ARINC 429 User`s Manual
Contents
1. Time OctalDigits B Data Parity Msg Status Figure 10 The Column to Search Selection The Column to Search selection shows all of the columns generated by the ARINC 429 decoder L hnisss ARINC 429 Decoder Users Manual 10 Page The set of single arrow buttons allow moving from field to field with or without added condition The set of double arrow buttons jump to the beginning and end of the record The set of play stop buttons start stop scrolling from the current position The Use Value box allows a search by value on the selected columns The search criterion is context sensitive which is reflected by the type of value decimal hexadecimal text and float A separate document contains more details on the search and its behavior Lahniss ARINC 429 Decoder Users Manual 11 Page 3 The Decode Modes 3 1 The 8 24 bit Decode Mode The simplest of all modes 8bits 24bits displays the Label and the data field in hexadecimal Notes that nibbles are swapped since they are encoded LSN first AA LeCroy WRAAXI File Vertical Timebase Trigger Display Cursors Measure Math Analysis Utilities Help Label 260 Data 0x91 444a Time O Label ata P Msg Pad Status T 41 46 ms l 174 am 18 41 09 msi 2 24r 0x 247 19 40 73ms 2 260 i 260 20 40 36 msi 125 JA46 I 125 40 00 ms 150 2636 I 150 22 39 63 msi 14140 0467 ctef 140 50 0 nsidiv Stop 0 0 mi 250kK5 45 0 G6 s Edge Positive Decode Setup2. 3 21 2 Altitude Tt 9 Possense 3 Min Max Label_Discrete 22 Binary Figure 18 Combining 3 User Signals into single Label 212 Also note that if the USigDs are listed in increasing offset order in the file they will appear in that order both in the Decode Table and the Label annotation Leahniss ARINC 429 Decoder Users Manual 22 Page This is a second example of a combination of fields within a label Here Label 260 is interpreted as Date in this case November 22 2012 SD2 Yri 10 YE1 Mod 10 Mo 1 Dyes 10 Dy SSM MNormaloperation Label 260 Li YF 10 Yr hi ne Dy 1ODy 55M1 01 2 ee 1 1 1 2 fm Pio fay 6 Raw O JI Rawsa PlRaw 1 lRaw 1 fif Aaw 2 31 0 ai I a Figure 19 User defined interpretation of the Date Label 260 Label 260 Date 260 SDI 2 PosSen 1 Min Max Label_Discrete 8 Binary 260 Yr 4 PosSen 1 Min Max Label_ Discrete 10 BCD 4 260 10 Yr 4 PosSen 1 Min Max Label_ Discrete 14 BCD 4 260 Mo 4 PosSen 1 Min Max Label_ Discrete 18 BCD 4 260 10 Mo 1 PosSen 1 Min Max Label_ Discrete 22 BCD 1 260 Dy 4 PosSen 1 Min Max Label_ Discrete 23 BCD 4 260 10 Dy 2 PosSen 1 Min Max Label_ Discrete 27 BCD 2 260 SSM 2 PosSen 1 Min Max Label_Discrete 29 Enum NormalOperation NoComputedData FunctionalTest FailureWarning L hnisss ARINC 429 Decoder Users Manual 23 Page 4 3 5 Common Signals found in many Labels Some common
3. CSV contains 12 to 14 tokens separated by commas as follows Label EquipementID Name Units Min Max SigBits PosSense Resolution MinTransit MaxTransit i sLabelType1 i 2 Offset 3 Detai IsList Each USigD s element has the following syntactic rules Name of the field Type of contents Range Used by algorithm uate eimat E fs 3 Name tet eetet o a ums tet eetet e fr Binaryand BCD USD only Mint tee e me pe eet sisus wooo 1o i Maxtransit re Figure 14 Listing of all Fields of the USigD line with comments ULDF files support commented lines starting with as the normal C convention Comment can also be added at the end of the line but not in the middle of the token list L hniss ARINC 429 Decoder Users Manual 16 Page 4 1 4 Line Contents following ARINC 429 The structure of the line largely follows the ARINC 429 standards familiar to those working in the avionics domain Deviations and additions are listed below and all cases are explained with examples in this document 4 1 5 Deviations from ARINC 429 Token 2 Equipment ID is decimal rather than hexadecimal and is not used by the annotation algorithm This token can be used to document the USigD if desired Token 5 6 In the ARINC tables the min and max are merged in one column with several possible syntaxes in human language not readily parsable In ULDF min and max have dedicated columns therefore dedica
4. E E A T E E R O 18 4 3 1 Enumerated itype ror DISChEl SLAG NG serrera ar E EE AEE O E EE EEA E E EOE TTT E EEEE VE E O OEIT N EEEN EO OEO ROE 19 4 3 2 BCD SII tor Discrete LaNena A E ARA a E aE E A E E AEAEE A TS 20 4 3 3 Binan Signal Tor Discrete Lapels sisissireesiciraeei sates ce eE ennei Ci EE ree e EEN AEA EENEN ENEAN EANAN INEA NENES EAEAN EKEN AOAN CEA ENACO ENANTA ECEN AEE EEEN TEE 21 AA COmDINNE Senas mO DTe e SS en a RTE E E E T RE E 22 4 3 5 Common Signals Tounaa Mimany Labels eenpinnn E a dich asualediaaqedcevad eaten nossa EEE E 24 L hniss ARINC 429 Decoder Users Manual 1 Page List of Figures PIE FADS OVI FOr FRING 2 a E E E E E E E E E 3 Figure 2 ARINC 429 Search tab when Zoom is sourced on Decoded Trace csssecccessececcessccccesecccsuececcueccessusccecsueceeauaeceeseusecesauececeuaeceeceusecessueceesuneceesenceesansecetseneess 3 PSUS IEE e T A E E E A E E 4 Feure4 Measuring the sigma bitrate usine the TIME CUS O15 arcee te tecnsecataninesutasrns sata conaseiennnasate nba AA E E E E 4 Fere So he User Bened Talo AiG WES OTO e E A E E E E 6 Figure 6 The Filter Tab and its actions when using Only Show Listed Labels cccccccsssccccesseccceesececcunscceseusececseeceeeueceeeesecesaueceseuaeceeseusecessuecessuaecesseneeeessunecessuneess 7 eN E E E e E E E A EAE A EEEE A A E A N E E AE E E E E E E EE 8 rareo LOOKING at eevee 1 A e e E EE EEE E AE A A EE EE EAE E 8 Fieure 9 Rescuing a troubled Siena WIEN manual
5. MeasureiGraph Setup Basic User Defined Fitter Levels Close view Decode Source 1 Data Protocol O UE ARINC429 eee et L C O VIB wT qj Decode 2 Table Rows Bitrate pam Hex l 5 100 kbit s ESE Details Decode 3 Rog Action for decoder y eee ene eee Output File User Defined v L l Configure Export a Decode 4 T z Measure Search Table Table DecodeTabl Browse 182013 9 53 11 PM Figure 11 Signal decoded in the 8 24 bits mode This mode is very useful when starting the work to quickly verify that each Label indeed contains 32 bits For example in the image above it is immediately clear that the Label contains 8 bits and the Data 24 bits grouped in 6 BCD digits of 4 bits L hniss ARINC 429 Decoder Users Manual 12 Page 3 2 The 8 2 19 2 1 bit Decode mode The second hexadecimal mode 8 2 19 2 1 also decodes in hexadecimal but separates the SDI and SSM from the data bits The SDI and SSM fields can also be represented in the Symbolic Decode Mode with more flexibility AA LeCroy WR44Xi File YWertical Timebase Pi isplay Cursors Measure Math Analysis Utilities Help Label 260 Data Ox024451 Time SDI Data SSM Pa Msg Pad 41 46 ms 1000000 174 41 09 ms 2 1052000 J 247 19 40 73ms 2 1 Ox244514 260 J 40 36 msi 12 1 Uxd4ce14 0 125 Oo 150 0 140 1 40 00 mes 1 058 SC 4c 22 39 63 MS a 0xETE Decode Setup MeasuretGraph
6. improvements of this release L hniss ARINC 429 Decoder Users Manual 2 Page 2 The User Interface 2 1 Overview of the tabs offered by the ARINC Decoder The User Interface of the ARINC 429 Decoder consists of 4 Tabs under the Decoder Each one of the Tabs will be described in details in the following pages An additional Tab is located under the Zoom controls whenever a decoded Zoom is in use Decode Setup Basic User Detined Fitter View Decode Source 1 Data Protocol m Mi ARINC 429 Figure 1 Tabs overview for ARINC 429 J oom Muniz corn Figure 2 ARINC 429 Search tab when Zoom is sourced on Decoded Trace As in all most other decoders there is no strict order in which to visit the tabs except for setting the bitrate in the Basic tab Once the decoding is correct all the controls might be used in any order Experience shows that the usage modes are as diverse as the users The problem at hand usually dictates the usage and the course of action This document will attempt to convey usage hints in connection with the features described Also note that the common decode infrastructure such as the Configure Table and the Export Table buttons at the bottom of the Decode Setup Tab are documented in the Teledyne LeCroy Serial Data Manual L hniss ARINC 429 Decoder Users Manual 3 Page 2 2 The Basic Tab Basic User Defined Filter Levels Close 24 Viewing Bitrate Hex 2S kbit s oe De
7. pacity ce Ga anp vee Deasv toa nay E A E beacons daesaed E a 12 3 2 TO STF SMe ONE COC pcg cece ea eprsltns ch ee E E E E abd loveseat A E pin sane oe nea pew ana ae pore tease ennaane se 13 343 THe ymn ool DECE MOOR arana ane enone etree sere eee en ee ee ee eee err ee eee en ere eee eee ee ee eee ee eee ee eee ee eee eee 14 4 Appendix A Symbolic Decoding in More Details seisseen EE E EEES 15 4 1 Explanatonmol the User Label Definition File esirinnas aa aa ae a aa a aa aa aaie aoda 15 4 1 1 Terminology CONVENON seisseen rissin rr reni Pir Tn EEEIEE ENI EEEE EAEE EAA NEEE AEA ASE ES PEES OA AEE TE AIEEE A EE OE AEE EES AE A EE EEEO ER EA EA EEOAE EA 15 P TENO e E ei cep es ccc nan E kc oc apnea csc E E E E E E E E E sae san ce ea aap meemieaencanaeanees 15 4 1 3 NNT SV AN a toate cease A E ota aeei eae sete gaat owen ate O E R on cenesed accieee espe EA E setae cs soatecaeeieernsaaestoeaschusan E 16 4 1 4 Hne conte me ONE ARINC AA orie meaner ce Tne rs env Pr nner Tne AE nv ne ne E ren ne ae ee ny ee err ne men ee ren nee nC eee Cane ee Cee E E Serre eer Te 17 4 1 5 DEVONS COMM ARINC AA sich ara aA a a A A E E Sarectuar ua ecm ba aenvaivs Ga onarea Denia hed easy stacey A A T E A E T 17 4 1 6 Etenen UO ARINC A2 iie A E a E E E E A EE A E E E E E E E E E 17 4 1 7 Umeed TOREN ree A N AEE AA O A A A A E E A E E AA AE A A O EE E E E A EAE NE 17 4 2 Sea eeek eS SE A A A AE A E EE A A E A A nd N E E E A E A E E A T 17 4 3 Discrete l o geen er nnn ner A E T E
8. the levels do not cross the Baseline noise or the Plateau noise The following image will look at an example where the levels have to be tuned manually L hniss ARINC 429 Decoder Users Manual 8 Page Onginal Signal F1 h hT qi T i ir ny Aid Ls fida Dz at 0x Ac E zol h Fi Ad i att Pate Il dial RP L pur i A MUL yk de Figure 9 Rescuing a troubled Signal with manually tuned Levels This is a real world trace Signals can be noisy unbalanced or corrupted in many other ways In this case we would have to manually tune the levels to decode In some cases it is easier to use the Absolute level setting in Volts It is also possible to have one level in and the other one Absolute Click on the image This example shows 3 signals M2 F1 and F2 F1 and F2 are identical traces Both of them are based on M2 with the same Gaussian noise added If you look closely at the images you will see that F2 decodes correctly thanks to the manually tuned levels F1 is incorrect because the levels cross into the noise where indicated by the red violation circles Lahniss ARINC 429 Decoder Users Manual 9 Page 2 6 The Search Tab Column To Search OctalDigits LetRight Pad 100 Figure 10 The Search Tab when used on a Decoder The search tab is available when a Zoom is connected to a decoded Trace In this situation the normal Zoom controls are augmented by the Search Controls as show in the Figure above
9. ARINC 429 Decoder Users Manual January 2013 Contents DWC TO g E ecu cec enereaee usa E A A A EE A E E A E A EE E N A A A A AA P A crore enmmnen E T 2 2 TEU er 9 E ev E ne T T E A eer eee re 3 2 1 Overview of the tabs offered by the ARINC De COED cccccccsssseccccseeseececsaesececeeesseeeeeseeneeeesseeseeeeeeeeeeeeeeeeeeeesaeeseeeeeeeeeeeeeeaeeeeeeeeaeeeeeeesaaeseeeeeaeeeseeesaeasseceesaansseeessauaseeeesauaseeeesagasses 3 2 2 TE hl Wi secs E E ese schon pce ae in A A cease nrc t i eso ts ab eatin cuban eti sf og spent ses log bin enw oct avons eas ote etbvg ee enor eed 4 2 3 The User Defined Tab esc ete ects aaersec eas ea ease encase gape a vase cate ergacontess co re ates ane peta eancteneeae cares quanti tatevqen ate anmyqesea way cabs arnstea eopnaues ance acnescenu ssa nmenadsaneneen saeenenss sans eesabarereeaexaies aeaneacreeeaneunenearavenca 6 2 4 MPVS EST Ale e a E a S env ose ua uneeed sa0saecaqsairanecdeaenasecusvaneaueoreaceaeenesareooseaenuacarearese 7 2 5 TOC LENEI lf a nen Some ener erent Tener a emer me ene rinn E ener renee ree Caren meee n oe rer ae ner hone ree Sere eee err mrer Sener nt ere Teer eee eer E nee eee 8 2 6 TMS OUD Ai acer AE eae clas geen eres vance E yaw wot va na vag ei nee be ons va variance dine AS O I aan AE EET EE AE E A E E 10 VO CO eS sss ec nese A a epee beats seats ec pa oe cero ratio A T pcteo cian see A A pond veneers asae aeenceah ver ian as asieu AE T 12 3 1 ESAD SCO 1 ae sas ease E A e nie eran om
10. Sen 1 Min Max Label Discrete 12 Enum Prim Sec 273 IRSZF S Stat 1 PosSen 1 Min Max Label Discrete 13 Enum Present Wot Present 274 1F5 FHS Source 1 FosSen 1 Min Max Label Discrete 14 Enum Prim Sec 273 Hum Sat Yis 4 Posthen 1 Min Wax Label Discrete 15 Binary efa N4um Sat Used 4 PosSen 1 Min Maz Label _ Discrete 19 Binary 273 GLSSU Op Mode 5 PosSen 1 Min Max Label Discrete 23 Enum Self tst Init Acq Nav SBAS Nav SBAS PA Alt 4id Res Aided Fault 274 H5B Sat Used 1 PosSen 1 Min Wax Label Discrete 28 Enum lt 15 15 274 55M 2 PosSen 1 Min Max Label Discrete 29 Enum Norm Op HCD FunctionalTest FailureWarning Figure 13 Example of ULDF file with several USigD for Label 273 of a civilian GPS L hniss ARINC 429 Decoder Users Manual 14 Page 4 Appendix A Symbolic Decoding in More Details 4 1 Explanation of the User Label Definition File 4 1 1 Terminology Conventions 4 1 2 Terminology The file is called ULDF User Label Definition File It is expected that each Equipment for example a radio Altimeter or a GPS requires one ULDF Variations of the same Equipment manufactured over decades could also require different ULDF files to accommodate differences of precision Altitude precision to the meter or decimeter or additional Labels Support for GPS auxiliary results However there can be unused information in a ULDF file If a pie
11. Setup View Decode Source 1 Data Protocol ARINC 429 Table aan Bitrate 100 kbit s O BADA User Defined 8 24 F Output File D AD re 1812013 9 55 49 PM Figure 12 Signal decoded in the 8 2 19 2 1 bit mode L hnisss ARINC 429 Decoder Users Manual 13 Page 3 3 The Symbolic Decode Mode This mode is the richest of all the 3 modes and it is described in the following sections Unlike the simple modes it requires the user to provide a definition file containing the description of the signals emitted by the equipment When using the Symbolic mode also known as User Defined or User Interpreted the data field of each Label is decoded according to a file supplied by the user for its own system and equipment Each Label value is decoded independently The syntax of this file is described in detail in Appendix A Examples are also provided A text file drives the interpretation algorithm The following image gives a feeling for these files under a simple editor such as Notepad for MS Windows a cGPS_L101 102 110 111 260 273 txt Notepad _ S File Edit Format View Help Label 273 274 SD1I 2 PosSen 1 Min Max Label Discrete 8 Enum Hot Used Unitl Unit2 Unit3 G individual bits MSB Sat 1 FPosSen 1 Min Maz Label Discrete 10 Enum lt 15 VYis gt 15 Vis FMS DADS Stat 1 PosSen 1 HWin Maz Label Discrete 11 Enum Present Not Present FHS DADS Source 1 Pos
12. User Signals have been used for decades in many Labels In an attempt to ease the constitution of ULDF files we list some of the common ones with their screen renderings on an arbitrary signal These lines can therefore be cut and paste into any ULDF file USigD coding example Rendering on trace Comment The line can be cut and paste into the ULDF file The Source Destination ID SDl used in some 2 i labels can be coded as a binary Signal 212 SDI 2 1 Label_Discrete 8 Binary w Feb T O In this case the Unit s field is left blank 212 Sign 1 1 Label_ Discrete 28 Enum _ Sams The sign fields used by some labels in bit 29 LLL or 28 when 0 based can be coded as a 1 bit enumerated Signal 212 SSM 2 The SSM field for BCD data PosSen 1 Min Max Label_ Discrete 29 Enum NormalOperation NoCo th 0x00 MOrMal pera mputedData FunctionalTest FailureWarning Raw O L hniss ARINC 429 Decoder Users Manual 24 Page 212 SSM 2 The SSM field when used for BCD Latitude PosSen 1 Min Max Label_ Discrete 29 Enum North NoComputedDat N OFL a FunctionalTest South 212 SSM 2 The SSM field when used for BCD Distance PosSen 1 Min Max Label_ Discrete 29 Enum Right NoComputedData ot Right and Left FunctionalTest Left z 212 SSM 2 a The SSM field when used in conjunction with PosSen 1 Min Max Label_ Discrete 29 Enum FailureWarning NoCom FailurevYarni
13. Visual explanation of each relevant token Of AN binary TYP cccccesseccccessccccesececsesececcueecceseusececsusececsuneccesausecessuseceeeuneceesenecessuseceseunecessenecessunecetsenecetsegas 21 Figure 18 Combining 3 User Signals into single Label 212 cc cc ccccccccsssccccsssecccsesececceecceesesececsuseceeeeueccesansecesauneceeeeneceeeausecessuececeuneceesausecesaueceseunscesseneeessuecessunecessanas 22 Figure 19 User defined interpretation of the Date Label 260 00 ccccccssseccccesececceneccecaesececsesececcenecceseusecesausecesseeceeseesecessunecesseneceesenecessuneceseeneceesennceessuecetsunecessegas 23 Figure 20 Table showing commonly found signals cccccccssseccccsecccceneccccesecccauseccccueccecausecessuseceesunecceseusecessunecessuseceesensecesauneceseuneceesenecessusececsenecesseneeessuecetsugecessegas 25 1 Introduction Beginning with Release 7 1 of the firmware several improvements have been made to the ARINC 429 Decoder The vast majority of those pertain to the Symbolic Decoding driven by the User Label Definition files The system has become clearer and easier to use for those wishing to harness the power of symbolic decode We gladly thank E Schutz formerly at SRTechnics A Netz and P Lemberger at Avionik Straubing D Michaux at the University of Bordeaux B Morel and C Wittwer at Ruag A Therry at Zodiac F Raimondi at Teledyne LeCroy All of them have contributed through their help and comments to the
14. ce of Equipment was emitting Labels 102 103 104 105 in its 1978 version and additionally Label 203 204 204 in its 1995 version the same ULDF file could be used A line in the ULDF file is called a USigD User Signal Definition A USigD contains rules to interpret bits in an ARINC message The Altitude or the Distance To go or the fuel Level in Tank 4 each require a USigD Some parameters require more than a single USigD for example the Date requires several BCD USigDs A ULDF is therefore made up of one or more USigD There is no limit for the number of USigDs in a Label USigDs beginning with the same Label will appear with all Labels of that value in the annotation and the table All Labels of the same value are decoded according to that same rule as per ULDF When the frequent but not always used fields SDI and SSM are desired they will need a one line USigD per Label in which they are desired Examples are given further in this document When the frequent but not always used sign field of a binary signal is desired it will require a one line USigD Several fields also called tokens of the USigD are not used at present time but retained for compatibility with the Standard They might become useful in the future Lahniss ARINC 429 Decoder Users Manual 15 Page 4 1 3 Line Syntax The text elements explain the syntax of the ULDF files are always shown in Helvetica The line structure one a single USigD in the Comma Separated File
15. gnal for Discrete Labels The Binary format used for the binary signals only very slightly differs from the standard binary labels and allows the positioning of the Binary fields inside the message We will explore a few examples here Me Cay WEE Oe esas File Vertical Time Trigger Display Cursors Measure Math Analysis Utilities Help TR Height 61441 tt Label i 3 Height ores ee 5144 EDE j Fal 5 Faw Ravie s00 4 pe m l m et X Pe athe A A mL p fl m p g P pe Smaa i HP im P ae l s E bel alee TE T F T y tuli Mils gt R 164 Height ft 13 PosSe 0 4 Label_Discrete 16 Binary Figure 17 Visual explanation of each relevant token of an binary type L hniss ARINC 429 Decoder Users Manual 21 Page 4 3 4 Combining Signals into Discrete Labels Several USigD can easily be combined to interpret the same Label The following picture shows how the 3 USigDs used above can be assigned to the same label in this case 212 Each of the USigD used in previous example has been copied into the single ULDF file In order to avoid superposing the fields the offset and length have been slightly changed Beer Lager Distance town 322 6 Mbi Alttude 6 tt Label 2712 Distance to go 9 Raw 2 TRIN 42 ill m E en mo an 4 F f Fa i i rs M 212 Beer None Aa osSense 1 0 Min Max Label_Discrete 6 Enum Becks Lager Augustiner Budweiser 2 12 Distance to tro bht j12 PosSense 0 1 Min Max Label_Discrete 10 BCD 3 3 3
16. ly tuned Levels wc ccstscasccusssnnecusasescauiannsosuiamnpasueasinaas AE ERS 9 Figure 10 The Column to Search SCI CTO rriei iri nEs A EEE EA EEEE EE E EERE E E a 10 Figure 112 Signal Gecoded inthe 8t24 pits MOE visisuscccsacdccsesatcontasnwsusxaicesddunadtontanddeeuatocuejuennedenchapeddlanteadusuntosiepecensanscdasaiseedsaddsneataacesesuniaeadesnateneteodesunteaasienavesuauteoatseuneons 12 Figure 12 Signal decoded in the 8 24 19 241 Dit MOE cc ceccccccssecccceseccccaeseccceesecccceeccecausecessuececsenecceseusecesauececsuaeceeseesecessenececeeneceeseneecessuneceseunscessenneeessunecessuneceesagas 13 Figure 13 Example of ULDF file with several USigD for Label 273 Of a civilian GPS ecccccesseccceesececeeesececsusecceeesecceeaesececsusececeuneceeesunecessuneceseuncessenecessunecessenecessegas 14 Figure 14 Listing of all Fields of the USigD line With COMMENES ceeccccssseccccesecccceeccecausececsuececseueceeseusececauneceesuaeceesausecessuneceeeeneceeeenecessusecessunecesseneeeessunecetseneceesages 16 Figure 15 Visual explanation of each relevant token Of an enumerated type ccccceseccccessecccsesececceeccceeusececseececsenecceeeusecessusececeuneceeseusecessuseceseenecesseneeeessunecetseneceesenas 19 Figure 16 Visual explanation of each relevant token Of a BCD typPe cccccccescccccsseccccesscceceesececeesececseecceseusecessuseceesunecceeensececsunecessuneceeeeuecessusecessenecesseneeessuaeceesenecetsueas 20 Figure 17
17. me of the rendering both in the table and the annotation Usually the task at hand will dictate the Viewing Mode Note that it can be switched at any time during the course of a session The Details check box allows the rendering of low level details such as hexadecimal of BCD digits Its importance also depends on the intent of the work In some cases it is necessary to track down the origin of a value to the individual BPRZ bits of the signal At this stage a word of caution on the signal polarity ARINC 429 is usually transmitted over a twisted pair When probing single ended at the individual lines of the pair the signal appears either normal or inverted If by accident the decoder input is using the inverted signal all Label value will appear complemented to 377 In fact everything will look right even the Parity bit but none of the Labels expected for the Equipment will appear It is enough to switch the probe to the other wire to get the right information contents If for any reason the positive signal cannot be probed it is also easy to check the Invert control in the channel dialog The Invert control numerically flips the signal in the channel and avoids having to electrically invert it Note that the inversion of polarity can also occur when using a differential probe whose inputs leads have been inadvertently swapped In this case it is recommended to swap the leads and verify that the pair polarity is correct It goes without sa
18. ng Binary Data putedData FunctionalTest NormalOperation Figure 20 Table showing commonly found signals L hniss ARINC 429 Decoder Users Manual 25 Page
19. screte Labels The discrete labels can contain within the same label any combination of binary BCD and enumerated signals In this case the user is required to supply the offset in bits at which a signal starts within the label We will now go through the 3 possible type of signal that can be embedded within a discrete label Lahniss ARINC 429 Decoder Users Manual 18 Page 4 3 1 Enumerated type for Discrete Labels The enumerated type is a list of strings indexed by the value contained in the signal For this type of signal units and resolution supplied in the line are disregarded In the following Figure each of the relevant token in the USigD is visually connected to its annotation glee 2 100 OD 2 3 212 Beer None J2 1 s Label_Discrete 16 Enum SecksiLagerAugustiner Budweiser bits therefore 4 positions in enum Figure 15 Visual explanation of each relevant token of an enumerated type L hniss ARINC 429 Decoder Users Manual 19 Page 4 3 2 BCD Signal for Discrete Labels The BCD format used for the BCD signals is flexible and allows the positioning and parametrizing of the BCD fields In the following Figure each of the relevant token in the USigD is visually connected to its annotation Distance to yo 269 6 Mil Listance to qg is d Sum of Digits all Figure 16 Visual explanation of each relevant token of a BCD type L hnisss ARINC 429 Decoder Users Manual 20 Page 4 3 3 Binary Si
20. se as well as the total number of Signals It also shows the number of Signals of each type E stands for Enumerated BCD and Binaries This control is grayed out because its values are not user selectable but rather computed by the parsing algorithm of the ULDF file L hniss ARINC 429 Decoder Users Manual 6 Page 2 4 The Filter Tab Msg Pad Data SSM 300 350 2 001300 oOo DJ a j LT tT EEN TEEN TE e m T TERTE a E i SS GS a in D TESTE L y 2 001300 in 2 001300 Ped Pe Pe Pe h LI ih L L mm Dj 1 L gt Timebase 4 00 vidiv 500 msidi 2 50 ks Decode Setup User Defined View Decode Source 1 Data l Protocal Mm m ARINC429 Filter Mode Task Ele Only Show Listed Labels Only Decode Labels separated by 3 Output File DecadeTabl Figure 6 The Filter Tab and its actions when using Only Show Listed Labels The Filter gains importance when looking at long message streams It is fairly common that only a few messages require attention typically when their contents are under scrutiny Then all other messages clutter the viewing and can be left out without impairing the debug process The Figure shows the Only Show Listed Labels mode with one Label values 350 entered The resulting display shows the sparsed stream and table Conversely Show All Labels Except Those Listed applies the opposite logic This method is u
21. seful when some messages have a higher recurrence shorter time interval on the bus Here the filter unclutters the view especially when the frequent messages are not the focus of the investigation Also note that applying a filter increase the decoding performance as well as the export performance L hniss ARINC 429 Decoder Users Manual 7 Page 2 5 The Level Tab Basic User Detined Fitter The levels have to be carefully chosen to cross words of all amplitudes an the BPR signal On pathological signals levels could be asymmetric Level Type High Percent Percent Figure 7 Level Tab Controls The Level Tab contains 6 controls out of which only 4 are visible at any point in time This is due to the fact that the Levels can be specified either in Percent or in Volts with the corresponding values being shown The Level selection is largely automated since by default both levels are set to be in percent of the amplitude This simplifies the initial learning but it is important to make sure the levels are set correctly to get a correct decoding The level become very important when dealing with pathological signals Level High Figure 8 Looking at the levels in detail By default the levels are set to be at 35 and 65 of full amplitude on the BPRZ signal In most cases this is a perfect choice for ARINC 429 and immediately leads to correct decode However this only works if the signal is clean as in the Figure and
22. tails _ User Defined a oe Figure 3 The Basic Tab The Basic Tab offers the fundamental controls driving the decoding algorithm Before looking at any other functionality the Bitrate needs to be set correctly In Many cases the system user will know the bitrate and introduce it in the corresponding field As ARINC predominantly uses 12 5 kbits s or 100 kbit s it is usually a simple choice If there are any doubts on the bitrate of the ARINC stream take a moment to measure it with the following simple method 50 0 nsidiv Stop 0 0 mi 5 0 GS s Edge Positive if I ar aa A E Gaas Lel 1 e a Ly 40 60432 ms 1 Ax 102 9 kHz E _ _ lt lt _ __ S _c_ __ _ Figure 4 Measuring the Signal bitrate using the Time cursors As the Bitrate governs the decoding it is important to have it right from the onset The simplest method is to use the Horizontal Relative Cursors By positioning each cursor on equivalent positions of 2 consecutive bits the 1 delta X read out will yield the Bitrate Here we chose to measure on the beginning of each bit plateau The readout of 102 9 Khz can be rounded to 100 KHz and is good enough for the decoding algorithm L hniss ARINC 429 Decoder Users Manual 4 Page Once the Bitrate is selected we will usually start with the 8 24 bit Decoding until we have reached the conviction that our stream is decoded correctly The Viewing Mode is Binary Hexadecimal or Decimal It governs so
23. ted tokens Not used by algorithm 4 1 6 Extensions to ARINC 429 Token 12 Label Types are always Discrete with subtypes Binary Bcd and Enum Token 13 Zero based Offset in bits from bit O at beginning of message Token 14 DetailsList contains details for BCD and Enumerated Discretes For an enumerated type details would be i e Enum On Off or Enum Disengaged Engaged or Enum Off Low Medium Full In principle the number of SigBits enumerated keywords should match 2 However shorter or longer lists will be accepted silently For a BCD type it could be i e BCD 3 4 or BCD 2 4 4 4 The sum of the BCD digits should be equal to SigBits otherwise a warning will appear on the message line at the bottom of the screen 4 1 7 Unused Tokens Equipment ID Min Max Transit times Min Max values and PosSense and are parsed but not used at this stage 4 2 Examples used in this document The arbitrary labels and signals used for the examples in this document do not always have realistic contents They are only meant to be examples of encoding interpretations Any neutral text editor can be used to work on the ULDF file as long as it does not add extraneous odd characters or remove characters Lahniss ARINC 429 Decoder Users Manual 17 Page In some cases the BCD examples following contain values greater than 9 in a 4 bit BCD digit This is incorrect but due to the difficulty to generate or gather syntactically corrects samples 4 3 Di
24. ying that the polarity of the line on the aircraft is essential L hniss ARINC 429 Decoder Users Manual 5 Page 2 3 The User Defined Tab The User Defined Tab contains all of the necessary controls when working in User Defined Mode The contents are explained here but refer to Appendix A for all of the detailed explanation on Terminology concepts and Syntax of the ULDF files Basic User Defined Fitter Levels ser Labels Definition File uLDF ciLeCroyinStrea WUDLF164 te SNe Clear Figure 5 he User Defined Tab and its controls The User Defined tab contains the File Selection Widget necessary to pick a ULDF The primary modus operandi is to have a Dedicated File for each ARINC 429 Equipment When a given channel is connected to the Equipment and Decoded this File can be selected here and loaded When the User Defined mode is selected in the Basic tab all of the messages will be interpreted based on the ULDF The Browse button leads to the File Picker The Load button reloads the file when it has been edited in parallel When creating the ULDF files it is convenient to proceed step by step to verify the correct decoding while adding Signal to the ULDF The Clear button Clears the internal Database of USigD When the Database is cleared all of the Labels will appear with only Label and Parity bit decoded The ULDF Contents box reflects the currently loaded database It shows the total number of Labels in the Databa
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