric Withstanding Voltage.16 3.2.3In
8、sulation Resistance17 3.3Data Bus Cable.17 3.3.1Continuity 17 3.3.2Conductor DC Resistance.17 3.3.3Dielectric Withstanding Voltage.17 3.3.4Insulation Resistance18 3.3.5Shield Coverage18 3.3.6Attenuation19 3.3.7Capacitance (Mutual)19 3.3.8Capacitance Unbalance21 3.3.9Characteristic Impedance21 3.3.10
9、Cable Layup22 4.NOTES22 4.1Key Words.22 FIGURE 1Data Bus Couplers5 FIGURE 1A Transformer Data Bus Coupler5 FIGURE 1BDirect Data Bus Coupler5 FIGURE 2Waveform Integrity Test Circuit.11 FIGURE 3Standard Input Waveform .11 FIGURE 4Output Waveform12 FIGURE 5Common Mode Rejection Test Circuit.14 FIGURE 6
10、Bus Voltage Test Circuit14 FIGURE 7Phasing and Amplitude Test Circuit16 FIGURE 8Data Bus Cable Attenuation Circuit.20 SAEAS4117 - 3 - 1.SCOPE: 1.1General: This test plan defines the requirements of data bus components which comply with the requirements of MIL-STD-1553B, Digital Time Division Command
11、/Response Multiplex Data Bus. 1.2Application: The requirements of the test plan shall apply to data bus components designed to meet MIL-STD-1553B, when invoked in a specification or a statement of work. The test plan may be used for both design verification and production testing of data bus compone
12、nts. This test plan addresses only the electrical characteristics of the data bus components. Differences between data bus systems will exist due to particular program requirements and designer options. The system designer and contractor must therefore allow for the effects of temperature, vibration
13、, sealing, EMI/EMP, and other environmental factors on data bus component characteristics. Consideration of these factors will improve the possibility that data bus components will operate properly when used in the intended environment. The pass/fail requirements of the test plan shall be met under
14、all system operating environments. The DC resistance criteria, however, are assumed to be measured at 25C and would have to be corrected for measurements made at another temperature. For the purposes of this test plan, it must be possible to identify all bus and stub connections, the selected bus ca
15、ble characteristic impedance, the transformer winding resistances, and the values of any series and terminating resistors used within the coupler. This information must be included in a supporting documentation package provided by the bus coupler or bus terminator manufacturer. Because transformer c
16、oupled data bus couplers may contain terminating resistors and/or have cables attached, it will not be possible to directly test the transformer and resistors in every case. In such cases the transformers and resistors shall be tested prior to assembly to verify they meet the requirements of MIL-STD
17、-1553B. Again, system designers must make allowances for the expected environment when testing those coupler components. -,-,- SAEAS4117 - 4 - 1.2(Continued): Both connectorized and nonconnectorized couplers and terminators can be tested using this plan, provided electrical contact can be made to al
18、l signal (high and low) and shield (ground) connections of the components. Multiple stub couplers are tested by repeating the tests contained herein for each individual stub. An adjustment to the test limits may be required. The adjustments are specified in the appropriate sections. The tests may be
19、 performed in any order unless otherwise specified. 2.APPLICABLE DOCUMENTS: 2.1Military Publications: Available from Commanding Officer, Naval Publications and Forms Center, 5801 Tabor Avenue, Philadelphia, PA 19120. 2.2Definitions: 2.2.1BUS CONNECTION(S):Connection(s) designated for attachment of t
20、he coupler to the bus cable. The test plan refers to them as bus in and bus out; each is functionally identical. Attachment may be in the form of connector(s) or cable leads. See Figure 1A or 1B. 2.2.2STUB CONNECTION(S):Connection(s) designated for attachment of the stub cable to the coupler. The ca
21、ble connection is made to a distinct transformer for a transformer coupled data bus coupler, while for a direct coupler, the connection is made directly to the bus. Attachment may be in the form of connector(s) or cable leads. See Figure 1A or 1B. 2.2.3TERMINATORS:The shielded resistor used to termi
22、nate the bus in its characteristic impedance (Zo). NOTE:The terminating resistor may be located inside the coupler. See Figure 1A or 1B. 2.2.4SHIELD:The metallic enclosure which surrounds the coupler or terminator or the metallic braid surrounding the data bus cable. See Figure 1A or 1B. MIL-STD-202
23、FTest Methods for Electronic and Electrical Component Parts MIL-STD-1553BInternal Time Division/Response Multiplex Data Bus, with Notice 2, 8 Sept. 1986 SAEAS4117 - 5 - SAEAS4117 - 6 - 2.2.5DATA BUS COUPLER:It is the electronic module where the connection(s) between the stub(s) and the data bus are
24、made. It consists of bus in and bus out connections and at least one stub connection. For transformer coupled applications, the stub connection is made using two isolation resistors and a coupling transformer per MIL-STD-1553B. A terminating resistor may be placed inside the coupler as shown in Figu
25、re 1A. For direct coupled applications, the coupler consists of a shield in which a connection is made between the proper bus in and bus out signal leads to the corresponding stub signal leads. See Figure 1B. NOTE:When an internal terminating resistor is used it is possible the coupler may have only
26、 one bus connection. There are two basic styles of data bus coupler, one which has connectors and one which has cables attached. The type which has connectors is referred to in the test plan as “connectorized“. The type with cables attached are referred to in the test plan as either in-line data bus
27、 couplers or cable-equipped data bus couplers. 2.2.6DATA BUS CABLE:Two twisted, shielded, and jacketed conductors. 2.2.7Zo:The characteristic impedance of the data bus cable, where Characteristic Impedance = Zo = (?L/Cm), with L = Inductance per Foot Cm = Mutual Capacitance per Foot 2.2.8CABLE ATTEN
28、UATION: Cable power loss per unit length at a specified frequency, e.g., (db/100 ft at 1 MHz). 3.ELECTRICAL TESTS: The following paragraphs define the configurations, pass/fail criteria, and general procedures for testing data bus couplers, terminators, and cables. 3.1Data Bus Couplers: The followin
29、g four continuity tests shall be performed before attempting any other tests defined in this section. 3.1.1Static Continuity Tests:The purpose of the following tests is to perform DC continuity and resistance measurements on the data bus couplers: 3.1.1.1Bus Continuity Test (Bus In to Bus Out):Measu
30、re the resistance R, between bus in high and bus out high, as defined in Figure 1A or 1B. The pass criteria for a coupler with connectors attached shall be: R = 0.050 maximum(Eq.1) SAEAS4117 - 7 - 3.1.1.1(Continued): If the coupler is equipped with cables instead of connectors, a correction factor s
31、hall be applied to the above limit. For this case the pass criteria shall be: where: the correction factor R, is determined by multiplying the total cable length in feet L, by the DC resistance Rdc, per 1000 ft of the cable and adding it to the limit calculated for R. This test shall be repeated for
32、 bus in low to bus out low. NOTE:This test is not applicable to couplers that have only a bus in connection and an Internal terminating resistor. 3.1.1.2Bus Continuity Test (Bus In High to Bus In Low): 3.1.1.2.1Couplers With No Terminating Resistor:Measure the resistance RB, between the high and low
33、 sides of either the bus in or bus out connections. The pass criteria shall be: where: Rw is the transformer bus winding resistance (assumed to be less than 5 ), Rs is the value of the bus isolation resistors, and N equals the number of stubs. The values for Rw and Rs are supplied by the manufacture
34、r. The pass/fail criteria applies to a specific coupler design and that the nominal value may change for different coupler types. In the case of direct couplers, there shall be no continuity between signal high and low when measured on either bus in or bus out. In cases where couplers have cable att
35、ached, the correction factor mentioned shall be required to allow for the additional resistance of the cable. The modified pass criteria for RB shall be: where as defined in Equation 3: R = (0.050 + R) maximum(Eq.2) R = 0.001 LRDC (Eq.3) RB = (Rw + 2Rs)/N) 3% (Eq.4) RB = (Rw + 2Rs)/N) 3%) + R (Eq.5)
36、 R = 0.001 LRDC (Eq.3) SAEAS4117 - 8 - 3.1.1.2.2Couplers With Internal Terminating Resistor:Measure the resistance RB, between the high and low sides of the bus connection. The pass criteria shall be: where: Rs, Rw, and N are defined as before and Rt is the value of the terminating resistor, which s
37、hall be supplied by the coupler manufacturer. This limit is for a specific coupler and will vary with the coupler design. NOTE:For direct couplers RB shall be equal to Rt. In cases where couplers have cable attached, the correction factor mentioned shall be required to allow for the additional resis
38、tance of the cable. As before in Equation 3, the adjustment R, is equal to: Therefore, the modified pass criteria for RB shall be: 3.1.1.3Stub Continuity: Measure the resistance Rst of the high to low side of the stub connection. The pass criteria shall be: When testing direct couplers without an in
39、ternal terminating resistor, the value measured at the stub connection should be greater than 1 M. If the direct coupler has an internal resistor Rt, the DC resistance value measured Rint shall be equal to: In transformer couplers, which have cables attached, the limits must be increased to reflect
40、the additional DC resistance. The adjustment is determined as was shown. That amount is then added to the limit of 5 for the transformer coupler or for a direct coupler the appropriate value of Rt. The pass criteria shall be: or in the case of a direct coupler with an internal resistor: RB = (2RS +
41、RW)Rt)/(2RS + RW + NRt) 3% (Eq.6) R = 0.001 LRDC (Eq.3) RB = (2RS + Rw)Rt)/(2RS + RW + NRt) 3%) + R (Eq.7) Rst = 5.0 maximum(Eq.8) Rint = Rt 3% (Eq.9) Rst = (5 + R) maximum(Eq.10) Rint = (Rt 3%) + R (Eq.11) -,-,- SAEAS4117 - 9 - 3.1.1.4Shield Continuity:The DC resistance Rshield of the shield throug
42、h the coupler shall be measured between each bus and stub shield connection point and the enclosure. For connectorized versions, the measurement points shall be the outer metal shell of the connector(s) and the mounting flange of the enclosure. The pass criteria shall be: For couplers with cable att
43、ached, the measurement points shall be between each cable braid. The Rshield limit must be modified by the correction factor R, where R is defined as before. The pass criteria shall be: 3.1.2Dielectric Withstanding Voltage:The purpose of this test is to verify that there is adequate isolation provid
44、ed between the shield and any signal lead. When measured in accordance with MIL-STD-202F, at 600 V rms minimum and 50/60 Hz, with the potential applied between each bus signal lead and the shield for 1 min, the coupler under test shall show no evidence of breakdown or arcing. The test shall be repea
45、ted with the potential applied between each stub signal lead and the shield. 3.1.3Insulation Resistance:This test is used to quantitatively measure the resistance offered by the insulating materials of the coupler to an impressed direct voltage, which will tend to produce a leakage current through o
46、r on the surface of those materials. 3.1.3.1Insulation Resistance (Signal Lead to Shield):When tested in accordance with MIL-STD-202F, at 250 V DC, with the potential applied between each bus signal lead and the shield, the coupler shall have an insulation resistance of 1000 M minimum. The test shal
47、l be repeated for each stub signal lead and the shield. 3.1.3.2Insulation Resistance (Bus to Stub):When tested in accordance with MIL-STD-202F, at 250 V DC, with the potential applied between each stub signal lead and a bus signal lead, the coupler shall have an insulation resistance of 1000 M minim
48、um. NOTE:This test is not applicable to direct couplers. If this test is applied to direct couplers, the couplers may be damaged. Rshield = 0.050 maximum(Eq.12) Rshield = (0.050 + R) maximum (Eq.13) -,-,- SAEAS4117 - 10 - 3.1.4MIL-STD-1553B Tests: 3.1.4.1Waveform Integrity:This test is performed to
49、verify that the data bus couplers meet the droop, overshoot, and ringing requirements of MIL-STD-1553B. NOTE:For multiple stub or cable-equipped couplers, the transformers and resistors must be certified to comply with the requirements of MIL-STD-1553B as individual components. A single stub coupler shall be tested using the configuration shown i