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SWIFT UVOT USERS GUIDE - Mullard Space Science Laboratory

1. Description Offset 30 Channel Boundary Y5 31 Channel Boundary Y6 32 Channel Boundary Y7 33 Channel Boundary Y8 34 35 Not Used 36 BPE Safety Circuit 37 PCTHOLD range 0 gt Ox7f 38 FCTHOLD Range 0 gt 0 1 Safety Circuit thresholds 39 STHOLD range 0 Oxff see section 1 2 2 5 2 40 RTHOLD range 0 gt Oxff General Detector Information 41 Radius of Field of View arcmin 42 Boresight offset x centroided pixels from centre at 1024 1024 43 Boresight offset y centroided pixels from centre at 1024 1024 44 Boresight Offset in Roll in arcmin same handedness as ROLL 45 n 46 Damage limit counts 47 Standard Settling UVOT mode 48 standard Finding UVOT mode 49 Standard DPU Exposure slack in ticks of 1 5 second units Late Additions 50 aximum attempts at Finding Chart before abandoning 51 Event detection threshold 0 gt 255 52 Acceptable differential drift during observation units of 53 Acceptable overall drift during observation arcmin 54 Vcathode default ramp rate 55 Vmcpl default ramp rate Volts seconds 56 Vmcp23 default ramp rate 57 Vcathode tolerance 58 Vmcpl tolerance Volts 59 Vmcp23 tolerance HV Raw Limit Ranges Safe Slew SAA Operational 60 Vcathode nominal value 61 V h l cathode error value Stat 62 Vmcpl nominal value Uncalibrated units 63 Vmcpl error value 64 Vmcp23 nominal value 65 Vmcp23 error value
2. Word Description 10 DPU Image Window Size X range 0 gt 0x800 11 DPU Image Window Size Y range 0 gt 0x800 12 DPU Event Window Size X range 0 gt 0x800 13 DPU Event Window Size Y range 0 gt 0x800 14 Detector Window Size X Units 2 2 CCD Pixels range 1 gt 0x80 15 Detector Window Size Y Units 2 2 CCD Pixels range 1 gt 0x80 16 a DPU Minimum Tracking Window Area 18 DPU Tracking Frame Time seconds 19 DPU Number of Guide Stars range 0 gt 0x10 20 DPU Criteria Mask 21 Unused 22 Offset clocked position of filter usually only grisms zero if not clocked 23 Unused 24 Safety Circuit PCTHOLD Consecutive Pixel Count parameter range 0 gt 7f 25 Safety Circuit FCTHOLD Consecutive Frame Count parameter range 0 gt 1f 26 Safety Circuit STHOLD Pixel Threshold parameter range 0 gt ff 27 Safety Circuit RTHOLD Rate meter Pixel Threshold parameter range 0 gt ff 28 50 Followed immediately by the configuration for Filter 1 Grism1 with XRT position supplied 51 73 Followed immediately by the configuration for Filter 2 UVW2 without XRT position supplied 74 96 Followed immediately by the configuration for Filter 2 UVW2 with XRT position supplied 97 464 and so on for filters 3 to 10 Followed by alternative formats for different time since burst 465 Set to OxFFFF to indicate no more data 466 Pointer to address in EEPROM
3. 199JIp 5 1 9 3 04 0123130 91 OU ZOE LOAN YWIMS 1981 IAS Swift User Manual Swift UVOT 302 R03 Science or Engineering Science Science Science Science Engineering Engineering Engineering Engineering XC YC Detector Data Transmission Formats Detector 23 22 21 20 19 18 17 16 15 14 13 12 1110 9 8 7 6 5 4 Mode 0 Low Resolution Windowed 1 Low Resolution Full Frame 2 High Resolution Windowed 3 High Resolution Full Frame Engineering X M N Data Engineering Y M N Data 6 Event Height Engineering Event Height Engineering Event Energy contains no meaningful data Parity Odd X CCD Pixel Co ordinate modulo 64 high resolution or modulo 128 low resolution Y CCD Pixel Co ordinate modulo 64 high resolution or modulo 128 low resolution X Sub Pixel Bit Y Sub Pixel Bit Window ID 17 Swift User Manual Swift UVOT 302 R03 18 1 2 3 Mechanisms 1 2 3 1 Filter Wheel Eleven optical elements are placed at equal angles around the filter wheel The wheel is driven by a pinion on a 4 phase stepper motor shaft with a gear ratio of 11 to 1 Thus one revolution of the motor which requires 200 steps moves the wheel from one optical element to another and 2200 steps will completely rotate the filter wheel Number Description steps from datum The wheel position will norm
4. 330 joan 11816 110 joan dureT pue LOAN mod 104 LOAN 71 1946 pue ystperoodg LOAN WOJU I uo Jomod MOTIF LOAN HO Imod duro doi 995 Uo LOAN S8uunp euuou 9 0 siperoedg Jomod LOAN Suunp SUONRIOIA 9 LOAN I 509215 uo LOAN Suunp IMPON SUOTILIOTA PUTT 330N duel uoT OES du IG 22 4AINOIdNaLNdd SNIS 9 9 aa ee Mes SurueaJN 05 0 CO LOA 13JIAS Tenue A 1951 IIMS SNIS 9 88DSeAU LOAN oukg IWLISONASS ddaNol PRPP 59825594 10249 LOAN SnosuelInuurs oje2nsoAu LOJ STU LOAN 71 gouty NYHOONASSddANOI Sme S eges 31235 20141016 8 pue Suyes 94 LOAN UYUM eso AAWS T ALWLSLOANI AUT 9894 ojes ol 8 sey LOAN psdD
5. gt et Loy SURE SIN M99 TKA CERE CUE 4 4 34 AM 2 WM 2 TQ he sereis SD IPA 24 Peper 2 X 22 N L SELECT VETE Wr 91215 MOMS 227 1 5 co 27 8 4 2 2270 33 4 as QUT 314 x 3 gt X Cx 3 I 2 see d lt 9 ee A MI STIY SLY SMOYs SL HeXA OX x EE HA ee 92 f 9 SUE THs 3E HAE wad b gt 3 Th LES wer re 4 01 ejes 7 24 TPI 03 SI S AMORE SEX 14 Se a E 9915 in 51 SY Se AICI lt VVS EXC 5 oJ 52 SMOYS MOU 91816 Net tu Maso 5630 7777 43 e 12 d 2 teresa A uy 155 c At 24 Fw 12 Alten d E LIU S 3 M Nos A 255
6. LOAN Imod 104 522 2 391012945 LOAN LOA 1SHepedS LOAN LOA And IoAN oe Se ESATA uo LOAN Suunp SUONRIOIA 330N 300421 10 uo JOAN LOAN Suunp euuou SuoneIoOIA 9joN ppo owes 19840 mreze I sq punos3yovq_ poy JOU LOAN prey eie3nseau LOAN t d nS 90185 IY 2AI9SqO eyes nor 31235 2014 1015 993 ou isse adr Sunnooxo pu 9 LOAN empooodd paka 2 1000 e 9 5 01 103 A enueur3ou 5 PIN PPY V N PeleInoTeD ALVALNNOONdAI FYSA LOAN 1 151 3S 5 9uo8 seu MOI AUD LOAN jsiperoods Ayn 351912045 LOAN 104 I Buon f 9 8B50SeAU JelunoD PoI oq yorym 8 55 LOAN 815 LOA 1dnxrrelu sqemeds LOAN 71 31424 8 Joye opes 0 05 101 OQ IOAn 3 5 pue soolg Anf 6 21584 ol 300491 jun OISVA 0 SLVLSLOANI
7. WASHES POTN SI 721 781 XS SluleJlSuoD SIN31l ADVAYSLNI 13 232 N L 01 9 79 OU ZOE LOAN YIMS Iosn IMS SALI 440959131 soinjesodwa 9 sdoosaele 5437 poolj 991 69 XX CMA TIA Vile X 4 zi Yate Tels 144 sor As ae V l m eom 93 dx SERA Ts am 13 e EFAA DA 01 N 24 EMA JA 14 uung 24 2 WM KA FE 78 44 A 3 CX Mp mno x RPE TE it baal ved dI gt M A Fd we REXON achat 1 E FRI 541 VR gt 22 13 rc wry i a 12 5 12 Pil sat V gg cE ang 125 4299 12 13 3 c 7770
8. a4 y Vert CAS wT Fi vyu HAO TIA T 5794 prg vT Uo 63 SUA Soren Yt Ws 1 T cu 7 amp rs 34 Were ik E iam TM M Ed 21 TAMEN 0 CO LOAT1IAS SINALI NAG uaelsAS SLY 1 ysel snjejs se enue A 125 YMS 89bpc82x0 0000 0 0000 0 0400 0 0 9073194 732425 PTON 3223 335 PTON T4343 439 qesay 2222 335 39370 HTH AIS PTOULY PTOULS PTOULIJ PTOULId 413405 00 0 334 AT Zp00X0 ST AT eTTOxO ST S AT 53909170A 3d8 394 6b20x0 122 298 220 0 0 apm 0 6T lt TEZOxXO gt Tpn4j 2 6 9520 0 2747 PTZOx0 2 28 220 0 29752 lt 620 0 3d8 3da 00705 8990 0 2 5 330 43H Fiuepuo2es 330 ug 43H p4enm o 4 330 SN31U3H 0 Tae 031pooTd 131 00073 sa3eJ3unoo 0000X0 383 AH 0000X0 Tdou AH 0000X0 zdou AH bu bu
9. 83 23 s 4 _ _ _ _ ___ NSAN POT 4 __ So On oo o zo co vo so 90 zo so 6o or zr vr st ppv IDDY uonduoseg qns SPP umjeq pue sso1ppy qng 5 TILIXIAASOIIU 19 OU ZOE LOAN YIMS 1981 IMS po amDld x p 9 qpdmyoopronu 019g m Moyes 5919 09 NHSAS 45 poem x TORS ppousemppjexipjerurwW G IOHL juno 4 oAnnoosuo A 40 SINVY 01 5599028 ou 1200 01 559996 pue parey 50200 GOO 0 ap 9Anoy pojqeug Sae ON 1 unoD ouie1 oAnnoosuo TIOHLOd 105095 95109 M A Io same 1v WA VI 84 so 19351893 MAMO OV TALYAT vonda 1102 PLUI 2QV da 0993 sseuppy 105495 eut SnlelS AH Jexid qns x 1 uoq unieq slqel wnq 2129 1 109 wnq SW at x 33 luoq SnlelS S91u04129 3 10190190Q GIOHLOS x L dio3u z 1 Ajeyes 84x0 857 2 00 21 6 sug
10. Swift User Manual Swift UVOT 302 R03 B 23 Word Description Offset 66 Vcathode nominal value 67 Vcathode error valu 68 Vmcpl nominal value Slew state 69 Vmcpl error value Uncalibrated units 70 Vmcp23 nominal value 71 Vmcp23 error value 72 Vcathode nominal value 73 Vcathode error value 74 Vmcpl nominal value SAA state 75 Vmcpl error value Uncalibrated units 76 Vmcp23 nominal value 77 Vmcp23 error value 78 Vcathode nominal value 79 Vcathode error value 80 Vmcpl nominal value Nominal 81 Vmcpl error value Uncalibrated units 82 Vmcp23 nominal value 83 Vmcp23 error value 84 Settling Exposure Catalogue Search Radius 5 ED Units arc minutes 85 Settling Target Pointing Limit Tolerance on HV noise 86 Vcathode noise toleranc 87 Vmcpl noise tolerance Volts 88 Vmcp23 nois tolerance Exposure overheads includes DPU slack and BAT warning waits 89 AT Exposure overhead Units are seconds 90 PT Exposure overhead Exposure Thresholds used when processing GRBFLUXINFO to determine if bright 91 A 92 Setting Exposure Threshold 93 94 Exposure Threshold 95 96 Bright GRB Threshold RTS Index Address of start of RTS Index table B 4 Warning BAT about Filter wheel movements 99 BAT warning delay 0
11. 0 2 0 0 73 Illegal APID 00 hex This verification error message is issued when a command with the indicated APID and Function Code is received with an APID outside the valid range 1 APID received P2 0 C 74 Illegal APID Length 0e hex This major anomaly message is issued when the ICU attempts to issue a telemetry packet in which either the packet length or APID is outside the expected range Swift User Manual Swift UVOT 302 R03 14 P1 APID in hex P2 Packet length in hex P3 0 C 75 Illegal Function Code 08 hex This verification error message is issued when a command packet with the indicated APID and Function Code is received with a function code outside the range expected for the packet APID C 76 Illegal Memory APID 0d hex This error message is issued when the APID provided to which to dump memory was invalid P1 APID sent 2 0 0 C 77 Illegal MID 0b hex This error message is issued when the MID memory bank identifier from which to dump was invalid incorrect MID P2 0 P3 0 C 78 Illegal Parameter Values 04 hex This verification failure message is issued when one or more of the parameters in the command with the indicated APID and Function Code is outside the expected range see the Command Table appendix D 2 in the Message Codes appendix for a list of the APIDs and Functions Codes C 79 Illegal Start Address 0 he
12. Fed 9638 palooqeI sey 12940 IOJ uondooxq E isqerods LOAN uuopup pOd I 3ngeq S zHOLHdHOVS 1 175 20664 82 5 twos joan 3 urpeow 1 YUT 5108098 Kqreou yosdD 104 Z 5 9 LOAN WOJU S zHOLHdHOVS 71 175 20664 82 5 5 Fed 3 urpeow 1 YUT eed dogs TIG 5108098 Kqreou Jo 5 Ssmo LOAN ru pe pes MOT MOT 87 COU COL LOAN YIMS TenueJA PSAN IIMS JO SI Sse un uoxe oq UOTIDeS go UON ou pue 005 UIM Jo 1004 Joye sSurpeal 8111 6 ISSW 995 sem sL LON aoe ud do3 se3ou ees LOAN WOJU LO 1 NdONOI dWaALNddI t 330 joan 17816 22 pe 51181 IMPON 18190945 LOAN SLOT Lu VE 46 LOAN uuojur 104 HO MOA deeds naa Jomod LOAN 8 suonv ora pur 930
13. r 333X r 331 x X 4 2 DUUA aT YH ME E SoluoJloal3 4012 124 Pope b 1 Pg Ved 2 02 4 EI Mer X M MOM s _ 1 ecg x Vd gt FNAL K LEE 7 iel el 5 2448 tA X 7 5 9 SI FAA X 97 A 1 de 33 A Alten 32 wre rj Zap sep MI C Ae LA r3 0 cOA COE LOAN AIMS SsJosuag uonisod 1994M 49114 2 st 2 st A A nura M 29 3 L ce v gt ran gn TM pau rd Moa dep nx trn Lp nx trn wis Lp x 145 SD an fS w m24 Pu 9 qim watt 724 te che MME OW TES Eh NS rtt mps A 141 rn 4 M a e A
14. 398 3405488854209 2614 JSUG UT 4 aur Mj SHSINUHA3H 2570 Jepn8ug u34e3 8 JST 08T 2570 JeTnauu uns 3UTeJ3suo U3Je3 3uTeJ3suo uoo 3uTeJ3suo uns SLNIbALSNOD AN AN AN up gt pad u0 484 ug 1943493 57591 30 501915 00x0 00x0 28 0 Texo gexo 5158 10x0 4236 Iss peej peo peo 520 dung way peej aT 2723 AH 821 Sopu23eM 583154109 ASYL dae sy 3ej Jeas 155 peej des sg 4 peo 521 eun way anTTH anTTH peej daa sg ITI anTTH OJ3uj SATIY 4247390 dues AH SATIS 821 51501 3 9 1 405 21598 Pid 679726 pT 90 70 002 an Segcxo 55848044 Snqgeg 0000x0 IST 0 3cdnJJa3uT ngeq 91830 ON 8 3 3527 SuoN 21 3827 0 34103 142134 3ueJ4m 0 4unoj 3 000 070 ReTeg 3noeuwr 3227 TewJoN quang 3527 3527 0 uadeg Sly quesung 0 O
15. PND Ded 12 3 15 12 Peel 158 V l nad 15 4M 18 Ist 44 c 777 KRA TF 24239 292 NA gt Ww TUUM SAFER AF VE amp CISEX ED PS THN Tee NS 99 Bojeuy peiqesiq pejqeu3 53521 0 07m 2 2a ote Th 37 rr coe SYS BI X z wood SEI e JS 341 X MT J Ed Li ford P pss x vri cee tag st M9 JG 40648 Sb PAZ 24 VETE MET E 2 14 X coe 5 9 43 Cites LEE Twl ee 5 41 p tz M Awe DX OX Taner 4l 1 au 94 3 THES kz wad b 2 po 4 7 2 232 2 E Tn k 4 5240 7 43 sell 2 paix c dr rvs tld Ala 9p 255 M z HO lt re Fd eyy Arn fa wire EEIE uM Mags prg sa at SIENA bI 4 84
16. 5 94 LOAN WOJU 104 71 LI GI IIHO06SQVHOVS osed Toistaa 5105095 12949 T noL TESTENE WNL 151212245 And LOAN WOJU 104 71 esusu SLOANE SmelS oq soSessour LOAN po qeugq 5 9 LOAN WOJU S ZHOludHOVS LI SI IIHO06SQV3OVS Jojsmueup Fed WL 5105095 12949 ANG LOAN WOJU 104 1 Jojsruumu p T WL OUSeI awns LOAN payeroosse oq soSessour 10119 LOAM FNS LOA 3sIefoedSs LOAN 104 71 HOLYdaOWS LT STI IIHO06SQV3OVS wos joan 1 5105095 42942 apes 22122 k G ZHOLAdHOYS 71 175 20664 82 65 Fed Surpeox 3 di o8ed pu SINUS 9 LOAN armnpooo
17. SWAI 99 I98uofT ou Mq DALY FLY JOU UIT suomnoe 8141 UON jeu 0 12942 pue sdnyorq sequosep sfqel STY pue ol LOAN Surpuas YIM IOP FO ou st RULIOU UNI 0 oui 10 ur sooid ou jeu TION CENSIANOIANS TVIANXSHYL ATAVLS AJAN LA 25 oq e snjd 1940931 01 sessed TIM LOAN ewou ser dde o qe1 5141 San eu ol e8ed SYAS L 1253 poys pue esuodseg 2 9v OU ZOE LOAN YIMS TenueJA 314 2 LE GT TTHOO6SGWHOWS u3os3oAn osed dWul sddI osed 2 5105095 12949 T ee astetoodg LOAN 104 71 S ZHOludHOVS LI GI IIHO06SQVHOVS Fed upLog XUT TOSTAL 5105095 12949 T 2 im
18. 11 D 12 D 13 D 14 D 15 D 16 RTS TABLE ICU COMMAND TABLE TYPES OF FILTER WHEEL MOVEMENT FILTER TABLE MAGNITUDE CODE TABLE COLOUR INDEX TABLE PLANET CODE TABLE STATE TABLE HEATER TABLE DCS EVENT CODE TABLE LIMIT ITEM TABLE TASK IDENTIFIER TABLE HV CHANNEL CODE TABLE ICU ERROR EVENT CODES IN NUMERICAL ORDER ICU ERROR EVENT CODES IN ALPHABETICAL ORDER PACKAGE CODES IN NUMERICAL ORDER Appendix E Telecommands E 1 Telecommand Summary in Alphabetical Order Appendix F ICU software NCRs and ECRs C 17 C 18 C 18 C 18 C 18 C 18 C 18 C 18 C 18 C 19 C 19 C 19 C 19 C 19 D 1 D 1 D 3 D 6 D 6 D 7 D 12 D 13 D 13 D 14 D 14 D 15 D 17 D 17 D 18 D 22 D 26 E 1 F 4 Swift User Manual Fil 2 4 5 F 6 F 7 F 8 F 9 F 10 11 12 F 13 F 14 F 15 F 16 F 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Goddard NCR SWIFT2002 103006 Goddard NCR SWIFT2002 103007 Goddard NCR SWIFT2002 112002 MSSL NCR 22 Basic Code MSSL NCR 74 BASIC code MSSL NCR 75 BASIC code MSSL NCR 76 BASIC code MSSL NCR 77 BASIC code MSSL NCR 78 BASIC code MSSL NCR 79 BASIC code MSSL NCR 80 BASIC code MSSL NCR 81 BASIC code MSSL NCR 82 BASIC code MSSL NCR 83 BASIC code MSSL NCR 94 MSSL NCR 110 MSSL NCR 117 MSSL NCR 121 MSSL NCR 125 MSSL NCR 129 MSSL NCR 132 MSSL NCR 134 SERS S 0067 MSSL
19. 0000 noaction 0001 line 0002 h_basic 0003 h_emergency_safe 0004 h_tm_off 0005 h_uvot_off 000b h 11 000c h 12 000d h 13 000e h 14 000 _15 0010 ok_to_slew 0011 gotosafe 0012 emergency_hvoff 0013 autostate 0014 process_slew_warn 0015 slewabort 0020 test 0021 idpumode 0022 dpu_abort 0030 do_exp 0031 start_exp 0032 end_exp 0033 interrupt_exp 0101 controlled_off 0102 controlled_tmoff 0200 pokedataram Swift User Manual Swift UVOT 302 R03 RTS Name RTS Number in hex 0300 0301 0302 0308 031a 0323 0324 0325 0326 0327 032 0334 0345 0366 0377 038 03e2 03e3 03e4 03e5 03e6 03e7 03 0313 0344 03fa 0402 0403 0404 0405 0406 0407 gotobasic fastsafe do_slew gotosaa safe_to_idle slew_to_settling slew to fc slew to at slew to pt slew to safep slew to idle settling to fc fc to at pt to safep to safep saa to idle send slewsafe get sttlng config get fc config get at config get pt config get sp config bright planets do sttlng exp do fc exp obs to idle hvon hvoff hvnominal hvsaa hvofffast hvidle or saa D 2 Swift User Manual Swift UVOT 302 R03 D 3 0 2 ICU COMMAND TABLE Note an APID in the range 670 to 67f hex indicates that the command was issued on board from an RTS and therefore will not be observed in basic state The table is ordered by APID and then function code F C See also Telecommand Summary in Alphabetical Ord
20. 330N amyesodwiay apis Ajddng dog i asd NSHI 5 go 220 AIddns snid 903 ees 110 joan 32235 pue LOAN HO Mod LOA TZ 11946 suorsinoxo LOAN 1 T go Ajddns sn do ees jsmperoedg ANG LOAN 104 71 LOAN 104 71 2 pu 8 Teurou yur 9 0 pue uo LOAN Suunp SUONRIOTA yur 9 0N nad so3ou aas Ajddns Az snum go AG ees sqpemeds LOAN WOJU ASW pue Jomod 8 ewou HUTT 3 0N uor3oes QOUdIIJOY 5114 ees 444 uoy pur uoy WUT 40 2A 8 66 0 LCOE LOA 1JIAS Tenuen 1250 31A S ongea seg oy 01 2024 Joan ut 3oBJIelUT
21. EH Swift UVOT 302 R03 Magnitude Range Swift User Manual Magnitude Code Decimal 131 Hex suy EN EN eal ES EA EA EA ES EN Ea EN EA EM E EN EA EA ES Swift UVOT 302 R03 Magnitude Range Swift User Manual Swift UVOT 302 R03 D 6 COLOUR INDEX TABLE The colour index used in the star catalogue is a B V in Johnson magnitudes The larger the code number the redder is the object The codes represent uneven width bands as shown in the table below BV lt 033 0 33 lt B V lt 0 27 0 27 lt B V lt 0 17 0 17 lt B V lt 0 11 0 11 lt B V lt 0 01 0 01 lt B V lt 0 15 ree enven ere ERLE gt C e ps Swift User Manual D 7 PLANET CODE TABLE JUPITER SLEW SETTLING FINDING AUTOMATED om Swift UVOT 302 R03 Swift User Manual Swift UVOT 302 R03 D 14 D 9 HEATER TABLE INTERFACE FORWARD METERING_RODS SECONDARY_MIRROR D 10 DCS EVENT CODE TABLE Event Code Event Description za NORMAL_DELAY 1 AT_REQUESTED_HV 2 AT_REQUESTED_FILTER_POSITION 3 DPU_MODE_READY 4 DPU_ACK CENTROID_TABLE_LOADED WINDOW_TABLE_LOADED 7 za 7 NEXTOBSINFO WITHIN 10 ARCMIN 9 SETTLED CHAIN CODE SLEW START 12 BATGRBFLUXINFO packet received 63 Issued by RTS gotosafe_tdrss after SLEW_START WITHIN_10_ARCM
22. Entry or exit from the SAA as shown by a flag in SISCATTITUDE record In addition an error may cause the ICU to select and run an RTS to handle the condition These typically involve FINDING 4 2 ie o gt Nominal Related Watchdog Kick PT or Safe Point Emergency Max Exposure Other Swift User Manual Swift UVOT 302 R03 33 going to the Safe state The precise action is determined by EEPROM located tables The errors are Limit Violations see appendix A 4 for details of the EEPROM table Error condition caused by e g failure of a filter wheel move CRC check failure set see appendix B 8 Errors Action Table for details The Safe Hold flag being set to true in the SISCATTITUDE record The purpose and activities of each state are summarized below BASIC CODE ONLY Basic The ICU enters this state on turn on The code executed in this state is resident in ROM and therefore cannot be updated It ensures that the filter wheel is in the blocked position and that the high voltages are at zero It maintains housekeeping on board autonomous limit checking thermal control and enables the watchdog see section 1 1 1 5 These latter processes continue to run in all other states On command to go to the Safe state it first loads the operational code from EEPROM into RAM and then performs the transiti
23. SUHAN 1 03195 st pojqeug a cH URN UO 1 SrolesH 0197 po qeuo 3 84 105095 9STeoo JO 1091100 194 juno oAnnoosuo LS 1010 PM p YSnoIy 95244 td Cd Td 14 1 SeSelIOA _____ JO p 595994 opoue 11211 Ajoyes a saseyoA VAS UIM So sumed 10 493 10 49 Ee wanno G37 Pool ssappvxnn 2 a S x ______ dnyoo sseuppy dnyoo1 IN Sseuppy dn oo1 SseJppy ejqe anyoo rea aposseooyalqe 8 0 1 __ TOBE opoeleg seippy x Sseippy deuig sseppydeuwg sal QIOH LY EX 6 1 sug CIOHLS ___ azaesfeu uno LAST 0 w quld xbespedhnoloAeeSs PO HT eH amp X eeokdg Ionuooduselioon Poe OG _______
24. 7 CA 5 9 i WA au t 51 AO sg m yox 2 2 Pi TU LI ord tu sell o6 4 1812 TJ 155 277 si MAG SD been eee SEIRE EWA 2 4 So YT OF ID 724 prg VT 4 19 3 E Aou v3 r5 iat tw 1 88904 777 Da 11 epo p r e U wr cL 42 Ke nez sug THs 2 LI 774 52 7777 43 rw MI k E BMI LAM bw C 78 Were uUoWisueJlL lt 51 YSL M S JULA eu os poystuly sey JO pue alelS 69 COU COE LOAN AIMS enue A 125 YMS
25. B 8 Errors Action Table This table contains a series of contiguous records that describe the actions the UVOT ICU should perform in the event of certain NHK error message being generated Up to 256 records are allowed A CRC for the whole table is then appended The format and meaning of each field of a record is described in the table below nord Description Offset E 0 Error code and action bits see Word 0 table below The action is only performed if a match is found with both the error code and the NHK 1 parameter value see next item Value to match against 1 parameters of NHK message action only performed if match found with 1 error code and this value If this value is OxFFFF all values of the NHK parameter match The NHK messages are described in Appendix C The code number of the RTS to run in the event of a match being found see table D 1 for the code values A value of zero indicates no RTS is to be run Word 0 Table The contents of the word at offset 0 are as follows MSB LSB 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 X X X X X N 5 NHK Error Code to Match see Appendix Where X Don t Care N Ifset e g by a bit mask of 0x400 any specified RTS should not be run if the is in the Safe state S Ifset e g by a bit mask of 0x200 forces the UVOT to stay in Safe state afterwards T
26. P3 Current line number in hex within that RTS The ICU s response to this message is determined by the logic of the RTS it happens to be running For a timeout on the within 10 arc min flag settled flag arrival of a FONEXTOBSINFO record or the start of a slew the ICU runs the gotosafe_tdrss RTS For a timeout on a filter wheel move the ICU will attempt to recover by moving to the datum position and then retrying If that fails it runs the gotosafe RTS For a timeout on a HV ramp the ICU will take appropriate action to return the ICU to the Safe state For a timeout on a centroid or window table load after a retry the gotosafe RTS will be run For a timeout on a DPU Ack or DPU mode ready the ICU will run the blocked_tdrss RTS 25 DCS Exiting RTS 83 hex This event message is issued when an RTS completes normally 1 Current RTS number in hex see RTS table appendix D 1 in the Message Codes appendix Swift User Manual Swift UVOT 302 R03 C 8 C 26 DCS Insufficient Priority 76 hex This event message is issued when an RTS is unable to run because another RTS of a higher priority is already running 1 RTS number of rejected RTS in hex see RTS table appendix D 1 in the Message Codes appendix P2 Priority of currently running RTS hex P3 Priority of rejected RTS hex C 27 DCS Invalid Command Token 73 hex This error message is issued when an attempt is made to execute an invalid comm
27. disabled units 0 1 s see note 1 100 Early in burst definition is lt this value units 1 s Swift User Manual Swift UVOT 302 R03 B 24 Word A Offset Description Config Addresses 101 102 Address of start of AT Configs table B 6 103 g 104 Address of start of PT Configs table 7 Grism Positions 105 UV Nomimal Value 200 106 Visible Nominal value 1000 XRT Position Calculation Axes Bit Flips 107 Invert sense of x y roll 1 2 4 masks Spare 108 aximum Count Rate 109 Safety circuit Pcthold value in slews 110 Earth avoidance angle in slews minutes of arc 110 gt 126 Spare locations 127 CRC of Table Notes The BAT delay should not be any higher that 3 seconds If this occurs the filter wheel timeouts may trigger on time consuming movements e g going to datum Swift User Manual Swift UVOT 302 R03 1 Appendix Error and Event Messages C 1 Overview NOTE Normally there is an automatic response by the ICU to any errors The parameters associated with each error are normally interpreted by MSSL staff Listed below in alphabetical order are the ICU NHK Non periodic HouseKeeping and Verification Error messages that may be displayed on the ITOS icuevents window the error event code for these messages are given in brackets The DPU event messages forwarded via the ICU are also given for conve
28. e g by a bit mask of 0x100 an echo of the NHK message is sent on TDRSS The numerical values of the symbolic constants shown can be in seen in tables D 14 and D 15 and in the part of the Message Tables appendix Appendix C associated with that particular error The codes of the RTS to be run can be found in table D 1 and section 1 3 8 2 Summary of RTS Scripts Note the working copy of this table is located in RAM starting at address 0x900 It is therefore possible to change locations in this table on the fly using the iicuload command e g iiculoadl mid 0 offset 0x900 record offset word offset data value where the items in are replaced with the relevant values For example in order to change the action associated with TIMESYNC_Jump error to that of noaction the data value from section 1 3 8 2 needs to be a zero From the table below the offset address of the record containing that action code is 150 From the word offset table above it can be seen that action codes are always loaded into offset 2 within the record Therefore the command would be iiculoadl mid 0 offset 0x900 150 2 data 0 It can also be seen from the table below that the Error code and action bits field word offset zero normally contain 0x400 0x100 25 N and T bits set plus an error code To also force the UVOT to stay in safe after the error occurs i e the S bit is set bit mask 0x100 the value
29. 110 joan AMG LOAN UOTIDeS go 32235 pue p4 LOAN Jo Mod I pue do3 ees pur uo LOAN 8 SUOTIEIOTA 9390N uo LOAN Suunp SuoneIOIA 30 WAAHI 10 y3 SI sse un Ueyel oq jo UON ou pue J009 UIM 1o 1004 si 68 ISSW 998 1 po qesirp SUL ALON omjerdurg do sajou ees LOAN 104 I uoT1o9s 20 dyo don Ie SAOU ORE 33071enod 40An B 529 ko M imd 31225 pue ompoooid LOAN Jo 104 7 pue MOTOS LOAN LO T UOT ROSS 9 LOAN 1 do3 59301 ees istperoadg LOAN 104 71 apts v A ddng pue uo Jomod LOAN 8 suone ora yur 930N 1008 pu a uo LOAN Suunp SuoneIOIA
30. 3 Powering off the telescope is normally no better than leaving it powered with the high voltages powered off When in full SAFE state not the same state as SLEW the high voltages and normally the camera are not powered and the filter wheel is in blocked There is no gain from the MCPs Powering off the TM when in SAFE powers off the interfaces and heaters It does not provide any extra safety unless something has already broken or is out of control 4 UVOT DEM is able to command the filter wheel to its blocked position A simple power off of the telescope module may well leave the filter wheel in a filter other than blocked thus allowing the passage of and potentially damaging light After the DEM has commanded the filter wheel to the blocked position the TM can be powered off but there seems little point unless the DEM has lost control 5 only known reason for powering off the UVOT TM is if the DEM has lost control of the TM This could be caused by a failure to boot a serious interface problem etc The DEM can already request TM power off when it finds it can t control it The Spacecraft can already power off the TM when the DEM doesn t respond to a slew warning There should never be more than 1 DEM powered There should never be more than 1 TM powered The TM should never be powered alone Some light can get around the blocked filter to the detector but observing e g Capella with the blocked filter is not
31. 3 The intensity of as transmitted in the GRBFLUXINFO packet by the BAT instrument Which exposure is used within that sequence is a function of the time since was detected This time since burst selects a given time band The next exposure configuration is then selected from a cyclic sequence specified for each time band unless in a previous snapshot a specified minimum exposure time was not obtained in which case the current one is restarted Upon completion of a given exposure the UVOT resets itself by transitioning to the current AT state It then selects the next exposure configuration This process repeats until the next slew warning It is possible for the above behaviour to be modified If the finding chart exposure was not successfully obtained in a previous snapshot perhaps because the snapshot was too short or it was interrupted by entering the SAA the UVOT will first transition to the Finding Chart state and retry the exposure Up to three such attempts will be performed before they are abandoned 1 3 11 6 PT Observation NOTE For all types of exposures the ICU maintains a running theoretical total of counts received so far at each catalogued star position in the field of view Should this number approach an EEPROM tabulated damage limit it will shorten or even suppress the exposure accordingly See also SAA Interruptions section 1 3 11 8 below The UVOT Mode supplied in the FONEXTOBSINFO is
32. 550 joan 1189146 pue Moot UGH v4 eipoooud W L HO mod si eroodg Ayn Ep 8 SITeT And LOAN ju gt LOA 1 440 T Me eevee Tide D S HIOVI IOAOSI u32s30o4An aed E AEN ol 92942210407 azed jjo Pom hound WL ol onp jou soy LOA 35112245 LOAN T LOAN LOA I IASB eyes 31235 20141016 pu 8uUeS 9 LOAN uyum 4 104 dnrreluI 5SST amp 4nq LOAN WOJU 104 71 unoD JOU ESC 54044454415 2128 LOAN oq YOIYM soSessour LOAN Snoouej nuns oje3nsoAu LOA Jouueu ESSI T3NNVHO SGTOS 15112245 amp nq LOAN Wozu I LOAN Sjoxoed PRPJ UprUA 8 5 10119 LOAM snoouej nurs oje2nsoAu LOA LUZLY Peg SlNOdGavaluziWu smperods LOAN WOJU 104 71 Jo JequinN 3454215661951 eyes 31235 20141016 pu 9 LOAN UsellUA moog 104 7 snur 3sIefoeds LOAN 104 7I OLHIESSTOS 0 MOTPA pos KoT Mor 8 cS O COC LOA T13JIAS Tenue 950 IA
33. RTS Number Header Length PT_CONFIG_ID_ID RTS_NDX_ID RTS_NDX_HDR_ID LIMIT CHECK TABLE 2 ID HEATER TABLE 2 ID C 21 Count Rate too High dd hex This event message is sent when the calculated count rate for a catalogued star in the field of view is too high in this filter to safely proceed P1 Star number counting from one and indicates which associated Catalogue Star message to examine for object details P2 0 P3 0 C 22 DCS Aborting 70 hex This event message is issued when an RTS is requested to stop either by direct command or if an event has occurred that requires a higher priority RTS to run 1 Current RTS number in hex see RTS table appendix D 1 in the Message Codes appendix C 23 DCS Call Depth Exceeded 74 hex This error message is issued when an attempt is made to call an RTS from another RTS that is too deeply nested 1 is set to hex P2 Current RTS number in hex see RTS table appendix D 1 in the Message Codes appendix P3 Call depth in hex The ICU response is detailed in the Errors Action Table C 24 DCS Event Time out 81 hex The event message is issued when an RTS is waiting for an event e g the end of a filter wheel movement that does not occur within the maximum anticipated time 1 Event code see DCS event code table appendix D 10 in the Message Codes appendix P2 Current RTS number in hex see RTS table appendix D 1 in the Message Codes appendix
34. S 1 81 LOAN Sjoxoeq PWPP oq 10249 LOAN SnosuelInuurs 8 IOJ 51 11 pue 8 NOI LOAN 10 SI 661 JOD LOA X Jo 151212945 LOAN LOA 1 jse 0 204d JOAN ur ay ssed yxou 991 104 0 st WL yosdD IOd v 1 unoD LOAN Pd PNPP oq 59825594 10249 LOAM snoouej nurs ojegnsoAu LOJ SSUGL 151210245 LOAN 1 poywodar 1521 01 2044511 JOAN oy ssed aIoJeg Od 9 3 5 pue soolg Anf 6 3unooqerioprsuo IOAD 6 aws LOAN OL PRPJ UprUA 8 LOAN SnosuelInuurs 8 peg OISVE 0 SLVLSLOANI 8ed Jo 2154 1 9781 LOAM poroogel sey JOD sqpereds Ainq LOAN I E snies ayes 31235 20141015 Sunnooxo pue Suyes 94 LOAN UYUM MOJOJ 9519 AAWS T ALWLSLOANI AUT 9
35. Swift User Manual Swift UVOT 302 R03 3 Fault Trees 3 1 Safety Circuit Trip ICU Transitions to Safe State Determine nature of bright object such as Bright Star Comet Bright Background Too close to moon etc Determine whether future PTs and ATs may observe this field and alter AT and PT tables accordingly Wait for next slew if necessary to avoid bright stra in this one Run start icu_idle 70 Swift User Manual Swift UVOT 302 R03 3 2 TM gets turned off Fix Spacecraft Problem Check logs for any late UVOT ICU Slew replies Run start uvot recovery 3 3 UVOT gets turned off Fix Spacecraft Problem Run Start UVOT Power On 71 Swift User Manual Swift UVOT 302 R03 3 4 ICU has an error not covered above The ICU transitions to Safe State Check that Safe state is OK Contact Phil Smith at MSSL 3 5 ICU reboots and ends up in BASIC State Contact Phil Smith at MSSL Run start idebug Ensure a pktdump is created 72 Swift User Manual Swift UVOT 302 R03 73 3 6 ICU has a limit violation Contact Phil Smith at MSSL Examine Other Sensors for example on spacecraft Try to Determine if it is a faulty sensor Check status of all heaters
36. Tables section 146 CRC for whole table Swift User Manual Swift UVOT 302 R03 B 20 B 12 State Change Table In order to achieve its goals the ICU must successfully transition the UVOT between several instrument configuration states Each state transition is performed by a RTS This look up table contains a list of those RTSs against the requested transition For those transitions that may be autonomous see below it also contains the required state of internal ICU flags for that particular transition to take place Note these items are shown with a grey background in the table below This table is used in two ways 1 On command The table is scanned for a match against both the current state and the requested state If a match is found the relevant RTS is selected and executed If no match is found the command is rejected 2 Autonomously Certain events will cause the ICU to self select the required state transition It compares internal ICU flags against the expected values given in this table If a match is found the associated RTS is executed If no match is found no action is performed The events that trigger such a response are settled flag becoming false in SISCATTITUDE record The reception of the FONEXTOBSINFO message e within 10 arc minutes of target flag being set to true in the SISCATTITUDE record Entry or exit from the SAA as shown by flag in SISCATTITUDE rec
37. The information in this table controls the algorithm and consists of a Whether an item should be monitored This facility is provided as 1 There is no support for the detector safety circuit in the basic code and therefore this subsystem should not be monitored by that code 2 During flight due to a failure condition we may choose to cease monitoring of a particular item to avoid multiple error messages b The frequency of monitoring and the phasing of that monitoring within the cycle c The valid range of data in raw i e un calibrated units d The number of times the range must be exceeded before it is considered an error this is to allow for noise on the value e The recovery action to perform in the event of an error 1 For Basic code this will be a no action a request to the spacecraft to power down the telescope module or a request to power down UVOT 2 For Operational code this will be either a no action or a request to run an RTS Swift User Manual Swift UVOT 302 R03 Appendix Detailed Description of EEPROM B Located Tables B 1 Location in Memory Name Start End Comments Stat Painters 00000 01412 Index into star catalogue permits rapid access into relevant section for current exposure see next item Star Catalogue 01413 6F26C Star Catalogue including position magnitude and colour Star Catalogue Addendum 6F26D 6
38. vol 1 Moscow NAUKA 1987 stars listed in the General Catalog of Variable Stars with max V lt 11 0 were processed Missing B values were set to V 0 3 Seven objects were removed from the GCVS catalogue prior to processing These five supernova remnants were removed completely because their maximum V magnitudes had faded significantly since the supernova events had occurred NAME RA DEC All 2000 coords hh mm ss dd mm ss S And 00 42 43 0 41 16 04 B Cas 00 09 10 7 59 08 59 Z Cen 13 39 57 31 32 2 V0843 Oph 17 30 37 2 21 28 51 Tau 05 34 32 0 22 00 52 1 Another 2 objects were removed from the GCSV catalogue because they already existed in the Yale Bright Star Catalogue NAME RA DEC All 42000 Coords hhmmss ddmmss SS Uma 14 02 03 54 27 9 VW Vir 12 21 164 09 25 1 NGC The Tycho catalogue does not include extended sources thus the NGC2000 catalogue ref J L E Dreyer edited by R W Sinnott Sky Publishing Corporation and Cambridge University Press 1988 gt was used as the source of the brightest extended objects in the sky 800 objects brighter than 11th magnitude Swift User Manual Swift UVOT 302 R03 B 4 AS we are interested in the brightness per unit MIC coincidence loss area and not the total magnitude a program was written to calculate the average surface brightness given the magnitude and spatial extent of th
39. 10 seconds the exposure is suppressed The catalogue is stored in EEPROM It is divided into three contiguous sections the main catalogue the addendum and the pointer table The main catalogue This contains stars down to 12 magnitude As the detector is more sensitive to blue than to red wavelengths sources that are too red to affect the detector are filtered out Over 200 000 stars are stored derived from the Tycho II GCVS III NGC and Yale Bright Star catalogues For efficiency of access the catalogue is split into 2524 sky areas of approximately equal solid angle in 44 declination bands Within each area the position of each source is stored to half an arc minute accuracy in the right ascension and declination axes relative to the origin of the area along with each source s associated magnitude and colour information Each sky area is followed by a CRC value for memory corruption checking The addendum This is an area left blank in case any sources were omitted from the catalogue prior to launch At minimum it consists of a marker to show that there are no more sources stored and the remaining memory zero filled except for the last word which is a CRC value If a source is added to the addendum then it will be put at the beginning of the area and followed by the marker The pointer table This allows quick access to catalogue data It holds a set of pointers that via two levels of direction point to each sky area It is CRC
40. 1000 Performs settling ezposure switches to finding chart exposure when settled flag goes true 18 32766 Contingency RTS Sets all HVs to zero without controlled ramp down Stops BPE events failsafe turn off flood LEDs awaits end_exp 50 0 completion of any centroid table load signals ICU to stop counting events Goes to state Safe quickly Filter wheel to blocked Vcathode fastsaf REIR set to zero other HVs ramped down in 5 seconds each ENTE 837 1000 Called at end of finding chart exposure Performs multiple AT exposures until next slew get at config 997 0 Not used get_fc_config 996 0 Not used get_pt_config 998 0 Not used get_sp_config 999 0 Not used Swift User Manual Swift UVOT 302 R03 28 RTS Name Code Priority Description get_sttling_config 995 0 Not used HVs set down quickly Vcathode set to zero other HVs tob G 21 ramped down in 5 seconds each Goes to Basic state Performs transition to SAA state Any exposure is tidily gotosaa 776 1000 interrupted and HVs set appropriately No filter wheel movement performed gotosafe 17 32763 Performs nominal transition to Safe state from all states in operational code Same as gotosafe except that a DCS Timeout message is also gotosafe_tdrss 1537 32763 sent to TDRSS as it is called after timeout on waitfor instruction h_11 11 32767 Placeholde
41. 5 x 0 dioau z 195 HNO Aiejes 9 52 sug indino q1OHIH L dio3u Aiejes 857 ou 1 61 1ndino JeleN 0 dI53H JeisiDeg Ajeyes 1 uoq jueung Josues 09 nSdWNL SO xou 80 2 jefe a EU wnq uonduoseg SOVIN ased SOLI 99 991 ur pue pueuruoo Ye JAodsy YSL L 991 ur 9 OU ZOE LOAN YIMS 1981 IAS Swift User Manual Swift UVOT 302 R03 63 2 5 6 ICU Basic Special Considerations When the ICU is powered up or reset the ICU Basic code is run The code is stored in PROM As a design precaution against possible undiscovered bugs in this unchangeable code some delays are placed in the code to allow time to prevent certain tasks from starting should a a bug be discovered in them or b an EEPROM table they depend on has become corrupted The tasks concerned are the heater control stopped with an ihtroff command limit checking stopped with an ilimitoff command and HK stopped with an ihkoff command If these commands are issued prior to the relevant task starting this occurs 18 s after the start of the power sequence they will be placed in either a suspended or initial state depending on the relative times at which the internal start command and the exte
42. 7000 dwa 40304 0786 9 802 amp Oopz 6 68 39 68 T eg 8000 0 0800 0 UG 9200 0 UG 9800 0 85 9p00X0 ST 1 57 9000X0 82 0000 0 55795 0 3507 53594 G6GT 446 d 21 95795 446 69195 0 40443 95735 446 SWI 69735 69195 8 Tuy oufis eur ug 19156 0 5391 4 544940 297 SWI Y 544940 SddT 0 3495 155 0 peg ISS 97 34103 poog 155 0 STTNASTEH ISS 0 SMOT 44849 155 s3dnuJe ISS 0 40443 ISS 155 330 821 0000 0 PM Pwj 454 831 0000 0 wn3ed 40553 431 0000 0 13235 821 0 sSJOJJ3 421 SATTU S TIU EJI aJI gt gt gt gt gt gt PIOPEIZTPOGZTTO 0798 04830020 9 98 20 00 22 60 002 4340 AN 19 0 8000 otg geeoxo 6 TT 62TOxO 6 TT 0820x0 070 P080X0 otg 6880 0 88 0 0 4725 4725 BPPOX0 eppoxo ST ON ug 330 8000 0 6000 0 d 0 0 0 pexoorg RaTJeg 000 484 AS Sd 000 484 NSd 000 AZT 8 Sd 000 AcT Sd 000 6 a nsd 000 8 nsd 000 wwog dwaj 000 dal 000 NdINIT dwal 000 8 nsd dual 000 dwal prousaJu Pa3Je35 PTON 4 perqeu3
43. C 83 Invalid for this State c2 hex Swift User Manual Swift UVOT 302 R03 C 15 This verification failure message is issued the command with the indicated APID and Function Code is received when the is in a state for which the command is illegal see the Command Table appendix D 2 in Message Codes appendix for a list of the APIDs and Functions Codes and also the state table appendix D 8 for a list of states C 84 Invalid Length 05 hex This verification error message is issued when a command with the indicated APID and Function Code is received with the contents of the packet length field outside the valid range see the Command Table appendix D 2 in the Message Codes appendix for a list of the APIDs and Functions Codes P1 Contents of the packet length field P2 0 C 85 Limit Exceeded 91 hex This error message is issued when a limit is exceeded for n successive times An on board table described in appendix A 4 specifies n Item in hex for which the limit is exceeded see limit item table appendix D 11 in the Message Codes appendix P2 Value in hex that exceeded the limit The ICU response is detailed in both the Errors Action Table see appendix B 8 and the Limit Check table appendix A 4 the latter usually being to run the gotosafe RTS C 86 No Such UVOT AT Mode 44 hex This error message is issued when the ICU could not find a match in the Automated Target AT table for the
44. C Ris eee LOAN 1 WA Jomod 0 JU A NOK poxse 92U 330 xo pue 110 joan A JANAT Jomod oj JULM JooURD uo pue MOT yoyo pue 110 12846 pue v 4 jsqperodg LOAN I On WL Padd 0 i S VQ wer 65 oSed a8ed paramod ASI 1204 03 snp 10 390 ol Jou yosdD LOA MOT STSOTdA 351212245 LOAN uuojur 104 jsiperoodg AST And LOAN LOJ I MOT SMIS nor 32245 pue SooId 6 2 mios Ud e3es 2014 1015 pue Sues 9 LOAN seInpsoord AO 0J 21584 ol OD SALWLSMHOWT LOAN I poywodar 1881 03204455111 JOAN oy ssed Od allis NO 0 3Md9gDodDeygoTdds mu352s3oAn Fed st 45340 7 x 781912946 Ama LOAN WOJU
45. EEPROM Data Tables Action Tables and RTS tables Data Tables These contain sets of numbers that may need to change in the course of the mission These include calibration data for the on board high voltage ramping and heater control algorithms Two further tables contain the and PT exposure configurations Count rate and avoidance angle tables are also present and are more fully described in the On Board Catalogue section Action tables They define actions that are to take place when an event or combination of on board values occurs Those actions are defined by declaring a Relative Time Sequence RTS see below to be run They consist of a Astate change table the usage of which is described in the UVOT State Transitions section below b A limit checking table that states which RTS is to be run when a limit failure for a particular engineering item occurs see below for a fuller description Swift User Manual Swift UVOT 302 R03 26 c errors action table that states which RTS is to be run to perform an error recovery action All telemetry from the ICU and DPU is internally monitored for error messages When one is detected the table is then consulted and if required the appropriate RTS is run The design allows for up to 256 such messages RTS Images These are sequences of command words derived from text files containing scripts known as Relative Time Sequences RTSs There are in fact two types The first type contains
46. Hz a cruise speed of 420 Hz and an acceleration of 2000 Hz per second These rates are applied when moving from filter to filter or from datum to filter However in order to ensure success when seeking datum the filter wheel is rotated at a constant 200 Hz until the coarse sensor is detected and then at 10 Hz until the fine sensor is seen Points to Note filter wheel is a limited lifetime item it has been designed and tested for 50 000 complete rotations for each redundant half of the instrument Swift User Manual Swift UVOT 302 R03 19 filter wheel movement is controlled via the ICB This is also the main channel for acquiring housekeeping and controlling heaters It was found during testing that activity on the ICB during a filter wheel movement could introduce erratic motion of the filter wheel and cause occasional failure in reading the fine sensor Therefore whilst the filter wheel is being moved all other ICB activity such a housekeeping acquisition and heater control is stopped e Commands are sent internally to disable the flood LEDs see below prior to any filter wheel movement should they have been left on accidentally after e g a calibration exposure to prevent an illumination excess on the detector The safety circuit section Error Reference source not found is also disabled to prevent false triggering 1 2 3 1 1 Filter Responses 120 100 60 404 Effec
47. LED s In order that the detector may be calibrated in flight four flood LED s are provided They are located off axis close to the detector They are positioned so that their focused emission falls on the side of the filter facing the detector The blank filter is used which then acts as a defocused screen providing the flat field They are green LED s but with emission in the UV range Their intensity is controlled via ICB commands routed from the Blue Detector analogue control card to a 4 bit port There are thus 16 possible levels They are driven in such a way that if one should fail the remaining LED s will remain fully functional 1 2 5 Heaters and Thermistors There are 8 thermistors named and located as follows 0 Blue Processing Electronics co CC i THER EN RI NT M eno Esc ANGE TQ EPACE i G D Ranae don nuns Be n rus PE i 1 eg Lear BL a 5 ae TD WIA an SF 7 VENT AT WITH DIRECT S RERAMA BAFFLE ENTRANCE wi When the is in its nominal operating mode the telescope mounting flange is required to be 19 5 0 5 C in order to minimize the heat transfer between the TM and the Optical Bench and the mirror section of the telescope must be held at 19 5 1 5 to main
48. M4 71 ye z ovr 442 4 Net sg on A 9 VE Stel Lvs SIMI vad b fM B 22491 43 rw BMI M BMI Aa ug Pi catia a pj t 4 A 4 1 52782 Were iam TenueJNA 1950 IMS IEZA 3 4 CX P 7083 nz reer Wa 4 Rx VHC mL ke Aw oz 1 uc 6 11 t 1144 AYO l A 473 EXCA Be ih iu ov oe 95 Ts p HE 24 pr POTIS 329933 a DES gt XI 24 H Sca at 24 22 3 09 NC Dodge b 0 1 1 araea AFW KA TU CR CX Mp mv ix va SERO ks 1 RS Um Sueco ets bith tee 12 7 Dit baal 8 9 sew ven n 3025 quw sae 4 2 rfe 5 wry a
49. TMax Vdrop Specifies the upper value of the allowed temperature in raw thermistor i e uncalibrated units NumThermistors Specifies how many thermistors are to be polled An average of those thermistor readings is then calculated and compared against the values given by TMin_VNom and TMax_VDrop It can take the range 1 gt 3 If its value is one then the thermistor number given by Therm1 will be used If its value is two then the average of the thermistors specified by Therm1 and Therm2 will be used etc Therml Thermistors to be polled The code numbers used are as follows Therm2 Channel Description 0 BPE Therm 1 Reference B 2 Reference C 3 Main 4 Forward 1 5 Forward 2 6 CCD T Reference A A 2 3 Focussing Swift User Manual Swift UVOT 302 R03 A 2 METERING_RODS and SECONDARY MIRROR are the focussing heaters The parameters described below state the nominal length of time the specified heater should be on within a fixed cycle time this is referred to as the duty cycle OnTime Specifies the nominal on time within the cycle Units are 1 10 second A value of zero disables that heater NOTE no more than one of the focussing heaters should be enabled If both are enabled the algorithm ignores the SECONDARY_MIRROR heater parameters CycleTime Specifies the cycle time Units are 1 10 second However the power actually developed is a function of a potentially varying spacecraft voltage The algorithm therefore als
50. Table Load Aborted 6f hex This event message is issued as confirmation when a load window table command is stopped by command C 116 Window Table Load Failure 66 hex This error message is issued when a window table load fails This happens when there has been 1 MACSbus errors when writing or reading the table or 2 verification errors caused by a mismatch between what was found in the table and what was expected The ICU response is detailed in the Errors Action Table see appendix B 8 C 117 Window Table Load Okay 65 hex This event message is issued as confirmation when a load window table command has completed successfully C 118 XRTPOS Processing Status 56 hex If issued as an event message then the processing of XRTPOS record was nominal If issued as an error message then the processing was not optimal If there is no other error message detailing the nature of the problem e g XRT supplied RA and DEC are out of range then this indicates that the position supplied was outside the field of view and was ignored Description P1 Hex P2 Hex P3 Hex Event Message XRT Position XRT Position Radial distance in X Pixel Offset 2s compliment Y Pixel Offset 2s compliment minutes Swift User Manual Swift UVOT 302 R03 Appendix D Message Codes This appendix contains the tables of codes issued by the messages described in Appendix D 1 RTS TABLE The table is in numerical order RTS Number in hex RTS Name
51. TeregS AAOT SA ss X E x vuy Li x 2 pm ou sidnzojur YINI 155 mae JO JaquUINN 15 oy 01 204 joan ut em Y N MOTJAA ssed xou LOd poyoofar spueuruioo SdWON 1025 jsperoeds ANG LOAN s loeluoD I 32109984 jo Joquiny paroda 159 03 204 10an ut V N ssed xou 9 104 C eu Suda INDI ysteroods LOAN 3283409 104 I soSessoul JoquINN 1se oy 01 204 joan ut Nda 24 VIN ssed em PfI eu Cad SAWON INDI LOAN 3983409 104 I paroda 158 01 2014 JOAN Nad V N 5584 xeu 2104 souo WOUdAT IND 38S 351212245 LOAN 99 1991000 I 2815 Jo 1se oy 01 201 joan ut V N muy ssed xou sono WOUdAT IND
52. UVOT PT Mode 48 hex No Usable Filters in Config 4a hex Not at Predicted Position 4e hex Reducing Requested Exp Time 4b hex RTS Line Trace 77 hex Running Recovery RTS ff hex Safety Circuit Alert 5a hex SC1553 Dump Report SID d8 hex C1553 Read Error 8c hex C1553 Startup Error 89 hex SLEWABORT Received 59 hex SSI Error cl hex State Transition Complete 41 hex Switching RTS 76 hex Timesync Jump 25 hex Timesync Overflow 24 hex Timesync Too Big 21 hex Timesync Too Late 23 hex C 13 C 13 C 13 C 13 C 13 C 13 C 14 C 14 C 14 C 14 C 14 C 14 C 14 C 14 C 14 C 15 C 15 C 15 C 15 C 15 C 15 C 16 C 16 C 16 C 16 C 16 C 16 C 16 C 16 C 17 C 17 C 17 C 17 C 17 C 17 C 17 Swift User Manual Swift UVOT 302 R03 105 106 107 108 109 110 111 112 113 C 114 C 115 C 116 C 117 C 118 Timesync Too Long Since 22 hex Too Many Acc d Cts Report SID db hex Total Exposure Time Is Zero 55 hex Unacceptable Absolute Drift 4d hex Unacceptable Diff ntial Drift 4c hex Undefined State Transition 40 hex Unexpected IsSettled Flag Off 50 hex UVOT Mode Exhausted 49 hex Watchdog Reports a Task Hang ed hex Window Table Already Loaded 5f hex Window Table Load Aborted 6f hex Window Table Load Failure 66 hex Window Table Load Okay 65 hex XRTPOS Processing Status 56 hex Appendix D Message Codes D 1 D 2 3 4 D 5 D 6 D 7 D 8 D 9 D 10
53. Vcathode and the filter wheel is not in blocked Damage can be 1 Deterioration of the MCPs 2 Deterioration of the photocathode 3 UV polymerization of contamination on the optical surfaces and 4 Bright focused light heat on the optical surfaces NOTE It is important to realize that even when powered off it is still sensitive to damage by ultraviolet light and heat When preparing for a slew i e after receives a slew warning SISLEWW ARNING but before replies with a SACSLEWSAFEREPLY the cathode voltage is set to zero This reduces the gain of the detector considerably but assumes we are still obeying the pointing constraints i e not close to the Earth Sun amp Moon At this point the UVOT is in SLEW state which is not the same as SAFE state When there is a risk from these objects the UVOT a ramps down all three high voltages to zero and then b moves the filter wheel to its blocked position Operationally the important points are 1 Itis better to have the DEM powered on all the time it cannot be damaged by pointing light The DEM can then control the telescope module TM in particular the filter wheel and send back state of health data 2 Powering off the TM by switching the main power particularly when observing should only be done in extreme circumstances It is better to ramp up and down the high voltages slowly rather than ramping them quickly or simply switching them on or off
54. a problem 10 If UVOT receives a slew warning but the spacecraft does not start to slew UVOT determines this by monitoring the IS SETTLED flag in the ACS record within 30s we will normally go to safe anyway taking a little less than 3 min 11 If the ICU watchdog reboots it will check and make safe the high voltages and filter wheel ELEN We expect to go to SAFE state in three possible independent ways at three different levels of urgency The slowest would normally be used unless there is an emergency Swift User Manual Swift UVOT 302 R03 40 1 Normal istate safe wait 180 2 Fastsafe irtsrun rts 0x301 note this is in HEX wait 14 3 Emergency Safe irtsrun rts 3 wait 5 During each of the above waits the telescope is being made safer 1 e after 1 s of fastsafe things are pretty safe and after 6s things are even better and after 14s we re as safe as we can be Therefore even if there is not time to wait 3 minutes 14s or 5s it is still worth sending the command 2 2 Noise on HV measurements Note that due to the noise in the A D circuit of the HV of up to 5 raw units it is possible to see HV values on the display with this excursion around the commanded value Five raw units corresponds to a value of 2 5 13 and 49 volts for Vcathode Vmcpl and Vmcp23 respectively 2 3 UVOT Procedures This section gives background information of the consequences to the hardware and software of running each of the
55. approach an EEPROM tabulated damage limit it will shorten or even suppress the exposure accordingly See also SAA Interruptions section 1 3 11 8 below The ICU will transition to the Safe Pointing state when informed that the spacecraft is slewing to a safe pointing This is done by the OBSERVATION_NUM being in the range 1 gt 6 in the ACS record This type of exposure occurs when no automated or planned targets are available They are treated internally in a similar manner to PT exposures However an important difference is that it is not possible to perform the safety calculations that are Swift User Manual Swift UVOT 302 R03 36 normally carried out in the slew state until arriving at the pointing position as the target pointing information is not available until the spacecraft is settled If it is determined that there are bright sources present a transition to Idle will then occur 1 3 11 8 SAA Interruptions All of the above actions may be interrupted by the spacecraft entering the SAA When this happens any exposures in progress are cleanly shut down and the ICU transitions to the SAA state Vcathode off and Vmcp1 and Vmcp23 at 70 of nominal values Upon exiting from the SAA the ICU attempts to transition back to the state it was in prior to the interruption For PT and Safe Pointing exposures the remaining time of the exposure in progress is executed In the case of AT exposures the next one is selected in the manner descri
56. be possible to observe any source for longer than about 45 minutes at which time the satellite must slew to another source For sources at high elevation above the satellite orbital plane this maximum observing time is decreased falling to zero at 84 degrees The detector is susceptible to damage from sources such as stars or planets brighter than about 8 magnitude depending on their colour The ICU must monitor long exposures and ensure that the total accumulated counts on detector locations associated with a given source do not exceed a damage limit stored in EEPROM Because of the particle radiation present the instrument may have to be protected during passages through the South Atlantic Anomaly SAA These interruptions will occur two or three times in any twenty four hour period and each may last up to ten minutes This protection is achieved by ramping down the high voltages controlling the image intensifier Because of the above constraints the ICU design must e Allow for automated and planned observations to be interleaved Expect either type of exposure to be interrupted by pointing and SAA constraints e Make decisions on exit from interruptions on how to reconfigure the instrument and restart the exposure Swift User Manual Swift UVOT 302 R03 25 Permit the curtailing of all types of exposures to prevent detector damage 1 3 5 Available Information The following information is supplied to the ICU to enable it to de
57. block is terminated with a record of the following form that indicates the location of the next block Yord Description Offset p 0 Set to Ox7FFF to indicate it is a pointer block 1 Location of next block within the PT Configurations ID table 2 ALTERNATIVELY set to zero to indicate this is the last block Swift User Manual Swift UVOT 302 R03 B 17 B 10 Count Rate Table The contents of this table are estimated count rates for a magnitude 10 object as a function of filter number and colour index used by the star catalogue They are used by the UVOT ICU to calculate expected fluxes from known sources in the field of view such as catalogued stars and planets Count rate 100 for the Blocked filter for a colour index of 3 0 17 lt B V lt 0 11 Count rate 100 for the Blocked filter for a colour index of 4 0 11 lt B V lt 0 01 Count rate 100 for the Blocked filter for a colour index of 5 0 01 lt B V lt 0 15 Count rate 100 for the Blocked filter for a colour index of 6 0 15 lt B V lt 0 30 Count rate 100 for the Blocked filter for a colour index of 7 0 30 lt B V lt 0 44 Count rate 100 for the Blocked filter for a colour index of 8 0 44 lt B V lt 0 52 17 Count rate 100 for the Blocked filter for a colour index of 9 0 52 lt B V lt 0 63 Count rate 100 for the Blocked filter for a colour index of 10 0 63 lt B V lt 0 68 Count rate 100 for the Bl
58. causes the FW to not be moved the Cathode to remain down and no exposure to be taken 24 MSSL ECR 169 The AT exposure overhead is 3s and the science output would be better if this could be reduced This could be helped by removing the delays between safety circuit commands Most of the improvement can be gained by optimizing the disabling of the heaters to avoid unnecessary delay see NCR 95 See also ECR 178 Risk of not fixing This can lead to loss of science data It is significant for short exposures and at the start of a when a quick response is important F 25 MSSL ECR 178 The failsafe filter wheel stops and table load aborts should be dealt more efficiently This could be considered part of ECR 169 Suggested fix Add logic to only do the filter wheel stops and table load aborts if there is already a movement load in progress Impact of the fix to the ground ITOS None Risk of not fixing Time wasted before exposures 26 MSSL ECR 191 When the ICU calculates that there is no observing time left countrate budget is used up the ICU should lower the cathode and only move the filter wheel to blocked if there are still many predicted counts with the cathode down F 27 MSSL ECR 192 BAT filter wheel delay code can be removed There must still be a 0 7s delay for the heaters to turn off This is a optional modification to release code space for additional modifications F 28 MSSL ECR 194 Remove focus heater c
59. ends an upload For full details see ICD for ICU DPU Protocol for C 53 EEPROM Code Compare Error a7 hex This error message is issued when after writing data to EEPROM A and reading it back the two did not compare well word written P2 word read back that did not match C 54 EEPROM Star Cat Compare Error a8 hex This error message is issued that after writing data to EEPROM B and reading it back the two did not compare word written P2 word read back that didn t match C 55 EEPROM Write Error 88 hex This error message is issued when there is a lock or timeout error when writing to the EEPROM Error code P2 MID the memory identifier C 56 Exit from Safe Forbidden 52 hex This event message is issued when an attempt has been made to exit from the safe state after an error condition has occurred which makes it inadvisable to do so without first resetting the ICU The state change request will not be obeyed P1 Current State should be 1 see state table codes appendix D 8 in the Message codes appendix P2 Requested State see state table codes appendix D 8 in the Message codes appendix 0 57 Flood LEDs Turned Off 5d hex This error message is sent if the filter wheel is being moved and the flood led is at a non zero value The flood led is set to zero before the filter wheel is moved There are no associated parameters C 58 FONEXTOBSINF
60. filter wheel position is actually shown as blocked on the HK display when the state is shown as safe The procedure go on to power down the UVOT but the failure of the filter to achieve blocked should be brought to the attention of the UVOT team At the completion of the icu safe proc the proc then proceeds to power off the TM waits for any exposure still being processed by the DPU to complete and empty its telemetry queue ensures the s c no longer expects a response to a slew request from UVOT then powers down the DEM 2 3 4 2 Power On Procedure The uvot power on proc ensures that all the relevant UVOT pages are displayed the 1553 enabled for the ICU and DPU and the DEM started It then validates that the ICU is receiving telecommands from the spacecraft SISCATTITUDE and TIMETONE after power on before continuing with anything more A deliberate wait is then Swift User Manual Swift UVOT 302 R03 42 imposed in order to deal with NCRs 60 and 85 which relate when DPU HK may be considered valid The spacecraft is then told to expect acknowledgements from the ICU to any slew request The pages are then checked for validity so far before proceeding The TM is then powered and a second check of the pages performed At this point the ICU will be in Basic State The command to go to Safe state is then issued The 1PPS is enabled and the pages checked again After a suitable wait to allow for NCR 85 problem on board ICU limit violation checking i
61. how the UVOT proceeds around the state diagram during operation As mentioned above these transitions are handled by the appropriate RTS In particular once the state has reached Idle and we are fully enabled for observations the selection and running of the appropriate RTS to perform a given transition is performed autonomously 1 3 11 1 Turn On At turn on the UVOT enters the Basic State 1 3 11 2 Becoming Operational Upon receiving the ist ate command with the state set to Safe the ICU loads its operational code from EEPROM A into RAM executes it and transitions to the Safe state The instrument is in a safe condition and is not capable of performing observations 1 3 11 3 Preparing to Observe Upon receiving the ist ate command with the state set to Idle the ICU prepares the instrument for observing e g HVs are enabled and and Vmcp23 are ramped up to operational levels see section 1 2 2 4 the filter wheel in blocked and the BPE tables sections 1 2 2 6 2 and 1 2 2 6 3 loaded and will usually leave it in the Idle state It should be noted and as can be seen from the state diagram that it does this via the SAA state Should the spacecraft be within the SAA at the time of this transition the ICU will leave the UVOT in the SAA state with for instance Vmocpl and Vmcp23 at 70 of their operational values and will not complete the transition to Idle state until the SAA is exited The housekeeping display will refle
62. in EEPROM B which was correctly noticed by the flight software However the star catalogue count rate table and RTS index and table are not CRC checked every read but only at the start of a group of reads AT and PT configuration tables have the same problem but they are probably not a safety issue Since EEPROM bit errors have been observed at MSSL and elsewhere with a bit changing from 0 to 1 and back on a very short timescale these tables should all be read into RAM and CRC checked before the values are used and the values used should only be read out of RAM Suggested fix Change the Ada code to perform a running CRC until the required part of a table is found or cache the EEPROM and checksum each segment against stored checksums Impact of the fix to the ground ITOS Image changes and load procedure changes may be required 16 MSSL 110 Filter wheel position lost Operational Impact see procedure UVOT 12 F 17 MSSL NCH 117 There is an error in the star catalogue code which means that 2 very bright stars may not be avoided by the distance specified in the angular constraint table F 18 MSSL NCH 121 ISFTYSYSEN occasionally goes to 0 19 MSSL 125 Heater set command Vmin Vmax causes reboot F 20 MSSL NCR 129 When the observatory is in Safehold the ICU still checks against a Sun constraint angle of 30 when it should use a value of 20 an no constraint for the Earth and Moon This is because in th
63. in hex see RTS table appendix D 1 in the Message Codes appendix The ICU response is detailed in the Errors Action Table appendix B 8 C 31 DCS RTS Already Running 80 hex This event message is issued when an attempt is made to run an RTS that is already running The run request is ignored RTS number in hex see RTS table appendix D 1 in the message code appendix C 32 DCS Stack Exceeded 72 hex This error message is issued when the stack depth of the on board virtual machine that is used to execute RTS is exceeded The circumstances of the detection lead to different values of the parameters If P3 is zero then the condition was detected whilst the stack pointer was being increased If P3 is 1 then it was detected just prior to an attempt to place the current RTS argument number P2 out of a total of P3 on the stack The ICU response is detailed in the Errors Action Table appendix B 8 Swift User Manual Swift UVOT 302 R03 9 C 33 DCS Starting RTS 79 hex This event message is issued as an RTS defined by P1 see RTS table appendix D 1 in the Message Codes appendix starts P2 and P3 are set to zero C 34 DCS State Table Match Fail 7a hex This error message is issued when the ICU is unable to decide what autonomous transition is should perform There are no parameters associated with the message C 35 DCS Too Few RTS Arguments 85 hex This error message is returned if less than the expected numb
64. is achieved by synchronizing the pixel analysis to the frame sync signal issued at the start of each frame Video data When the safety circuit detects a bright High source it automatically powers down Fameslgnals mogge ee Unit the cathode voltage of the detector control This significantly reduces detector gain signal It also reports the alert signal in the safety circuit status register The ICU may then take extra safety actions the MCP bias voltages will be ramped down to OV and the filter wheel is moved to the blocked position For test purposes the cathode voltage control circuit may be disabled while still reporting the alert in the control Blue Processing Electronics Instrument Control Bus register The flow diagram below shows Safety Circuit the potential logical flow for each valid Connections to raw pixel read out from the camera BPE and Camera buffered data to the 1 2 2 5 2 Control interface DPU Two read write ICB sub addresses are used to control and monitor the safety circuit The controls signals are System enable This function enables the safety circuit When asserted the command is internally synchronized to the next IRUN signal allowing the system to start in a predictable manner Alert flag This read register signal indicates when the safety circuit has fired The cathode safe signal is asserted if the alert enable bit is set Swi
65. known as the BPE acquires and forwards photon events to the Data Processing Unit DPU in the Digital Electronics Module DEM The BPE also 1 controls the high voltage unit attached to the image intensifier 2 activates the calibration flood LEDs 3 powers to the filter wheel position sensor and 4 monitors the effect of the heaters via thermistors The Data Processing Unit DPU processes the photon events into lists images and a parameterized finding chart that are then forwarded directly to the spacecraft lt Telescope Module HEATERS THERMISTORS from 1553 BUS Redundant Power Side DATA Image Data and Control HIGH VOLTAGE Image Intensifier E PROCESSING UNIT Power DETECTOR BEAM TMPSU PROCESSING CAMERA 3 STEERING ELECTRONICS MIRROR and Data Ed Ed Fine FILTER WHEEL FILTER Position MOTOR WHEEL mal Coarse Position Sensor INSTRUMENT CONTROL Instrument UNIT Control Bus UVOT Electronic Architecture 1 3 2 Scientific Requirements In order to achieve the scientific goals of the UVOT the ICU must autonomously control the instrument to perform two types of exposure sequences automated and planned Automated these occur when Gamma Ray Bursts GRBs are detected by the Burst Alert Telescope BAT or a Target of Opportunity ToO is detected by other spacecraft and ground based sources On the first observation of the source an event list is gathered while the sp
66. not the same as Corrupted EEPROM Data That is caused by a CRC failure The ICU response is detailed in the Errors Action Table see appendix B 8 hex hex hex Swift User Manual Swift UVOT 302 R03 C 3 8 Value hex Several IEEE format numbers are supplied to the ICU via the spacecraft When converted into the internal floating point format used by the ICU and found to be out of the expected range this error message is issued Parameters p2 and p3 are always zero IEEE Number Description P1 hex ID ACS PACKET RA ACS PACKET DEC ACS PACKET ROLL ACS PACKET LATITUDE ACS PACKET LONGITUDE XRTPOS XRT RA XRTPOS XRT DEC ACS BUS VOLTAGE NEXTOBS NEXT RA NEXTOBS NEXT DEC NEXTOBS NEXT ROLL BATGRBFLUX PEAK The ICU response is detailed in the Errors Action Table see appendix B 8 9 BATGRBFLUXINFO Proc Stat 58 hex This message is issued as a major anomaly if no BATGRBFLUXINFO message is received from the BAT at the start of a burst or as an event message if that message is received The parameters summarize the result of the processing of the message P1 0 1 Not OK OK to proceed with the settling exposure respectively P2 0 1 Not OK OK to proceed with the finding chart exposure respectively P3 0 1 Proceed with normal exposure sequence Bright GRB exposure sequence respectively C 10 Boot Dump Report SID d9 hex This returns a memory dump of some key variables to assist in the diagnos
67. not deemed to be asleep This copy printed at 01 22 PM on 19 Apr 05 Swift User Manual Swift UVOT 302 R03 4 ICU A ICU B 1553 Addres P 15WayD S P _ cm p eae han nm Interface Connector Trans id M 4 1553 Interface 5 Chat B hie ChanB _ connector 4 4K x 16 N s gt 55 1024 16 Receive E PROM FIFO STAR CHART DCS 32K x 16 128K x 16 PROM SRAM CODE STORE ICU BACK PLANE KZ NZ Data amp Address Busses Data amp Address Busses gt lt Diagnostic 4 X ICB Interface ks 4 gt 1PPS gt gt Interface 15 WayD MA31750 d Watch Dog gt N Timer mA 1 PPS 12MHz 9 Way D S M 4 scillator Module 48 24 12 6 2 5 ICU Functional Block Bus Arbiter amp Power OK Diagram Cycle Protect 4 1 Circuit 01 02 01 MRH TBA including reference to switched round thermostats on DEM QAR 3442 1 1 3 Interfaces 1 1 3 1 1553 Interface All data includes commands housekeeping science data time distribution messages burst alert messages and inter instrument communications is passed to fr
68. of next data block for this Start of next block of configuration 467 UVOT Mode Set to zero if no more blocks available for this data for other UVOT Modes UVOT Mode 468 CRC of whole data block Swift User Manual Swift UVOT 302 R03 B 7 Configurations This table consists of a series of contiguous data blocks each of which contains a possible planned UVOT experiment configuration Note that they also include the finding chart or settling configurations The PT Configuration ID table see below is used to specify and point to which one or more of these configurations correspond to a particular UVOT mode The table below describes the content of each block Word Offset Description 0 Configuration ID simply a label not to be confused with the UVOT Mode 1 Exposure Time seconds 2 DPU Mode 3 DPU Sub mode 4 DPU Binning Level 5 Detector Acquisition Mode 6 Filter range 0 gt 10 7 DPU Image Window Origin X range 0 gt Ox7ff 8 DPU Image Window Origin Y range 0 gt Ox7ff 9 DPU Image Window Size X range 0 gt 0x800 10 DPU Image Window Size Y range 0 gt 0x800 11 DPU Event Window Origin X range 0 gt Ox7ff 12 DPU Event Window Origin Y range 0 gt Ox7ff 13 DPU Event Window Size X range 0 gt 0x800 14 DPU Event Window Size Y range 0 gt 0x800 15 Detector Window Origin X Units 2 2 CCD Pixels range 0 gt 0x7f 16 Det
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70. produced each time a telecommand is received If this is during an ITOS load one will be produced every 1 3 s This will put stress on the ICU code and may possibly lead to a reboot 2 5 4 Heater Control Parameters Use of IHTRPARAMS This command is used to specify temporary heater control algorithm parameters 2 5 4 1 Overview Normally the behaviour of the heater control algorithm on UVOT is determined using parameters stored in an on board EEPROM table However for testing purposes it is useful to temporarily override some or all of these parameters without reloading the table The command iHtrParams provides this facility It is used as follows First disable the heater control algorithm iHtr Off Then send up to 4 3Ht rParams command 1 per heater to alter the appropriate parameters iHtrParams Number 1 re specify heater 1 parameters iHtrParams Number 2 re specify heater 2 parameters etc Then re enable the heater control algorithm iHtr On The algorithm will then run with the parameters just specified Any heater not re specified will continue to run with the previous values To force a reload of the parameters stored in EEPROM simply disable then re enable the algorithm i e iHtr Off iHtr On Swift User Manual Swift UVOT 302 R03 59 2 5 4 2 Parameter Description There are two types of heaters focussing and non focussing The parameters are used in a different fashion for each type Consequen
71. right ascension divisions the number depending on how the width of the field of view changes with respect to right ascension at each declination Declination Right Ascension Band Divisions 0 to 4 5 and 6 Within each declination band the right ascension divisions are numbered from 0 upwards starting at RA 0 0 degrees So for example sky area south 12 30 would be in the southern hemisphere in declination band 12 which extends from 51 degrees to 55 degrees 15 arc minute and right ascension division 30 which in this band extends from 200 degrees to 206 degrees 40 arc min Offsets Contains the offsets of the source from the origin of the sky area the first byte is the RA offset and the second is the declination offset Each sky area is subdivided into a 255 by 255 grid and every source assigned to its nearest grid point The RA and declination offsets stored in the catalogue are the coordinates of this grid point within the sky area counting from 0 to 254 in each axis Positional accuracy in the field of view in either axis is to half an arc minute or better at all times If the source is Uranus or Neptune then this value is always zero Swift User Manual Swift UVOT 302 R03 C 6 C 16 Centroid Table Already Loaded 5e hex This event message is issued when the parameters of a load centroid table command are the same as the on board record of what was last loaded The table load is therefore suppressed There are no parameters associat
72. say if upon B 7 dividing the code number of the RTS by NHASH the result is n Each item in a section describes RTS by detailing its code priority and address information The index starts with a header that points to the start of each section The detailed format of the file is described below Word Description of Contents Section Offset 0 Header Size NHASH 2 1 Offset to start of section 0 in this special case will always point to offset NHASH 2 2 Offset to start of section 1 Index Header and so on until NHASH Offset to start of section NHASH 1 HNASH 1 CRC for Header This is immediately followed by section 0 NHASH 2 Length in words of section 0 NWSECTION including itself and CRC at end of section This is then followed by NRTS groups of three words describing an RTS where NRTS NWSECTION 2 3 NHASH 3 Code for RTS belonging to section 0 NHASH 4 Priority for RTS Section 0 5 Address of RTS divided by 0x20 32 decimal because RTSs always start on a word boundary divisible by 32 and so on until NHASH NWSECTION 1 CRC for section 0 Then we start section NHASH NWSECTION 2 Length in words of section 1 Section 1 Remainder of section 1 Section 2 through and so on for NHASH sections until NHASH 1 End of index CRC for whole index End of Index Swift User Manual Swi
73. the start of the addendum Each pointer is two words long The first 44 pointers each locate the start of a block of pointers within the pointer table itself In turn each of those point to a sky area in a band of the same declination There are 2524 such pointers and 22 bands for each hemisphere Each band is 255 arc minute wide except for the polar which is 45 arc minute wide The bands run in order from the north band nearest the equator to the north polar band followed by the south band nearest the equator to the south polar band Each declination band is divided into a number of equal right ascension divisions the number depending on how the width of the field of view changes with respect to right ascension at each declination as per the table below The sky areas run along the declination bands in increasing order of RA These are followed by a pointer to the start of the addendum The last entry in the pointer table is a one word CRC value The number of areas in each declination band is shown in the following table Band Number of Divisions Band Number of Divisions 0 90 11 60 1 90 12 54 2 90 13 50 3 90 14 45 4 90 15 40 5 80 16 36 6 80 17 27 7 75 18 24 8 72 19 15 9 72 20 8 10 72 21 2 Swift User Manual Swift UVOT 302 R03 B 5 B 2 4 Star Catalogue The main catalogue is split into 2524 sky areas in 44 declination bands of 22 per
74. the translated versions of the RTS scripts and the second an index into them In addition to determine if there are known bright sources close to or in the field of view a planetary position calculations are performed and b an on board star catalogue is checked There is an NCR outstanding on the EEPROM tables see Appendix F MSSL NCR 94 In theory it is possible for a CRC error on these tables to not be immediately detected as the CRC check is not performed every possible read to memory limitation issues In flight so far this does not appear to have been the case 1 3 7 1 Useful Numbers in EEPROM The following angular avoidance constraints for bright objects are stored in EEPROM e 25 Mercury Venus Mars Jupiter Saturn and don t care for Uranus Neptune and Pluto e 44 degrees for the Sun Spacecraft avoids by 45 by 46 e 28 degrees for the Moon Spacecraft avoids by 30 TAKO by 32 we may soon change this to 14 deg Spacecraft avoids by 16 TAKO by 18 e 92 degrees for the Earth Spacecraft avoids by 94 TAKO by 99 note subtract 66 degrees to get avoidance from earth limb 25 for stars magnitude 1 4 gt 0 0 In addition if any star in the field of view would produce 200 000 count s or more as determined from the on board catalogue the exposure is abandoned At 200 000 count s the following stars would be just observable Filter Spectral Type Magnitude White 9 1 4 5 Whit
75. three Micro Channel Plates MCPs a phosphor screen tapered fiber optics and a CCD see Figure 6 The photocathode is optimized for the UV and blue wavelengths Although there are three separate MCPs MCP2 and are butted up against each other The CCD has 385 x 288 pixels 256 x 256 of which are usable for science observations Each pixel has a size of 4 x 4 arcsec on the sky affording 17 x 17 arcmin FOV The first MCP pore sizes 8 um with distances of 10 um between pore centers The second and third MCPs have pore sizes of 10 um with distances of 12 um between pore centers Photons arriving from the BSM enter the detector window and strike the photocathode Electrons discharged from the photocathode are then amplified by the first MCP creating an electron cloud This electron cloud is further amplified by the combined second and third MCPs creating a larger electron cloud This larger electron cloud then illuminates the phosphor screen The photons created from the phosphor screen then travel to the CCD via the fiber optics This combination of MCPs and CCD provides an amplification of 10 of the original signal The registering of photons is achieved by reading out the CCD at a high frame rate and calculating the photon splash s position by means of a centroiding algorithm The centroiding algorithm also affords a large format to the CCD by sub sampling each of the 256 x 256 CCD pixels into 8 x 8 virtual pixels thus providing
76. up safety circuit appropriately for observations 5 reset slew 1793 0 Sets up safety circuit appropriately for slewing slew to at 805 1000 Performs Slew to AT state transition slew to fc 804 1000 Performs Slew to Finding chart state transition slew to idle 810 1000 Performs Slew to Idle state transition slew to pt 806 1000 Performs Slew to PT state transition slew to safep 807 1000 Performs Slew to Safe Pointing state transition slew to settling 803 1000 Performs Slew to Settling state transition slewabort 21 1000 Processes SISLEW ABORT command c 49 0 Starts and exposure sets up BPU commands DPU starts events tells ICU to start counting events Test 32 0 Not used testmode 1281 0 Not used Swift User Manual Swift UVOT 302 R03 30 RTS Name Code Priority Description undefined 32767 0 Not used 1 3 83 RTS Statements A RTS may contain any of the following statements Any UVOT telecommand The arguments supplied may be constants references to the contents of standard memory locations or arguments given to the calling RTS A secondary table directly derived from the ITOS database contains the formatting information for constructing the command on board An RT to RT telecommand These are system to system commands for example the UVOT after receiving a request to slew acknowledges to the spacecraft that it is ready to slew using the SACSLEWSAFEREPLY message A call to anot
77. will remain at maximum voltage as set within the HVU It should be noted that this condition produces excessive noise on all outputs and so the HVU should not be operated in this condition If this condition does arise it is necessary to command the voltage below maximum in order to regain control The voltage drop required is dependent on the particular MCP limiting and is shown in table 1 To operate the intensifier mcp23 is first raised to the desired operating voltage over a period defined by the rise time outlined above V anode Will rise simultaneously with Vincp23 such that Vanode 1 57 Vincp23 The voltage Vmcpl will not be allowed to rise until Vincp23 is greater than 1100 volts both intensifiers Once Vincp23 is above this level Vmepl be raised to the desired operating voltage and is again rate of rise limited For redundant intensifier the voltage across must be greater than 518 volts before Veathode is allowed to rise and will cause Veathode to collapse if less than 505 volts For the prime intensifier these restrictions are not incorporated into the hardware As before the rate of voltage rise and decay for 1 should be limited as outlined above The cathode voltage V cathode is then raised to the desired operating level to effectively switch on the intensifier To close down the intensifier the above procedure is reversed i e Veathode 1S set to zero volts then Vmcpl and V mcp23 V anode Both 1 and Vincp23
78. 06 lt 4 42 5 Y 100p WL LOAN durer LOAN TLHO06SdVaOWS 9 0OT 9 MOTO 9 i SH Ad Me 8 erz 0 LCOE LOA 1MIAS Tenuen SN 31A S Swift User Manual Swift UVOT 302 R03 58 2 5 Special Operations 2 5 1 How to Override Table Values in Ram The working copies of certain EEPROM tables are located at fixed locations in RAM It is therefore possible to change locations in these tables on the fly using the iicuload command This is useful if you wish to temporarily change standard operation as a workaround of a problem until the table can be properly reloaded These tables are the Errors Action Table appendix B 8 the Avoidance Angle Table appendix B 11 and the Standard Table appendix B 13 Those appendices should be consulted for details of how to change the values 2 5 2 Dumping or CRC Checking Memory when Observing It is possible to dump or CRC memory check areas of EEPROM when observing However it should be noted that if a telecommand arrives at just the time that an RTS is reading the information from that table in EEPROM a harmless 0x371 busy message will be issued and that particular dump or CRC won t work Note When a memory dump or CRC is critical such as after a code load we should and do stay in safe 2 5 3 Loading or Dumping Memory at the Same Time You should not do this The error message Busy will be
79. 1 3 2 Serial Synchronous Interface SSI The SSI is a bi directional communications interface between the DPU and ICU Both the ICU and the DPU can send and receive data on this interface but the ICU is the master Commands are sent from the ICU to the DPU DPU responses are sent to the ICU They are in data blocks identical in format to spacecraft packets A receive FIFO is included in the design in order to offload processing overhead from the ICU The SSI clock frequency is 125 kHz producing a period of 8 us 1 bit period The SSI 16 bit data words are separated by at least one bit period and at most the SSI block gap The SSI data blocks are separated by at least the SSI block gap defined in software For full details of the ICU DPU protocol on this interface refer to ICD for the ICU DPU protocol for the 03691 DPUICD 01 1 1 3 3 Instrument Control Bus ICB The ICU controls and monitors the telescope module via the ICB The ICB is the digital data highway that the ICU uses to send and receive commands and status An existing standard has been adopted for the ICB called the MACS bus Modular Attitude Control Systems bus detailed in the MACS Handbook prepared by MATRA for ESA It is a prioritized multi master bus Blue 1 Blue 2 TMPSU1 4 S 7 iN M J ICU 1 ICU 1 Because there are a number of units on the bus the ICB has several functions The detail of the fun
80. 101 Ramps HVs down to SAA levels ide noda 33 1 Sends DPU mode command and performs verification as described in the ICD for ICU DPU protocol Swift User Manual Swift UVOT 302 R03 29 RTS Name Code Priority Description Interrupts current exposure send stop command to DPU interrupt_exp 51 0 stops events to DPU tells ICU to stop counts received calculation line 1 0 Diagnostic not used noaction 0 0 The RTS equivalent of a command does nothing notallowed 32766 0 Reserved for ICU internal use 1018 1000 Performs transition to Idle state from AT PT Finding Settling and Safe Pointing states meds 20 32768 Processes SISLEWWARNING sends SISLEWWARNING PEN after Vcathode 0 then optionally calls do slew pt to pt 870 1000 Performs multiple PT exposures until next slew In the event of a filter wheel movement failure attempts retry fw 1282 0 recovery by going to datum then trying again or goes to Safe state if fails again saa to idle 906 1000 Performs SAA to Idle state transition safe t debe 794 1001 Performs Safe to Idle state transition note may stop in SAA state if spacecraft is in the SAA safep_to_safep 887 1000 Not used send_slewsafe 994 0 Sends SACSLEWSAFEREPLY to spacecraft settling to fc 820 1000 Performs Settling to Finding Chart state transition sfty reset 1794 0 Sets
81. 38W sqereds LOAN em 1981000 LOA T paroda 158 01 2014 104n V N ssed SIONI INO 35112245 LOAN 12809 I 28 Jo 15 oy 01 202 joan ut VIN s ssed em LOA soo IND 38W WVugd sqereds LOAN em 198109 LOA 1 poy uonoy 5 1951 IIMS LS LOAN 2 LAX 129 334 ECC SHOlHdHdoVS 84 84 LOAN 9U CALA SIojeog yosUo LOA 401 CALA CHO 11 206 lt 4 842 5 S ZHOludHOVS LI GI IIHO06SQVHOVS 8 WAA LOAN LOAN GTHOO6SdVHOVS pT 4 3 I WAC LOAN LOAN bp IHO06SQVHOVS 5108195 Aqivau yosdD LOd LAV INL LOAN LOAN 2064 2 5 9 71 WL LOAN due LOAN lt 20
82. 39 Reserved for Catalogue additions currently empty Unused 6F39D 802FF Comand Database 80300 80AFF Derived from ITOS Database used by RTS scripts to generate ICU internal commands RTS Index 80B00 80CFF Hash based Index into RTS Library see next item RTS Database 80D00 8214F Compiled Library of RTS Scripts Unused 82150 E30FF AT Configurations E3100 E7OFF Automated target configurations selected from using UVOT mode Planned Target configurations includes Calibration EH Engineering Settling Finding Chart and Safe Pointing Errors Action Table F8280 F82FF Action e g RTS called TDRSS message in the event of an error Specifies combination of PT configurations PT Configuration ID Table F8300 FF37F correspond to a particular UVOT Mode Count Rate Table FF380 FF4FF Count rate table as function of colour and filter used with catalogue to calculate maximum exposure time Avoidance Angle Table FF500 FF5FF Avoidance angles for Earth Sun Moon Planets and Bright Stars State Change Table FF600 FFEFF Specifies conditions for autonomous state changes Unused FFF7F Standard Table FFF80 Miscellaneous configuration specification items that do not fit into the above categories Swift User Manual Swift UVOT 302 R03 B 2 B 2 Swift Catalogue B 2 1 Catalogue Compilation The Swift catalogue was compiled from four catalogues Tycho 2 GVCS HI NGC and the Yale Bright Star Catalogue All cat
83. 4 phases 1 2 3 and 4 a clockwise rotor drive viewed from the shaft end towards the redundant detector is achieved by stepping in a positive direction e g the phases are energized in the order 1 2 3 4 1 until the step count is equal to or greater than 31 and the phase is 1 Similarly a counter clockwise rotor drive towards the primary detector is achieved by stepping in a negative direction e g the phases are energized in the order 4 3 2 1 4 until the step count is equal to or greater than 31 and the phase is 2 1 2 3 3 The Motor Temperature Control Circuit DISMON The DISMON circuit was included in the SWIFT TMPSU design to protect against the Filter Wheel and Dichroic motor windings being left on for an indefinite time and risk overheating the motors For example when a motor is being moved the software gets an SEU and a motor winding is left energized This circuit was not in the heritage instrument XMM OM design There are two circuits one for each motor The circuits compare a thermistor on the sidewall of the TMPSU with thermistors on each of the ballast resistors in series with the motors These ballast resistors are also on the sidewall of the TMPSU When a winding is turned on heat is dissipated in the ballast resistors so the temperature rises When the temperature difference gets to a certain value the circuit trips and clears the register that is driving the motor windings This register controls both motors and the two temp
84. 55 CORRUPTED EEPROM match all gotosafe 58 BAD DATA IN EEPROM RTS NDX HDR ID h emergency safe 61 BAD DATA IN EEPROM CMD DTB ID h emergency safe 64 BAD DATA IN EEPROM HV CALIB ID noaction 67 BAD DATA IN EEPROM HV CALIB 2 ID gotosafe 70 BAD DATA IN EEPROM HEATER TABLE ID h basic 73 BAD DATA IN EEPROM LIMIT CHECK TABLE ID h basic 76 ACS_MISSING match all fastsafe 79 NO_SUCH_UVOT_MODE match_all noaction 82 NO_USABLE_FILTERS_IN_CONFIG match_all noaction 85 NO_SUCH_CONFIG match_all noaction 88 UNACCEPTABLE_OVERALL_DRIFT match all fastsafe 91 E UNACCEPTABLE DIFF DRIFT match all blocked failsafe 94 NOT AT PREDICTED POSITION match all gotosafe 97 UNEXPECTED IS SETTLED FLAG OFF match all gotosafe 00 1 IMPOSSIBLE_STATE_TRANSITION match_all gotosafe 03 1 FORBIDDEN_STATE_RTS match_all gotosafe 06 ANGULAR_CONSTRAINT_VIOLATION match_all gotosafe 09 BRIGHT_OBJECT_PRESENT match_all noaction 12 SAFETY_CIRCUIT_ALERT match_all gotosafe 15 BAD_VALUE ACS_BUS_VOLTAGE gotosafe 18 BAD_VALUE ACS_PACKET_RA fastsafe 21 BAD_VALUE ACS_PACKET_DEC fastsafe 24 BAD_VALUE ACS_PACKET_ROLL fastsafe 27 BAD_VALUE ACS_PACKET_LATITUDE fastsafe 30 BAD_VALUE ACS_PACKET_LONGITUDE fastsafe 33 BAD_VALUE ACS_BUS_VOLTAGE gotosafe 36 BAD_VALUE NEXTOBS_NEXT_RA blocked_failsafe 39 BAD_VALUE NEXTOBS_NEXT_DEC blocked_failsafe 42 BAD_VALUE NEXTOBS_NEXT_ROLL blocked_failsafe 45 BAD_VALUE match_all noaction 48 TIMESYNC_JUMP match_all gotosafe 51 1 TIMESYNC_OVE
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87. AT exposure The following procedure is followed Ifthe intensity of is determined to be not bright then the data block list indexed by the value of Mode is searched If the intensity of the GRB is deemed bright then the data block list indexed by UVOT Mode 1 is searched linear search is then performed of the selected list starting at the last location accessed within that list for the current pointing until the a data block is found for which the actual time since burst is less than or equal to the tabulated time since burst Each block contains appropriate experiment configurations for when an XRT position was supplied and for each filter except blocked The next filter on the filter wheel from that used in the last AT exposure is normally selected However if the maximum exposure time specified in the table is zero then it is skipped If the tabulated minimum exposure time was not obtained in the previous exposure the filter used will be re selected and the exposure re started Word Description Offset 0 UVOT Mode Range 0x8000 gt OxFFFE 1 Time Since Burst seconds 2 3 Unused 4 Followed immediately by the configuration for Filter 1 Grism1 without XRT position supplied 5 Minimum Exposure Time seconds 6 Exposure Time seconds 7 DPU Mode 8 DPU Sub mode 9 DPU Binning Level Swift User Manual Swift UVOT 302 R03 B 10
88. E TABLE The magnitude code stored on board in the catalogue is derived from the visual magnitude Johnson V magnitude If V is lt 1 4 then the code is 0 From there on the magnitudes are gathered into bands each 0 1 of a magnitude wide numbered from 1 to 134 ascending So for example 1 3 gt V gt 1 4 has code 1 1 2 gt gt 1 3 2 11 9 gt V gt 11 8 has code 133 V gt 11 9 has code 134 Note no source fainter than V 12 0 is stored in the catalogue The following table gives this explicitly as a function on the magnitude code Magnitude Range E e ___ 0 ___ e ermer oaoa ___ 0 s gt Swift User Manual Magnitude Code Hex 35 Ra EA EN EN EA EN ES EA EN ES EN ES 2 gt ES EN Ed EN EN ES ES EA ES EN Swift UVOT 302 R03 Magnitude Range D 8 Swift User Manual Magnitude Code Swift UVOT 302 R03 Magnitude Range D 9 Swift User Manual Magnitude Code Hex ES ESI E Ea ES 5 ES ES ES EA ES ES ES
89. ECR 153 MSSL ECR 169 MSSL ECR 178 MSSL ECR 191 MSSL ECR 192 MSSL ECR 194 MSSL ECR 195 MSSL ECR 196 MSSL ECR 198 MSSL ECR 199 MSSL ECR 202 MSSL ECR 207 MSSL ECR 208 Swift UVOT 302 R03 4 4 4 4 4 4 4 4 4 4 4 4 F 5 F 5 F 5 F 5 F 5 F 5 F 5 F 5 F 5 F 5 F 6 F 6 F 6 F 6 F 6 F 6 F 6 F 6 F 7 F 7 F 7 F 7 F 7 Ss quepunpad ainpom ES 5 1000 lddns 4emod 101291 lddns 4emod adoosalel 904M 19914 9140419913 6ulsseoo4d 1012819q OA COE LOAN AIMS TenueJN 1961 1 46 A 4osuas uonisod 2 Sdd 89 iil sng 1044409 jueuinajsu 105 T33HM HOLON UOI ISOd 1 4 ould 90074 eled pue 539019 5 1 3318 40193130 Jede 6ulsseoo4d 35VL1IOA Ionuoo pue eled PES 219 6991 SYOLSIINYAHL SH3LV3H 1 Ne 27 J WUelo 104 uo 5 21u04129 3 LOAN HIMS EOA TOE LOANIJ MS enue A 125 YMS 1 Instrument Description 1 1 Digital Electronics Module DEM This controls a
90. HKON IHKRATE IHKTDRSS Swift UVOT 302 R03 IICBREAD IWATCHDOG IFWSETCOARSE IFWSETFINE IFWREL IDMSTOP IDMMOVE IHTROFF IHTRON IRTSKILL IHKOFF 4 Swift User Manual APID hex F C hex 660 or 670 660 or 67 95 660 or 67 660 or 67 660 or 67 660 or 670 al 660 or 670 661 or 671 661 or 671 01 662 67 N 662 or 67 N 662 or 67 N 662 or 67 662 or 67 01 662 67 N 01 662 or 67 N 02 662 or 672 03 665 or 67 665 or 675 01 66a or 67a 05 66a or 67a 66a or 67a 66a or 67a 66a or 67a 24 66a or 67a 40 66a or 67a 41 66a or 67a 42 N Command lois otis atl SP IBPESTOPCNTRDLD TLIMIT ILIMITOFF ILIMITON ITIMESYNC ISTATE ISTATETRANS IICULOADO IICULOAD IICULOADI IICULOAD3 IICUDUMP IICUDUMPABORT ITEST IDPUSTOP IDPUXRTPOS IDPUABORT IDPUPURGEDCX IDPUPURGESCI IDPUREBOOT Swift UVOT 302 R03 IDPUTASK ICHANGELIMITS IICUDUMP2 IICUCRC INHKECHO IDPUMODE IDPUNOOP D 5 Swift User Manual Swift UVOT 302 R03 D 3 TYPES OF FILTER WHEEL MOVEMENT Type of Movement we D 4 FILTER TABLE Note In HK and sequence print messages the value 2200 is used to represent Unknown Position and the value 2201 represents f w moving D 6 Swift User Manual Swift UVOT 302 R03 D 7 D 5 MAGNITUDE COD
91. I Jamod jou 3si eroedg ANG LOAN 8 188 pesn ST SYL X Sery pojqeuo ALH SU hae TA ic 1 ES pap 901 99 ol FI pexse UeUA JoouRD uo 730 31235 pue ompoooud 1 4 jou st PALL joan pue 3je1oooeds ou YIM Tesp SI 3je1oooeds J909 sey Fed 995 4 seu WL LOAN 99 OOD AOI J9u9uA LOAN 1 eges ages 3 oo 8104 1015 Sunnooxo eyes 31235 2014 1015 9 cdourA BOSNAE LOAN empooojd uyum 9519 94 LOAN uym 9519 pu 9 iecur MORD CAUA ampao MMH MOOT LOT T ayes auo3 erect 24 LOJ 45 LOAN 104 I sey LOAN 32943 onea dowy T 12995 FUT Jsqer2odg Sox AM LOAN 104 1 Pe eee MoMA MOI 2A post MOT Mog or
92. ICB interface for control of the above Note the detector processing electronics is often referred to as the Blue Processing Electronics BPE This refers to an earlier design of the heritage instrument XMM OM that also included a detector more sensitive to the red end of the spectrum The two detectors were labelled blue and red A block diagram of the detector electronics is given below 1 2 2 6 2 Window Bitmap RAM Before the detector processing electronics may be used the window bitmap RAM must be loaded The RAM is 64k by 4 bits The information loaded will cause only those CCD pixels within the desired windows to be readout i e a clocking sequence is generated for the desired camera format For every location on the CCD there is a location in RAM During row readout the corresponding RAM contents are interpreted as a window ID An ID in the range 1 to 15 is a valid window ID and the corresponding pixel pair is readout whereas a value of zero means that it is not in any window and will not be readout By loading up the RAM accordingly the detector area can be thus divided up into a collection of windows of varying size For full detector operation an ID if 1 is loaded into all locations Note that windows must start on an even number of CCD pixels in X and an odd number in Y However this even odd offset is added internally by the ICU software when loading the commanded tables The window commands specify their origins with re
93. IN SETTLED time out Issued by RTS blocked_tdrss after DPU_ACK time out via TDRSS EN Swift User Manual Swift UVOT 302 R03 0 11 LIMIT ITEM TABLE Item Description System Enabled hex in Basic wt Tere reser ue uu ee e as me Lar quee ___ vem Lu Temp PSU Mod A DEM via DPU Yes 88 1 Temp PSU DEM via DPU Yes ICU CPU Module DEM via DPU ICU Interface Module DEM via DPU DPU Comm Mem Module DEM via DPU Swift User Manual Swift UVOT 302 R03 Item Description System Enabled in Basic hex If 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d Alert Flag Safety Circuit Swift User Manual Swift UVOT 302 R03 D 12 TASK IDENTIFIER TABLE Task ID Task Description and Name hex Centroid Table Loader LOAD CENTROID TABLE D 13 HV CHANNEL CODE TABLE Swift User Manual Swift UVOT 302 R03 0 14 ICU ERROR EVENT CODES IN NUMERICAL ORDER Note turn to the next table for the error codes in alphabetical order Code hex o a wenmmimm Swift User Manual Swift UVOT 302 R03 Error Event Code hex DAT nT un CN NEA m Description Swift User Manual Swi
94. N LOAN SE rnp peou are suore SON LOAN WOFI 1 PPE a uo Jamod LOAN doa ees Suunp eurou 990N dum 1 de uora9es uo Jamod BN a NAE c M e Jon IE e Aou SgS gt TEM UOTIDeS go 330 joan 17816 220 qoan AS V NSd ees pue FUA 9 pue LOAN HO X 3 YASSnTdnddI An 3829465 Anq LOAN WOJU LO 1 MOTIF LOAN HO Imod 5 LOAN WOJU gt LOA I 635A6d jsqeroodg 10 LOAN Suunp Teuuou SUONLIOIA 93oN And LOAN LOA 1 ACI V 54 Jomod LOAN Suunp eurou SUONLIOTA Pur 9loN Bye pag d se3ou ees omod LOAN Suunp suone ora pur 9loN LOAN t aq eySnseAup LOAQ t yorym JOLIE LOAN oq yorym soSessour 9 83nseAU LOJ 10119 LOAN snosueInuurs opS3nso u Od pelIodar 85104 pores 1521 0 2044 5 joan ut jse 0 204d sjmuif ioan Ayed por ss
95. N SUT 514 3494473 0000 0 w434 0000x0 514 auoN 90 sponcns TOXO Spo 9T s3eaqjJ4eeH 297 Je3uno 529 555401 93 46443 14514 13614 WL og pool Ped 21 Poo9 IL 51399 Se eS oo pug 13235 300g 9 383236 550 LN UOT 3 40x0 orseg 342 625 Pid 4890 AM 342 bes Pid oTseg COU COE LOAN AIMS ALVLS 3375 3 ysy UAM 0Joz uou 80110591 uoos ATI ensn st ostou Aea uone nuis e 51 Joysdeus SI 220 AQ ou 97215 eUA 04 21215 FUTUOYISULI JJ 8 jou 9518994 51 91815 pue sJes ST 91215 JUALIN sueoui HTVS lt STVS SMOYS 5913 enue A 125 YMS X CX Tey nm 41 4 gt CX nz r ead cO IeMZeDel a atu E gt erie eI XX 4 WHC MAL XL ce sd Ro ke 4 e fw m i 114 Tel Fi i 47 2 K Sete J ed en ye amp A vr LIPS
96. O Processing Stat 57 hex If issued as an event message then the processing of the FONEXTOBSINFO record was nominal If issued as an error message then the processing was not optimal An additional error message detailing the nature of the problem e g supplied target RA and DEC are out of range will also be present Description Hex P2 Hex P3 Hex Event Message UVOT Mode 1 Is New At Slew Next Obs 0 1 10 AT PT IDLE Error Message N A N A N A Swift User Manual Swift UVOT 302 R03 C 12 C 59 Forbidden State RTS 42 hex This error message is issued when a state change command has been issued and the on board table of transitions described in appendix B 12 indicates that it is not allowed 1 Current State see state table codes appendix B 8 in the Message Codes appendix P2 Requested State see state table codes appendix B 8 in the Message Codes appendix 0 The ICU response is detailed in the Errors Action Table appendix B 8 C 60 FW at Requested Position 67 hex This event message is issued as confirmation that a Filter Wheel move was successful For additional information see the Filter Table in the Message Codes appendix Type of Filter Wheel movement requested see Types of FFW Movement table appendix D 3 in the Message Codes appendix P2 Number of steps just moved this may be shown as 0898 2200 decimal which actually means zero Current Filter Position
97. OM Star Cat Compare Error a6 hex EEPROM Write Error 88 hex Exit from Safe Forbidden 52 hex Flood LEDs Turned Off 5d hex FONEXTOBSINFO Processing Stat 57 hex Forbidden State RTS 42 hex FW at Requested Position 67 hex FW Lost Position 69 hex FW Move Aborted 6d hex FW Not at Blocked 6c hex FW Not Yet Datumed 6b hex HV Above Below Requested 11 hex Calibration Data Failure 14 hex HV Ramp Aborted 12 hex HV Ramp Failed 10 hex viii C 9 C 9 C 9 C 9 C 10 C 10 C 10 C 10 C 10 C 10 C 11 C 11 C 11 C 11 C 11 C 11 C 11 C 11 C 11 C 12 C 12 C 12 C 12 C 12 C 12 C 12 13 13 13 Swift User Manual Swift UVOT 302 R03 C 69 70 71 72 73 74 75 76 77 78 79 C 80 81 C 82 C 83 C 84 C 85 C 86 C 87 88 C 69 C 90 C 91 C 92 93 94 95 C 96 C 97 C 98 C 99 C 100 101 102 103 104 Ramp Succeeded 13 hex ICB Error b0 hex Errs Forced Htr Shut down hex ICU Watchdog Trip 90 hex Illegal APID 00 hex Illegal APID Length 0e hex Illegal Function Code 08 hex Illegal Memory APID 0d hex Illegal MID 0b hex Illegal Parameter Values 04 hex Illegal Start Address 0c hex Illegal State 0a hex Impossible State Transition 43 hex Incorrect Checksum 01 hex Invalid for this State c2 hex Invalid Length 05 hex Limit Exceeded 91 hex No Such UVOT AT Mode 44 hex No Such
98. Power Off The uvot_poweron proc see section 2 3 4 2 is run prior to running the icu idle proc as above 2 3 6 UVOT 06 Safing and Recovery During normal operations occasionally the UVOT may need to be placed into its Safe state for a number of reasons and then back to normal operations The proc icu safe is first run to ensure the is in a safe state see its description in section 2 3 4 1 After obtaining approval to return to normal operations the icu idle proc see section 2 3 5 1 is run to return the ICU to idle as thus capable of performing observations 2 3 7 UVOT 07 Recovery from Safety Circuit Trip The UVOT has a safety circuit that trips when the UVOT views an unexpectedly bright source as calculated from the ICU s star catalogue The trip of this circuit should generate a TDRSS message sent to the ground and will show up as a Red Limit for the mnemonic ISFTYALERTFLAG on page ihk The resetting of this circuit should not be done until the source is determined and verified that it is not going to be viewed again The procedure runs the icu idle proc as already described in section 2 3 5 1 2 3 8 UVOT 08 Observing Proc List This lists the STOL procs available for managing the UVOT observing activities This list is provided for informational purposes These procs should only be run under direction from the UVOT subsystem engineer 2 3 9 UVOT 09 Utility Proc List This lists the STOL procs available for commandin
99. RF LOW match all gotosafe 54 TIMESYNC TOOLATE match all gotosafe 57 TIMESYNC_TOOLONGSINCE match_all gotosafe 60 1 TIMESYNC_TOOBIG match all gotosafe 63 1 C1553 READ ERROR match all gotosafe 66 FW_LOST_POSITION match_all noaction 69 DM_LOST_POSITION match_all noaction 72 DPU_TIMEOUT match all noaction 75 DPU_NAK match_all noaction 78 DPU_INCORRECT_ACK match_all noaction 81 DPU_INVALID_APID_OR_ID match_all noaction 84 DPU_INCONSISTENT_APID_ID match all noaction 87 SSI_ERROR match_all noaction 90 WINDOW_TABLE_LOAD_FATLURE match_all noaction 93 CENTROID_TABLE_LOAD_FATLURE match_all noaction 96 1 HV RAMP FAILED match all noaction 99 ADA_EXCEPTION match_all h_basic 202 LIMIT_EXCEEDED match_all noaction Swift User Manual Swift UVOT 302 R03 B 15 Record N s T NHK Error Code NHK Parameter Match RTS to run Offset 205 1 1 1 DCS_STACK_EXCEEDED match_all gotosafe 208 1 1 1 DCS_INVALID_COMMAND_TOKEN match_all h_emergency_safe 211 1 1 1 DCS_INVALID_EXEC_TOKEN match_all h_emergency_safe 214 1 1 1 DCS_INVALID_POKE_OFFSET Match_all h_emergency_safe 217 1 1 1 DCS_CALL_DEPTH_EXCEEDED match_all gotosafe 220 ih 1 DCS_NO_SUCH_RTS match_all noaction Swift User Manual Swift UVOT 302 R03 B 16 B 9 PT Configuration ID Table This table is used to derive the sequence of exposures to which the UVOT Mode supplied in the FONEXTOBSINFO corresponds It consists of a s
100. S 31235 2014 Ain 6 e1npoooud MOT OJ Udy o3es 20141016 Suyes 9 LOAN 21884 oloD 104 BN LOAN 7 4 S9SfTId0nS qdNL NA 99 juaum rey GNA sq Jomod NOK jr usu 19208 VAS ASAIN YSSATANSANL 01 JULM NOK JI poyse eoueD UO Ho ono pie JJO AOS JoAN juoxm ey gt yoo pue 120 joan pue AR Agz empoooid PLL juoxm quoil NAH dae ispereds LOAN I 0 AST ASAI 5 98ed 4 puse LAN juoum a8ed 4 Il1S014nSdWl 8 ALL ol JOU 42940 LOA Gren 0u ELO 2 ASdWL 51212245 LOAN 71 yuno WGSOANIWNS AMG LOAN 104071 YAS ae juoxm AST GTSONIWOS poywodar 15 0 2024 JOAN ur oy ssed Od
101. S would switch to an alternate RTS that will return the UVOT to the safe state The centroid and window tables are then loaded with their EEPROM tabulated values In each case a verification of the contents is performed and if necessary a second attempt is performed This would lead to Centroid Table Load Swift User Manual Swift UVOT 302 R03 43 Failure and associated DCS Event Time out messages Should either load fail after the second attempt the RTS would switch to an alternate RTS that will return the UVOT to the safe state The camera is then enabled and flags set that enable autonomous transitions to the AT PT or Safe Pointing states should we now be interrupted by a slew The RTS now drops its priority to normal level sets the state to SAA and then providing we are not in the SAA performs the final ramping of the HVs with the exception of Vcathode which remains at zero to their operational values Again any failure of this latter operation would lead to a return to safe state 2 3 5 2 Recovery from TM only Power Off The uvot tm recovery proc is run prior to running the icu idle proc as above This ensures that the TM is powered and the ICU is in Idle state It is worth noting that because the TM has been power cycled but the ICU has not an ICU internal flag indicates the BPU tables are already loaded but the RAM of the TM BPE has been cleared Therefore this procedure reloads those tables 2 3 5 3 Recovery from UVOT
102. SWIFT UVOT 302 R03 Date Original Submitted July 7 2004 Prepared by Howard Huckle Date Revised 19 Apr 2005 Revision 03 Revised by H E Huckle Pages Changed See Revision Summary Comments See Revision Summary SWIFT UVOT USERS GUIDE Reviewed by Date FOT Harry Anderson MSSL SW Engineer Phil Smith MOC Deputy Director Marg Chester Flight Ops Lead Mark Hilliard UVOT Electrical Systems Engineer Barry Hancock NFI QA Manager Shane Lanzendorfer This copy printed at 01 22 PM on 19 Apr 05 Swift User Manual Approved by Swift UVOT 302 R03 Director John Nousek Mission Ops Manager Lou Parkinson UVOT Lead Pete Roming Date Swift User Manual RELEASE Swift UVOT 302 R03 REVISION SUMMARY BRIEF DESCRIPTION REASON FOR CHANGE iii EFFECTED PAGES 08 Sep 2004 26 Nov 2004 19 Apr 2005 Cross references added to aid information access Added section on DISMON circuit Added some additional special operations Added additional safety issue points Some typos found and corrected Text clarity improved Some addresses corrected Added description of pseudo sources to catalogue section Added DPU response matrix Added ICU response matrix Added filter responses Major revisions to limit violation table Revised image intensifier diagram Clarified many ICU SOFTWARE section items Modified AT PT Standard and Er
103. Time signal indicator but too long Broadcast received S c attitude and slew status info Notification s c has aborted slew Notification s c is about to slew Time signal indicator XRT centroiding error info E 3 Swift User Manual Swift UVOT 302 R03 F 4 Appendix ICU software NCRs and ECRs This is a summary of MSSL UVOT ICU NCRs ECRs and open issues as of release 10 of the ICU code The official and original documents are available from MSSL PSU and GSFC QA F 1 Goddard NCR SWIFT2002103006 During UVOT Thermal Balance the survival heaters were not able to maintain the detectors at their desired survival temperatures F 2 Goddard NCR SWIFT2002103007 During Thermal Balance the UVOT Door Module approach its survival operational temperature prior to the cold sink temperature being reached It appeared the door would exceed the survival temperature if the space enclosure plate was allowed to continue go to its sink temperature Space plate was at 45 degrees C required temperature was to be at 106 degrees C Door temperature operational limit 35 degree C survival 45 degree C F 3 Goddard NCR SWIFT20021 12002 Twice today the DPU ended an exposure prematurely Both exposures were run under conditions in which the TMALI queue in the DPU was filling from time to time 4 MSSL NCR 22 Basic Code If after a reboot the limit checking is commanded off 1imit off before it is started automatically and is then commanded off agai
104. Wanode decay rates are limited but Veathode be commanded to zero instantly if required Note that for the prime intensifier cathode iS limited to 530 volts and for the redundant intensifier V cathode 1S limited to 400 volts Voltage Converter 3 Multiplier Signal Image Intensifier Tube Vmcp23 Control Signal Vcathode Control Signal Converter 1 Swift User Manual Swift UVOT 302 R03 11 1 2 2 4 Image Intensifier Photocathode Ground Vcathode 1 MCP front Vmop1 MCP1 MCP middle Vmcp23 MCP2 MCP back Vanode 3 Vmcp23 a Anode Straight fibre optic bundle Phosphor Fibre optic taper 3 37 1 CCD 385 x 288 1 2 2 5 Detector Safety Circuit 1 2 2 5 1 Overview If exposed to bright sources the UVOT detectors may be temporarily or permanently degraded The main effects are 1 Fluorescence phosphorescence This is a temporal effect If a 5 6mag AO star illuminates the detector through the white filter for one minute then its phosphorescence remains above detection limits 0 008 counts s for 16 hours Swift User Manual Swift UVOT 302 R03 12 2 MCP gain loss and photocathode damage This results in permanent performance degradation due to a localized gain loss in the MCP and a loss in sensitivity of the photocathode due to ion feedback from MCP pores The UVOT safety circuit protects the detector against unexpected
105. acecraft is still settling on the target An exposure is then made from which a finding chart is constructed to permit optical counterpart identification All subsequent exposures on this source for this and later slews to the same source will involve obtaining a sequence of images event lists or combinations thereof in differing filters with increasing exposure lengths The active area used on the detector referred to as the window will be refined if the X Ray Telescope XRT is able to supply an improved position before the end of the finding chart exposure Swift User Manual Swift UVOT 302 R03 24 Planned this series of exposures obtains images event lists or combinations thereof They are in various instrument configurations loaded in on board electrically erasable programmable read only memory EEPROM tables and selected by an up linked plan 1 3 3 Engineering Requirements The ICU must respond to pointing constraints imposed by the Sun Earth Moon and planets Whilst observing a source the ICU avoids damage to the instrument from known bright sources in or close to the field of view FOV These can cause irreparable damage to the UVOT instrument by depressing the gain of the Micro Channel Plates MCPs or by damaging the photo cathode Note additional hardware protection against unknown bright sources is provided by the safety circuit described above in section 1 2 2 5 The ICU needs to monitor critical parameters for out of lim
106. ad Install Patch TBA WAAHI d nsd durs VSd SHI V dural WAAHI IMPON NOI WHHHI IMPON NOI durer WOS odv 444 AGd JOU AS NSd AS V 4 V sselIoA LANA Aed 444 AGW JOU AS ATI V 3 Aq 4 pue ISS NOI 943 aues Aq Aq uodrosed SMOYS o eq sf qe l Kay Jey 0 ST Yons sy syed LOAN jnq IUS Jo 5 j2vj
107. ally be determined in open loop mode by step counting from a known datum position Coarse and fine position sensors are provided to relocate the datum position should it be lost verify the wheel position during and after every rotation and to confirm that the centre of any optical element has been found although the element is not identified The reflective infrared coarse position sensor is fitted to the wheel and gives a true output when the wheel is within about 15 of the datum position i e the coarse sensor is only visible when the blocked datum position is in the field of view and typically for 90 steps around that position The infrared fine position sensor which is used in transmissive mode is fitted to the rear end of the motor An occulting disk with a small aperture through which the sensor looks is fitted to the rear extension of the motor shaft Itis aligned such that an element will be correctly positioned when the fine sensor gives a true reading and the first phase is energized Thus the fine sensor is only visible for one step in every 200 steps i e at the centre of the datum blocked position and at the centre of every other of the 10 optical element positions One step either side and the fine sensor cannot be seen Therefore it is only at the datum position that both the coarse and fine sensors give a true output see table above Tests indicated that the filter wheel should be rotated at a default pull in speed of 200
108. ally precludes a safe observation as the maximum safe exposure length is then set to zero number of stars found so far in the target field of view at the time the condition was detected P2 the maximum number of stars allowed in the working copy this should be one less than P1 P3 the current UVOT Mode C 14 Busy 82 hex This verification failure message is issued when a command has been rejected because an on board process is still busy performing an earlier command In this case the 2 parameters associated with this type of message are always set to zero However the TC APID and TC Function Code also given in the message specify which process was still busy TC APID TC Comments hex Function Code hex 660 or 670 The BPE centroid table loading task is still loading 660 or 670 The BPE window table loading task is still loading Note an APID in the range 670 to 67f hex indicates that the command was issued on board from an RTS C 15 Catalogue Star dc hex This message is issued to indicate that the predicted field of view according to the on board catalogue has the described source located in it The format of this message is non standard The fields are described below RA the source s RA expressed and rounded up to the nearest minute of arc hex Dec the source s DEC 100 degrees rounded up and expressed to the nearest minute of arc hex Mag A code number in hex representing the magnitude
109. alogues were pre processed before compiling the Swift catalogue to achieve units Next they were merged into one catalogue before eliminating red objects and precessing all coordinates to epoch 2000 0 All magnitudes are Johnson magnitudes GENERATING MISSING MAGNITUDES All missing V or B magnitudes from the catalogues were generated in preprocessing If V was missing V was set to B 0 3 likewise missing was set to V 0 3 These values were chosen to indicate that the object could be very blue A B V value of less than 0 3 causes the object to be retained in the Swift catalogue after the red objects are eliminated Even if this B V value is invented the UVOT is prevented from looking at potentially bright objects PROCESSING RED STARS The aim of the Swift Catalogue is to prevent the Swift UVOT from looking at very bright objects particularly in the blue range Therefore some fainter objects deemed too red to harm the UVOT have been eliminated from the catalogue This process was done by retaining objects in the catalogue according to these limits V lt 0 3 lt 12 0 0 3 lt lt 0 17 lt 11 0 0 17 lt B V lt 0 01 lt 10 0 0 01 lt B V lt 9 5 Most faint objects with V higher than B could be thrown out according to these rules This reduced number of objects in the Swift catalogue by almost half PRECESSING STARS TO J2000 0 Just over 800
110. an array of 2048 x 2048 virtual pixels with a size of 0 5 x 0 5 arcsec on the sky Faint residuals of a pattern formed by creating the 8 x 8 virtual pixels are removed by ground processing Unlike most UV or optical telescopes because of UVOT s high frame CCD read out rate the UVOT can function in a photon counting mode As with all photon counting detectors there is a maximum count rate threshold The frame rate of the UVOT detectors is 10 8 ms for a full 17 x 17 arcmin frame therefore for count rates above 10 8 counts s assuming a point source a count rate correction needs to be applied A CCD dead time correction also needs to be applied during the data processing Because the local sensitivity of the photocathode can be permanently depressed care must be taken when observing bright objects This is accomplished through autonomous operations diminishing the time spent on these bright sources The detector s dark noise is extremely low approximately 4x10 counts s pixel and can be ignored when compared to other sources of background noise Swift User Manual Swift UVOT 302 R03 High count rates will produce coincidence loss This is an example image showing the effect If the total counts per second on the whole detector are greater than 200 000 counts are lost in the electronics and a dark band appears in the image as seen on this example image Swift User Manual Swift UVOT 302 R03 1 2 2 2 Camera Head The sensor in t
111. and IDPUNOOP DPU No op IDPUPURGEDCX Flush Compression Buffer IDPUPURGESCI Flush Science Buffer IDPUREBOOT Reboot DPU IDPUSTOP Stop DPU Mode IDPUTASK Enables or Disables DPU Monitoring Task IDPUXRTPOS XRT Position IFWABS Move F W to Absolute Position IFWCOARSE Move F W to the Coarse Position IFWDATUM Move F W to Datum IFWFILTER Move F W Position by filter number Swift User Manual Swift UVOT 302 R03 Description Move F W Position by Fine Sensor Pulses Move F W to Relative Position Enable Htrs Specify Heater Algorithm Parameters Enable HV Ramping Enable Disable Direct ICB Commands Read Direct ICB Command Write Direct ICB Commands ICU load command Only support for MIDs 0 1 and 4 ICU load three values command Enables or Disables Limit Checking IMOTORINHIBIT Enable disable auto inhibit of drive INHKECHO The ICU echoes this as an NHK IRTSDISABLE Disable the RTS system Swift User Manual NAME IRTSKILL IRTSRUN IRTSTRACE ISTATE ISTATETRANS ITEST ITIMESYNC IWATCHDOG IWATCHDOGINT SILONGTIMETONE SINOOP SISCATTITUDE SISLEWABORT SISLEWWARNING SITIMETONE XRTCENTROIDERR XRTPOSITION Swift UVOT 302 R03 Description Kills an RTS Runs a relative time sequence Start stops trace on RTSs No State Manager Command Sets allowed automatic state transitions Test or Null Command Set Time Sync Parameters Enable Disable Watchdog Set Reset Interval
112. and token This usually occurs if there has been a corruption of EEPROM P1 the invalid command token in hex P2 the most significant word of the EEPROM address containing the token P3 the least significant word of the EEPROM address containing the token The ICU response is detailed in the Errors Action Table appendix B 8 C 28 DCS Invalid Exec Token 86 hex This error message is issued when an attempt is made to execute an invalid exec function token This usually occurs if there has been a corruption of EEPROM P1 the invalid exec token in hex P2 the most significant word of the EEPROM address containing the token P3 the least significant word of the EEPROM address containing the token The ICU response is detailed in the Errors Action Table appendix B 8 C 29 DCS Invalid Poke Offset 87 hex This error message is issued when an attempt is made to poke to an address outside the valid range for RTS access This usually occurs if there has been a corruption of EEPROM the invalid poke offset relative to the valid address range base in hex P2 the most significant word of the EEPROM address containing the token P3 the least significant word of the EEPROM address containing the token The ICU response is detailed in the Errors Action Table appendix B 8 C 30 DCS Such RTS 71 hex This error message is issued when an attempt is made to run a non existent RTS P1 RTS number of rejected RTS
113. ators Willmann Bell 1985 1 3 10 UVOT State Transitions In order to achieve its goals the ICU must successfully transition the UVOT between several instrument configuration states The possible transitions are shown in the diagram Each state transition is performed by a RTS A look up table located in EEPROM see appendix B 12 contains a list of those RTSs against the requested transition For those transitions that may be autonomous see below it also contains the required state of internal ICU flags for that particular transition to take place This table is used in two ways On command On reception of a telecommand requesting a particular transition that has been issued either from the ground or from a RTS the table is scanned for match against both the current state and the requested state If a match is found the relevant RTS is selected and executed If no match is found the command is rejected Autonomously A number of events will cause the ICU to select the required state transition itself by comparing the table of internal ICU flags against the current values If a match is found the RTS is selected and executed If no match is found the request is ignored The routine events that trigger such a response are settled flag becoming false in SISCATTITUDE record The reception of the FONEXTOBSINFO message e within 10 arc minutes of target flag being set to true in SISCATTITUDE record
114. bed above However it may not be always possible to resume the previous state For instance a slew may now have started or taken place whilst the s c was in the SAA or a settling period may have ended In these cases the ICU looks at the status and selects an appropriate state to which to transition 1 3 12 Overall Data Flow Event and Anomaly Messages Engineering From Values Instrument RTS Request Er Maximum Pointing Exposure Filter 4 Time Information SAA Slew etc Commands RTS request Flags amp XRT Position Commands to Instrument Command Distributor Commands and Messages from S C Swift User Manual Swift UVOT 302 R03 37 The figure illustrates how data flows between the software modules that make up the autonomous system of UVOT and the central position of the RTS system Command Distributor This module receives not only all the commands and messages sent on the spacecraft bus but also all commands internally generated by the RTS Manager It then distributes them to the appropriate software module Observation Manager This module monitors the spacecraft and FOM messages and maintains a record of the status of the ICU It uses this information to determine when it is appropriate to issue a suitable RTS command It accesses the state management tables as well as the AT and PT configuration tables described above as part of this proc
115. bright sources The techniques used to limit or prevent observations when bright sources are known to be present are discussed in the software section of this document This circuit operates independently of the ICU but is under its overall control It has a fast response time of 10s of milliseconds to prevent damage to the detector system The safety circuit is flexible enough to cope with changing circumstances has the facility to be disabled and is insensitive to the effects of penetrating radiation in the CCD and detector During testing of the UVOT image tubes it was observed that in conditions of high event rates when the overall system would in normal operation be showing significant coincidence losses there was a broadening of the event profile This was found to be predominantly an effect of the image tube It was considered that this repeatable characteristic provided a good indication of source brightness Consequently the safety circuit design is based on measuring the maximum width of a star profile The system connects between the camera and the BPE and scans the raw video data for a predetermined number of consecutive pixels above a preset amplitude threshold see diagram To ensure immunity to the effects of penetrating radiation these consecutive pixels must be present for multiple consecutive frames It is also necessary to ensure that only valid pixels from the Image nM Intensifier camera were analyzed This
116. can be changed with the command iiculoadl mid 0 offset 0x900 150 0 data 0x400 0x200 0x100 25 For release 10 of the UVOT ICU code the contents of the table are shown below Swift User Manual Swift UVOT 302 R03 Record S NHK Error Code NHK Parameter Match RTS to run Offset 0 Table length in words 1 HEATER ICB SHUTDOWN match all noaction 4 CORRUPTED EEPROM CMD DTB ID h emergency safe 7 CORRUPTED EEPROM RTS NDX ID h emergency safe 10 CORRUPTED EEPROM RTS NDX HDR ID h emergency safe 13 CORRUPTED EEPROM RTS STORE ID h emergency safe 16 CORRUPTED EEPROM HV CALIB ID noaction 19 CORRUPTED EEPROM HV CALIB 2 ID gotosafe 22 CORRUPTED_EEPROM LIMIT CHECK TABLE ID h basic 25 CORRUPTED EEPROM HEATER TABLE ID h basic 28 CORRUPTED EEPROM STARCAT ID gotosafe 31 CORRUPTED EEPROM AVOIDANCE ANGLES ID gotosafe 34 CORRUPTED_EEPROM AT CONFIG TABLE ID gotosafe 37 CORRUPTED_EEPROM PT_CONFIG_TABLE_ID gotosafe 40 gt CORRUPTED EEPROM PT CONFIG ID ID gotosafe 43 CORRUPTED EEPROM STANDARD TABLE ID gotosafe 46 CORRUPTED EEPROM STATE TABLE ID gotosafe 49 CORRUPTED EEPROM ERRORS ACTION TABLE ID gotosafe 52 CORRUPTED EEPROM COUNT RATE TABLE ID gotosafe
117. ct this behaviour as even when the spacecraft is not in the SAA the SAA state may be briefly shown 1 3 11 4 Slew Warning Upon receiving a slew warning from the spacecraft in the form of an SISLEWW ARNING record the ICU ensures the Vcathode is set to zero It then informs the spacecraft that we are safe to slew by sending an SACSLEWSAFEREPLY At that point it has transitioned to the Slew state If the UVOT then receives a FONEXTOBSINFO record it performs an AT or PT observation in their respective states If the contents of the 5 Hz attitude control system ACS record imply we are going to a safe pointing it proceeds to the Safe Pointing state If neither of the above happens it assumes an error condition and proceeds to the Idle state However for PT and AT exposures the ICU has to verify for the target position that there are no bright planets and by examining the on board catalogue that there are no detector damaging bright stars present If there are bright sources at or close to that position it must ensure that the exposure does not take place and take appropriate corrective action for example by reducing the gain of the image intensifier and placing the UVOT into idle state The actions for Safe Pointing observations are described below in section 1 3 11 7 1 3 11 5 AT Observation NOTE For all types of exposures the ICU maintains a running theoretical total of counts received so far at each catalogued star position in the
118. ctions performed on the bus is controlled by software in the ICU The functions performed via the ICB are e Loading of tables into the detectors Commanding of the detectors Status monitoring of detectors Reading filter wheel position sensors and temperature sensors Controlling power switching Controlling heater switching Controlling motor drives Monitoring voltages currents Swift User Manual Swift UVOT 302 R03 6 The MACS bus specification defines a redundant bus Redundancy is provided in Swift by two separate detector chains and therefore only one MACS interface is used per redundant half The ICU always drives the clock on its bus Possible commands are e l bit transfer of data from the ICU to the sub system initiated by the ICU ICBsend e l bit transfer of data from the sub system to the ICU initiated by the ICU ICBacquire These ICB commands are made up pairs of ICB words ICB words are 24 bits long and can be of one of two types ICBinstruction or ICBdata ICBsend ICBinstruction ICBdata 3 5 13 1 21 22 23 3 5 21 22 23 101 ICUaddr dest subaddr 010 011 00 data 3 5 5 5 3 1 1 1 3 2 16 1 1 1 The ICU generates both ICB words ICUaddr The ICB address of the ICU Dest and subaddr Define the sub system which should respond to this command Par Parity for the word Err Error condition if true the c
119. current observation This may be because either that UVOT mode is non existent or because it has no entries for that value of the time since burst The AT table is described in appendix B 6 1 Requested UVOT Mode P2 Most Significant Word of the time since burst in seconds and hex P3 Least Significant Word of the time since burst in seconds and hex The ICU response is detailed in the Errors Action Table see appendix B 8 C 87 No Such UVOT PT Mode 48 hex This error message is issued when the ICU could not find a match in the Planned Target PT table for the current observation The PT table is described in appendix B 9 1 Requested UVOT Mode The ICU response is detailed in the Errors Action Table see appendix B 8 C 88 No Usable Filters in Config 4a hex This error message is issued when the ICU could not find a suitable filter when attempting to perform an AT exposure This happens if in human error the exposure table described in appendix B 6 has accidentally specified that no filters should be used for the UVOT mode or for safety reasons it is no longer possible to exposure in any filter 1 Requested UVOT Mode P2 0 P3 0 The ICU response is detailed in the Errors Action Table see appendix B 8 C 89 Notat Predicted Position 4e hex This error message is issued when the ICU detects that we are not pointing at a predicted position within tolerances specified in the on board standard EEPROM
120. currents voltages etc Swift User Manual Swift UVOT 302 R03 1 Appendix Detailed Description of EEPROM A Located Tables A 1 Overview The Basic code resident in ROM only has facilities to access data in the EEPROM A bank Therefore the tables listed below are located in EEPROM A to supply information needed by that code In addition because of the safety critical nature of that data two copies are kept to guard against failure The code will automatically switch to the second copy if it detects a CRC failure Name Start End Comments HEATER CONTROL 1FA00 1FA2F Heater Control Parameters HV RAMP 1FA30 IFA6F High Voltage Ramp Parameters LIMIT CHECK 1FA70 FCFF On Board Limit Checking HEATER CONTROL 2 1 00 1FD2F Copy of HEATER CONTROL HV RAMP 2 1FD30 FD6F Copy of HV RAMP LIMIT CHECK 2 1FD70 1FFFF Copy of LIMIT CHECK A 2 Heater Control A 2 1 Overview The behaviour of the heater control algorithms on UVOT is determined using parameters stored in this on board EEPROM table There are two types of heaters focussing and non focussing with different algorithms A 2 2 Non Focussing The parameters control a bang bang algorithm i e the INTERFACE and FORWARD heaters should be off when the temperature is above a specified range and on when below a specified range TMin Vnom Specifies the lower value of the allowed temperature in raw thermistor i e uncalibrated units
121. e Suruuni SITS LY ON zi 0X Ts DEOS PME 229 3 Dv Ws i8 P E 24 Fw NC ix M Sn 00115062 4 24 3 OY peusrur JAVY SB KEET lt 52098 91815 81918 xas OS IA pue TE Xx x 2 Cel 9 E 0197 Je SI 522 ye dourA pue ccdourA TEXUCORXIDTO ECFA Y CX nm va baal it te al ril Se E peril lt 41 amp 2 4 5 275 ve 7 3t Mt sale 54 erg wy A sha 7 3 au 12 vez 3 152 12 IS a dmg wi Iss 4 12 153 c ad ug 222 NAE 4H SeS Ad ecg ant 74 E 4 F4 b iene EI gt GEI YNA X MF 1 i er 4 rey gt X Sb bear 24 FAA X 19 3 0 39 AI el 5 2
122. e 10 of the ICU code The precise action is determined one of three ways 1 From details given in the errors action table in EEPROM B described in appendix B 8 2 In the case of a Limit Violation from the Limit Check table stored in EEPROM A described in appendix A 4 3 From the time out action detailed in the currently running RTS if an expected action fail to occur C 2 5 ACS Packets Missing 8f hex No SISCATTITUDE packets were counted in 1s This is caused by loss of Spacecraft SISCATTITUDE packets or the UVOT ICU telecommand software is not working or being slowed by other tasks There are no parameters associated with this message The ICU response is detailed in the Errors Action Table see appendix B 8 C 3 Ada Exception ec hex An Ada exception has occurred P1 FIRST EXCEPTION the first exception of a sequence of exceptions P2 LAST EXCEPTION the last exception of a sequence of exceptions P3 FIRST PROGRESS the last progress line passed at the time of the first exception The format of the parameters in hex is of the form PPNN PP is a code see the Message Codes appendix D 16 indicating which Ada package issued the exception or in which the progress line is located NN is used in two ways For exceptions it indicates both which procedure in that package issued the exception and what type The precise values used can only be obtained by examining the code and will change with each version For progress lines NN S
123. e AIV 7 6 V AIV 5 1 UVW2 AIV 32 White G2V 7 0 V G2V 5 1 V M2V 5 0 White M2V 7 0 If the total predicted counts received for any star during a pointing 0 45 min reaches 1 000 000 000 the exposure is terminated and the next filter tested 1 3 8 The RTS System 1 3 6 1 Overview The RTS scripts provide a separate layer of software on top of the Ada code They deal only with the higher level aspects of UVOT control As the Integrated Test and Operations System ITOS is used as the satellite control and monitoring system for the Swift mission the syntax of the RTSs is by design similar to ITOS procedures which in turn are somewhat like Unix scripts RTSs therefore act as an on board UVOT command facility into which changes in ideas and circumstances can more readily be incorporated Only one top level RTS may run at any time although it may call other RTSs as subroutines Each RTS is assigned a priority which is also used by any RTSs called If a commanded RTS has a higher or same priority than the one Swift User Manual Swift UVOT 302 R03 27 currently running the latter will be shut down and the new RTS run in its place Any RTS with a priority greater than 32767 is treated as a pseudo interrupt routine When it completes any RTS or call stack of RTSs interrupted is restarted at the top level Priorities are set based firstly on safety and then on science considerations 1 3 8 2 Summary of RTS Scripts The list is for relea
124. e flow control statement also supports Boolean for example and or and relational for example greater than less than operators Internal calls These are commands to procedures supplied by the underlying Ada code They therefore act as calls to built in functions An example of this is a call to the procedure that loads the selected exposure configuration into RAM from EEPROM Return In the case of a top level RTS this causes it to stop executing For a lower level RTS it results in a return of control to the calling RTS Exit The current RTS and any RTSs calling it stops executing Messages A facility similar in concept to the Unix echo command is provided This allows appropriate diagnostic or error messages to be sent to the ground Symbolic Constants and Comments These are provided to make the scripts more human readable 1 3 9 The Bright Source System To determine if there are known bright sources close to or in the field of view a planetary position calculations are performed and b the on board star catalogue is checked Unknown or unexpected bright sources are handled by the safety circuit system see section 1 2 2 5 Swift User Manual Swift UVOT 302 R03 31 1 3 9 1 On Board Catalogue The ICU software uses an on board star catalogue to determine the magnitude and colour of stars in or close to the target field of view This information is used in two ways to protect the detecto
125. e majority of onboard functions e g all CCSDS secondary header time tags and management of stored command processing functions The spacecraft clock is set at initial power on and is nominally run at 1 Hz rate without adjustments The UTCF is a bias that is adjusted such that the sum of the spacecraft clock with the UTCF yields a time that is as close as possible to UTC The spacecraft transmits time to all instruments Spacecraft time and a Universal Time Correlation Factor are transmitted over the 1553 bus once every second and are valid at the next one pulse per second 1 2 Telescope Module 1 2 1 TMPSU The telescope module power supply TMPSU converts the spacecraft power bus to power rails within the telescope module One set of rails powers the blue digital and analogue electronics and high voltages The analogue electronics in turn controls the high voltages and powers filter wheel fine sensor LED and flood LEDs The other set power the mechanisms and filter wheel coarse sensor The integral ICB interface provides the channel for control of the coarse sensor the flood LED s the analogue and digital electronics and the return of current high voltage and fine sensor status values Additionally the main s c power routed via the TMPSU is used to drive the heaters 1 2 2 Detector System 1 2 2 1 Overview There are two detector assemblies Each detector assembly consists of detector window that is slightly figured a 520 photocathode
126. e object A difference in brightness between the nucleus and extended regions of the source was allowed for galaxies with bright nuclei this difference was found empirically Extended sources from the NGC catalogue with core V lt 11 0 were used Core Bt magnitudes were inserted with value V 0 3 YALE BRIGHT STAR CATALOGUE The Yale Bright Star Catalogue ref Yale Bright Star Catalogue 5th Revised Ed Hoffleit Warren 1991 lists coordinates magnitudes and spectral information for over 9 000 of the sky s brightest stars This catalogue was added since some of the very brightest stars 1 Sirius seemed to be missing from Tycho 2 The catalogue contains stars and 14 other sources with lt 6 5 Empty B V fields were set to 0 3 B fields were determined by V B V B 2 2 Star Catalogue Structure The onboard catalogue is split into three parts the pointer table the main catalogue and the addendum It is stored in EEPROM B The three parts of the catalogue follow each other sequentially with no gaps The pointer table allows quick access to catalogue data and the addendum is an area left blank in case any sources need to be added to the catalogue after launch for example if a supernova occurs during the mission B 2 3 Star Catalogue Pointers The star catalogue is divided into sky areas of approximately equal solid angle This pointer table holds a set of pointers to allow rapid access to a particular sky area and
127. e of crashes C 11 Bright Object Present 46 hex This major anomaly message is issued if on updating the sun moon and planets positions usually once per slew via an exec call to bright planets from an RTS it is detected than one or more of those sources is now violating its angular constraint Note that it is an event message so that any error handling is performed by the calling RTS rather than by the table controlled NHK error handling mechanisms P1 1 gt 10 hex a defines which bright object see Planet Code Table D 7 in the Message Codes appendix P2 Angular distance from current pointing position of source in minutes of arc and hex P3 z Current UVOT Mode The ICU response is detailed in the Errors Action Table see appendix B 8 C 12 Bright Star Report SID da hex This message is issued to indicate that relative to the predicted target position and according to the on board catalogue the described bright star is within its tabulated angle of avoidance This normally precludes a safe Swift User Manual Swift UVOT 302 R03 4 observation as the maximum safe exposure length is then set to zero The format of this message is non standard The fields are the same as in the Catalogue Star message described in appendix C 15 C 13 Bright Star Store Exhausted 4f hex This event message is issued when the on board working copy of catalogued stars in the current target field of view has exceeded its memory allocation This norm
128. e original specification it was incorrectly documented that the ICU would be off F 21 MSSL 132 The ICU code unnecessarily checks for within 10 arcmin when in SAFE state F 22 MSSL 134 SERS S 0067 The ICU timed out waiting for a slew to start on 2005 02 21 This was because the ICU was busy checking the star catalogue after settling on a safepoint when another slew was requested Was this a little abnormal because of the crazy BAT recovery see Anomaly Report S 0065 but is nevertheless a bug in the ICU Ada code Ada function Swift User Manual Swift UVOT 302 R03 6 GET_PT_CONFIG can take long time and needs first of all to be timed to see how long it takes and then needs to be changed to make it interruptable by a high priority RTS F 23 MSSL ECR 153 The filter wheel FW rotation life consumed by the 80 96 PT snapshots expected per day is a significant concern The current ICU design provides no mechanism to keep the UVOT idle during un interesting PT snapshots preventing FW motion It seems possible that the SOT may from time to time wish to point Swift at a target that s known to be unsafe for the UVOT or at an uninteresting target that would produce more wear on the detector than scientific benefit The current ICU design provides no mechanism to explicitly keep the detector Cathode down in such circumstances Both the FW life concern and the safety concern could be addressed by implementing a UVOT_MODE value that
129. e range 1 00 to 1 00 These values are multiplied by 1000 for up link purposes Swift User Manual Swift UVOT 302 R03 15 The tables are loaded from the ICU via the ICB 1 2 2 6 4 Output Data Formats The output of the processing electronics to the DPU is a series of 24 bit words one per event processed A maximum of 200 00 events is supported The format of the word is determined by the data acquisition mode set via the ICB and is detailed in the figure overleaf There are four scientific modes numbered 0 to 3 and effectively two engineering modes numbered 4 to 7 The normal mode for science observation is 3 High Resolution Full The scientific modes provide event positions in the form of the x and y CCD pixel number the sub pixel number in x and y and for the windowed modes only 0 and 2 the window ID of the window in which they occurred There are two full frame modes where the window ID is replaced by the most significant bits of the x and y CCD pixel counters thus giving 16 tiles covering the full detector area NOTE the windowed modes are present only because they were required for the heritage instrument XMM OM The ICU is still capable of commanding the instrument to supply this form of data However the DPU was not required to support them Consequently the UVOT only supports the full frame modes The engineering modes provide information for setting up and checking the detector Modes 4 or 5 capture centroiding information
130. e upload is to replace the ICU code as opposed to and RTS location the next step is replace the code currently running in RAM with the new version now in EEPROM This is done using the i cu_reload proc This works by once it has checked that the ICU is in Safe requesting it to go again to safe This is understood by the on board code to force a reload of RAM from EEPROM Whilst this process is taking place the ICU is not functioning Therefore the procedure also informs the s c not to expect a response to a slew warning The final stage in the process is to return the ICU to full operational state using the icu_idle proc See section 2 3 5 1 for a description 2 3 14 UVOT 14 DPU Upload BC1 Code Image TBA 2 3 15 UVOT 15 DPU DCI Lockup Recovery TBA 2 3 16 UVOT 16 Recovery from Watchdog Trip This procedure describes the steps necessary to recover the UVOT after a Watchdog Trip Unexpected events are handled on the UVOT by a Watchdog Reset see Watchdog section 1 1 1 5 After the reset the IUVOTSTATE will be BASIC Before returning the UVOT to normal operations contact the UVOT subsystem engineer to verify the cause of the Watchdog Trip The transition to SAFE state using the icu_safe proc described in section 2 3 4 1 can be done immediately However do not execute icu idle described in section 2 3 5 1 without the go ahead from the UVOT subsystem engineer 2 3 17 UVOT 17 DPU Upload Table TBA 2 3 18 UVOT 18 DPU Uplo
131. ecovery technique 2 3 12 1 Recovery 1 The filter wheel loses its position and recovers immediately the partial messages reported will be as follows FW Lost Position AT REQUESTED FILTER POSITION 2 3 12 2 Recovery 2 The filter wheel loses its position and recovers after another attempt to move the filter wheel the partial messages reported will be as follows FW Lost Position FW Not Yet Datumed AT REQUESTED FILTER POSITION Note If the filter wheel cannot be recovered after two attempts the ICU will be transitioned to SAFE mode using the RTS gotosafe 0x11 The UVOT subsystem engineer should be contacted immediately 2 3 13 UVOT 13 ICU Code RTS Upload This procedure describes the steps necessary to load new ICU code and or new RTS definitions If during normal operations it is determined that the ICU code or the default RTS definitions need to be modified this procedure should be used as a template to accomplish this First the icu safe proc is run to ensure the ICU is in safe mode see section 2 3 6 for details of this proc If the reload that is about to take place is to an area of EEPROM containing RTSs or the index to the RTSs then the RTS system should be disabled with rt sdisable disable 1 command The proc iload chunk is then used to load to EEPROM see the procedure for details Swift User Manual Swift UVOT 302 R03 45 A spacecraft RTS is then run to dump the memory loaded for verification If the cod
132. ector Window Origin Y Units 2 2 CCD Pixels range 0 gt Ox7f 17 Detector Window Size X Units 2 2 CCD Pixels range 1 gt 0x80 18 Detector Window Size Y Units 2 2 CCD Pixels range 1 gt 0x80 19 DPU Finding Chart Control Word 20 21 DPU Minimum Tracking Window Area 22 23 DPU Tracking Frame Time seconds 24 DPU Number of Guide Stars range 0 gt 0x10 25 DPU Criteria Mask 26 Flood LED Setting range 0 gt 15 27 Detector Threshold 28 Exposure Modifier 0 PT Normal 1 PT Null 2 PT Idle see table below Swift User Manual Swift UVOT 302 R03 Mond Description Offset 29 If not equal to zero actual filter wheel position required usually for clocked grisms 30 Unused 31 Safety Circuit PCTHOLD Consecutive Pixel Count parameter range 0 gt 7f 32 Safety Circuit FCTHOLD Consecutive Frame Count parameter range 0 gt 1f 33 Safety Circuit STHOLD Pixel Threshold parameter range 0 gt ff 34 Safety Circuit RTHOLD Rate meter Pixel Threshold parameter range 0 gt ff 35 CRC Exposure Modifier Table Exposure Modifier Description PT Normal Exposure carried out as normal PT Null The filter wheel is left at its current position and the cathode is set down PT Idle The filter wheel is moved to blocked and the cathode set down Swift User Manual Swift UVOT 302 R03 B 13
133. ed 1 jsperedg LOAN eu I ssed 104 7 jsiperoodg LOAN 99 I post MoMA post d oruoueuw 0 CO LOA 13JIAS Tenue A 1951 IIMS nor 3 35 pue 52024 6 3aInpaoord SNIS pue ayes 11818 2014 1016 pue SUYES 9 LOAN usellUA orseq ol 08 Sruur Jo lno 198 ps uo TAUT 120 1347 o qesiq E 25 jsmeroedg LOAN SUPY 71 spoy e1npoooud uonrsod 1501 TeeqA 29310 o3nooxq 104 JelUnoD 511295 nd LOAN I uonisod i aite LL AN B SMIS ages nor 3 35 2014 1015 Sunnooxo BOnEIOTA pue 94 LOAN empoooid UPM 9819 AAVS T ALVLSLOANI AUT 9884 ol 8 sey LOAN psdD 99 LOAN WOJU LOA S3e T 51395 NSd dui uoT oes eis 2 jsiperoodg 5804 LOAN smeig v 84
134. ed with this message C 17 Centroid Table Load Aborted 6e hex This event message is issued as confirmation when a load centroid table command is stopped by command C 18 Centroid Table Load Failure 64 hex This error message is issued when a centroid table load fails This happens when there has been 1 MACSbus errors when writing or reading the table or 2 verification errors caused by a mismatch between what was found in the table and what was expected Yes No The ICU response is detailed in the Errors Action Table see appendix B 8 C 19 Centroid Table Load OK 63 hex This event message is issued as confirmation when a load centroid table command has completed successfully C 20 Corrupted EEPROM Data 92 hex This error message is issued when an area of EEPROM has failed its CRC check the CRC for any of the designated areas should always be zero The ICU response is detailed by the Errors Action Table see appendix B 8 Description P1 ID Hex P2 hex HV_CALIB_ID CRC Found Star Catalogue Section ID CRC found AT Block CRC fund LIMIT_CHECK_TABLE_ID HEATER TABLE ID STARCAT ID AVOIDANCE ANGLES TABLE ID AT CONFIG ID STANDARD TABLE ID STATE TABLE ID 0 _ _ CMD_DTB_ID RTS_STORE_ID ERRORS ACTION TABLE ID COUNT RATE TABLE ID PT CONFIG ID Swift User Manual Swift UVOT 302 R03 C 7 PT Mode CRC found
135. em The primary functions of the DPU Flight Software are e Receive and execute commands received from the ICU and the spacecraft e Receive and process detector events from the UVOT Telescope Module e Perform lossless data compression of image and or photon event data On board source detection for generation of UV Optical finder chart Generate science data telemetry products e Generate engineering data telemetry products e Forward packetized compressed data to the spacecraft Solid State Recorder e Maintain time synchronization with the spacecraft The DPU communicates with the ICU through the Synchronous Serial Interface and receives raw photon position and timing data from detector electronics across a serial Data Capture Interface Because the amount of photon event data that can be collected exceeds the UVOT telemetry allocation the DPU employs histogramming and modified VBTWL data compression to reduce the size of its telemetry data products The DPU formats data as Consultative Committee for Space Data Systems CCSDS Source Packets and forwards telemetry to the Spacecraft Control Unit SCU through a MIL STD 1553 1553 interface Housekeeping and science telemetry timestamps are synchronized with the spacecraft clock Swift User Manual Swift UVOT 302 R03 39 2 Instrument Operation 2 1 Safety Issues The UVOT detector telescope is damaged by bright light particularly when the three high voltages are up Vmcp23 Vmcpl 4
136. er appendix E 1 for a brief description of each command APID hex F C Command hex appestanreNTRDED Lemon mppesTaRTWNDWLD Lemon o os meeacowons Lees pw o 660 670 21 AICBWRITE Swift User Manual APID hex 660 670 660 670 22 660 67 30 660 67 31 660 67 40 660 or 67 41 660 67 42 660 67 43 660 67 44 660 67 45 660 67 46 660 67 47 660 67 48 660 67 49 660 67 50 660 67 51 660 67 51 660 67 62 660 67 62 660 67 62 660 67 63 660 67 70 660 67 660 67 81 660 67 81 660 67 82 660 67 92 660 67 92 660 67 92 660 67 93 660 670 94 1 5 ommand IBPESTOPCNTRDLD IWATCHDOGINT IFWSTOP IFWSETRATE IFWFILTER IFWABS IFWPULSE IFWDATUM IFWCOARSE IMOTORINHIBIT IHTR IHTRPARAMS IBPESFTYCONFIG IRTSRUN IRTDISABLE IRTSTRACE IHK I
137. er of arguments are supplied in a call to an RTS P1 Number of supplied arguments P2 Argument number at which the problem was detected C 36 Debug Output f0 hex The value of the parameters is determined by the values the programmer has chosen to supply C 37 DM at Requested Position 68 hex This event message is issued as confirmation that a dichroic move was successful P1 20 if it was being moved to its maximum excursion otherwise it was being moved a requested number of steps P2 if it was being moved in a positive direction prime to redundant 3 if it was being moved in a negative direction redundant to prime C 38 DM Lost Position 6a hex This error message is issued when a dichroic move was aborted on command P1 20 if it was being moved to its maximum excursion otherwise it was being moved a requested number of steps P2 1 if it was being moved in a positive direction prime to redundant 3 if it was being moved in a negative direction redundant to prime The ICU response is detailed in the Errors Action Table appendix B 8 39 Ack Nack No error event code displayed This DPU event message is forwarded via the ICU when the DPU receives a command from the ICU ACK is displayed if the checksum was correct NAK if was not The function code of the received command is also shown For full details see ICD for the ICU DPU Protocol for the UVOT C 40 DPU Bad Bounds 36 hex This error message
138. era Optical Bench Observatory Duty Scientist Random Access Memory Programmable Readonly Memory Point Spread Function The Pennsylvania State University Pre Planned Target Quality Assurance Regular Frequency Relative Time Sequence South Atlantic Anomaly Spacecraft Swift Data Center Spacecraft Emergency Response System Science Operations Team Software To Be Added Tracking and Data Relay Satellite Systems Telescope Module UVOT Instrument Duty Specialist UVOT Institutional Manager Ultra Violet and Optical Telescope Swift User Manual Swift UVOT 302 R03 Table Of Contents 1 Instrument Description 1 1 Digital Electronics Module DEM 1 1 1 1 1 2 1 1 3 ICU DPU Interfaces 1 2 Telescope Module 1 2 1 1 2 2 1 1 2 3 1 2 4 1 2 5 TMPSU Detector System Mechanisms Flood LED s Heaters and Thermistors 1 3 ICU SOFTWARE 1 3 1 1 3 2 1 3 3 1 3 4 1 3 5 1 3 6 1 3 7 1 3 8 1 3 9 1 3 10 1 3 11 1 3 12 Overview Scientific Requirements Engineering Requirements Constraints on Observing Available Information Design Philosophy EEPROM Located Tables The RTS System The Bright Source System UVOT State Transitions Observing Sequences Overall Data Flow 1 4 Software 2 Instrument Operation 2 1 Safety Issues 2 2 Noise on HV measurements 2 3 UVOT Procedures 2 3 1 2 3 2 2 3 3 2 3 4 2 3 5 2 3 6 2 3 7 2 3 8 2 3 9 2 3 10 2 3 11 2 3 12 2 3 13 2 3 14 2 3 15 UVOT 01 Earl
139. erature sensing circuit outputs are ORed together to reset this latch Once a circuit has tripped the temperature must go back down before this latch can be successfully written to The DISMON circuits are enabled on power up of the TMPSU The circuits can be enabled and disabled by writing to the MSB of address 3 in the memory map of the TMPSU Writing to this bit controls both temperature control circuits Writing a to this bit enables the circuits to control the motor latch address 2 and writing a zero to this bit disables the temperature circuit from controlling the motor latch In the second case no temperature effect can control the motor latch and the motors can be run indefinitely The status of the DISMON enable circuit is reported in the housekeeping Bit 14 reflects whether the circuit is enabled or disabled A indicates it is enabled default condition on power on and a zero indicated the circuit is disabled The status of the DISMON temperature circuits is reported as an analogue parameter in HK channel 7 During the Thermal Vacuum testing of the FM2 TMPSU it was found that under hot temperature conditions the DISMON circuit tripped even though no winding was on At room temperature the ballast resistor of the dichroic motor did not fire The FM1 exhibits the same behaviour Note also the FM2 Filter Wheel circuit thermistor is not fitted so will never fire Swift User Manual Swift UVOT 302 R03 21 1 2 4 Flood
140. eries of data blocks each linked to the next by a memory pointer although for release 10 of the UVOT ICU code they are actually contiguous in memory As the list is searched linearly the less frequently used UVOT Modes as stored in the later blocks Each block is terminated with a CRC for the whole block Within each block there are a series of contiguous three word records of the following form Word Offset Description 0 Mode 0 gt Ox7ffE Note 1 gt 8 are used for safe pointing settling and finding exposures 1 Location of an exposure configuration in the PT Configurations table see above 2 The ICU determines the exposure configurations required for a given snapshot by scanning this set of linked blocks On finding a record within a block that contains an UVOT Mode matching that in the associated FONEXTOBSINFO the code scans only the rest of that block for any further records that match the Mode The resulting list of exposures is used for the current snapshot If the UVOT mode is greater than or equal to 0x1000 all the separate requested exposure times in the indicated exposures are summed This number is compared to the time available for observing that is also supplied in the FONEXTOBSINFO record and the exposure times scaled accordingly to fit For other values of UVOT mode the exposure times are unaltered The exposures are then executed in the order given in this table Each
141. ess Bright Objects Manager This returns information about planets and stars near or in the target field of view using the star catalogue and avoidance angle tables described above Limit Checking This monitors critical engineering values Using the table described above it issues requests if necessary for a RTS to perform recovery actions from a limit failure Telemetry Queue Manager This monitors all outgoing telemetry for error messages and using the table described above issues a request to run a recovery RTS if required RTS Manager This module executes the RTS It consists of the virtual CPU code to execute the RTS together with software to scan the RTS index image to permit rapid location of a given RTS Swift User Manual Swift UVOT 302 R03 38 1 4 DPU Software The DPU software is built upon a VxWorks Real Time Operating System Bootstrap and device driver software for the SSI DCI 1553 interfaces were developed by Southwest Research Institute SwRI Application level science Data Processing Algorithms software was developed by Penn State University This layered approach to software development was critical to completing the software on time and under budget as it provided a clear division of labor between the two institutions Data Processing Algorithms Science Data and Application Interfaces APIs Processing Software Operating System Memory Management amp Device Drivers DPU Hardware RAD6000 Com M
142. field of view Should this number approach an EEPROM tabulated damage limit it will shorten or even suppress the exposure accordingly See also SAA Interruptions section 1 3 11 8 below AT observations are handled in two distinct ways depending on whether the source has been observed during a previous snapshot If the I5 SLEW parameter in the FONEXTOBSINFO record is true then this is the first time it has been observed 1 3 11 5 115 NEW SLEW True The ICU will transition from the Slew state to the Settling state when the IS 10 ARCMIN flag in the ACS becomes true It will then perform a settling exposure until the spacecraft becomes settled IS SETTLED is True It Swift User Manual Swift UVOT 302 R03 35 then transitions to the Finding Chart state and performs a 100 second finding chart exposure Upon completion it automatically transitions to the AT state and performs the first of a sequence of exposures Its behaviour from this point is the same as if IS_NEW_AT_SLEW False see below 1 3 11 5 215 NEW SLEW False The UVOT transitions to the AT state and perform the first of a sequence of exposures The precise sequence used is selected from a list stored in EEPROM using 1 The UVOT Mode parameter which will be in the range 0x8000 to Oxfffe supplied by the Figure of Merit FOM in the FONEXTOBSINFO record 2 Arefined target position which may be sent by the XRT during the finding chart exposure
143. following written procedure documents This includes more detail of the possible errors that may be seen because of the many separate actions implied by each telecommand of the procedure 2 3 1 UVOT 01 Early Orbit Turn on This is described in UVOT Launch and Early Orbit Timeline and Turn on Procedure SWIFT UVOT 040 2 3 2 UVOT 02 Emergency Power Off Under normal circumstances a S C problem i e Safehold Mode will place the UVOT into the Safe state In the event this did not occur or a problem is discovered with the UVOT the UVOT subsystem engineer may direct the FOT to execute this procedure The emergency power off procedure executes RTS 3 followed by procedures to fully power down the telescope modules and DEM RTS 3 sets rather than ramps down the high voltages to zero turns off the camera ensures the flood LEDs are set to zero and then initiates a filter move to blocked However no check is performed that the latter action actually occurs before setting the state to safe as the emphasis is on speed It is therefore possible depending on the nature of the emergency and position of the filter wheel to power off the UVOT before the filter wheel has finished moving thus leaving it in an open position As several of the above actions go against the advice given in the above section on safety issues it is clearly advisable to only use this procedure in extreme circumstances The routine power off procedure will normally be used t
144. for conversion to filter value see FILTER TABLE appendix D 4 C 61 FW Lost Position 69 hex This error message is issued when a filter wheel move was unsuccessful because 1 the fine sensor was not detected after a normal filter wheel move or 2 either the fine or coarse sensor was not detected after a move to datum Type of Filter Wheel movement requested see Types of FFW Movement table appendix D 3 in the Message Codes appendix P2 z Number of steps just moved P3 2200 The ICU response is detailed in the Errors Action Table appendix B 8 C 62 FW Move Aborted 6d hex This event message is issued as confirmation that a Filter Wheel move was aborted by command Type of Filter Wheel movement requested see Types of FFW Movement table appendix D 3 in the Message Codes appendix P2 z Number of steps just moved P3 Current Filter Position for conversion to filter value see FILTER TABLE appendix D 4 C 63 FW Not at Blocked 6c hex This is issued both as a Verification Error and as a Major Anomaly message depending on the circumstances A Verification Error is issued when and attempt is made to set the flood led to a non zero value when the filter is not at blocked The APID and Function Code returned should be used in conjunction with the Command Table in the Message Codes appendix D 2 to determine which command was rejected An Major Anomaly message is issued when and attempt is made to ramp
145. ft UVOT 302 R03 B 5 RTS Database The RTS index see above gives the start address RTS_START of a particular RTS That address is always a multiple of 32 16 bit words The layout of each RTS is as follows B 8 Word Offset Description of Contents RTS_START Length in words of RTS RTS_LENGTH including itself As RTSs are often contiguous this may also be the offset to the next RTS Then followed by up to RTS_LENGTH 2 RTS command tokens Any unused words prior to the CRC are zero filled RTS_START RTS_LENGTH 1 CRC for RTS Swift User Manual Swift UVOT 302 R03 B 9 B 6 AT Configurations B 6 1 Overview The AT configuration table contains a set of data blocks containing experiment configurations to be used during Automated Target exposures Note that they do not include the finding chart or settling configurations which are treated by the UVOT ICU as special cases of planned target exposures PT see appendix B 7 The data blocks are arranged as a series of linked lists the order within the list being time since burst The precise configuration used is determined by The UVOT Mode parameter supplied by the Figure of Merit FOM in the FONEXTOBSINFO record The intensity of the GRB as transmitted in the IGRBFLUXINFO packet The time since the burst supplied in the FONEXTOBSINFO Whether a refined XRT position in an XRTPOSITION message has been received The filter used in the last
146. ft UVOT 302 R03 D 20 Error Event Description Code hex DM at Requested Position e Centroid Table Load Aborted Window Table Load Aborted DCS Call Depth Exceeded DCS Insufficient Priority e 5 ACS Packets Missing ICU Watchdog Trip EE ME NN EE NE E zoe NEN BEI Swift User Manual Swift UVOT 302 R03 Code hex D 21 Swift User Manual Swift UVOT 302 R03 0 15 ICU ERROR EVENT CODES IN ALPHABETICAL ORDER Note turn to the previous table for the error codes in numerical order Code hex 1 x I 54 Angular Constraint Violation 5 Automatic State Trans n Req d Bad Data in EEPROM Bad Value BATGRBFLUXINFO Proc Stat _ __________ se s _ 5 _ m Const EPROM o _ w e p3 pcs mara Commana Toen Swift User Manual Swift UVOT 302 R03 Code hex FW at Requested Position FW Lost Position Oo gt 3 a HV Above Below Requested HV Calibration Data Failure NTA D 23 Swift User Manual Swift UVOT 302 R03 D 24 Code hex oo e o State Transition Complete Switching RTS ee E E NE NN Swift User Manual Swift UVOT 302 R03 Code hex D 25 Swift User Manual Swif
147. ft User Manual Alert reset This function resets the cathode safe signal register to its power up default state off allowing control of the cathode voltage and returns the alert flag to zero The safety circuit is also reset to its power up default state It should be noted that safety circuit settings are not affected by this signal and that the previous state will be maintained until it is reconfigured or reset by power cycling Note after asserting this signal must be de asserted otherwise the circuit will be continuously reset and therefore not function Alert enable This function enables the cathode voltage control register The alert flag is not affected by this control This allows for on orbit calibration of the system without turning the cathode voltage off whenever the alert flag is set Input threshold preset This read write register allows the pixel threshold STHOLD to be set Only the most significant five bits are used Consecutive pixel preset This read write register sets the number of consecutive pixels PCTHOLD that must be greater than the input threshold to trigger the frame counter Consecutive frame preset This read write register sets the number of consecutive frames FCTHOLD that are required to be above both the input and consecutive pixel thresholds to cause a safing action 1 2 2 5 3 Typical operational sequence Set up safety circuit pixel threshold Set up consecutive pixel and frame counts Set s
148. g the UVOT This list is provided for informational purposes These procs should only be run under direction from the UVOT subsystem engineer 2 3 10 UVOT 10 TDRSS HK This procedure describes the steps necessary to turn on and off the downlink of UVOT housekeeping for both the ICU and DPU During L amp EO and possible anomaly conditions during the mission housekeeping may need to be monitored during scheduled TDRSS contacts Swift User Manual Swift UVOT 302 R03 44 2 3 10 1 ICU The proc icu_tdrsshk_on selects how many HK frames up to a maximum of 300 every 10 seconds will be sent to TDRSS This can be terminated prematurely with the proc icu_tdrsshk_off 2 3 10 2 DPU The proc dpu_tdrsshk_on enables copying of HK frames to TDRSS This must be terminated with the proc dpu_tdrsshk_off 2 3 11 UVOT 11 Alert Message Response To describe the alert messages issued by the UVOT Normally there s an internal ICU automatic response to an error See Appendix C The pl p2 and p3 codes usually to be interpreted by MSSL 2 3 12 UVOT 12 Lost Filter Wheel Position This procedure describes the response of the UVOT after a lost filter wheel position During operation the filter wheel may lose its position The recovery is usually autonomous in one of two ways when under the control of one of the many RTSs that are used to control transitions between states and perform Observations see section 1 3 8 2 However they all use the same r
149. he Camera Head BCH is an EEV CCD 02 06 which is a frame transfer device running with a vertical clock rate of 1 67 MHz and a horizontal readout rate of 10 MHz The CCD is of well proven design and is used in many monochrome commercial and scientific TV applications The dummy output from the CCD is subtracted from the video signal to reduce the level of saturation of the final video amplifier stage The main cause of this is clock feed through in the CCD wiring and the reset spike The diagram below shows the functional blocks of the camera Under control from the Blue Processing Electronics BPE the camera is capable of reading out of a number of windows in the CCD image in rapid succession or full 256 x 256 pixel frames The integration time is typically 11 ms CCD 385 576 EEV DARK NOISE CURRENT CLOCK FIXED SUBTRACTION DRIVERS gt DUMMY OUT DIFFERENTIAL IMAGE DATA TO CCD VIDEO AMPLIFIER PROCESSING ELECTRONINS ADC VERTICAL ORIZONTAL REFERENCE including dynamic CCD CCD dark noise current subtraction CLOCK CLOCK SEQUENCER SEQUENCER 1 67MHz 10MHz 60MHz POWER SUPPLY CONDITIONING CLOCK OSCILLATOR CONTROL SIGNALS TO FROM PROCESSING ELECTRONICS Block Diagram of Blue Camera Head Electronics 1 2 2 3 High Voltage Control Unit The High Voltage Control Unit HVU comprises three converters see figure The converters and 2 working in parallel produce the voltage across the MCP1 bo
150. he proc then start icu_safe proc This procedure sends the istate safe which results in the execution of the gotosafe RTS 0x11 This RTS first ensures that any filter movement BPE tables load and HV ramps in progress are terminated the BPE flood LED is zeroed if not already and any DPU exposure stopped The HV Vcathode voltage is set to zero in one step and the camera disabled The filter wheel is then moved to the blocked position and HVs and Vmcp23 are ramped to zero in turn and the HV system then disabled It is possible for the filter wheel movement to fail if for some reason the fine sensor is not detected see section 1 2 3 1 In this case the procedure attempts to recover by moving slowly up to the datum which requires both fine and coarse sensors to be detected and then if that fails the coarse position which only requires detection of the coarse sensor If this occurs for each failure a FW Lost Position and its associated DCS Event Time out messages will be issued Similarly it is possible for the HV ramps to fail with an HV Ramp Failed and its associated DCS Event Time out message if the actual voltage measured does not achieve the requested voltage within the timeout period However the HVs are always disabled at the end of the procedure even if this has occurred but clearly the occurrence should be noted and brought to the attention of the UVOT team It is also important to verify that the
151. hemisphere Within each area the position of each source is stored to half an arc minute accuracy in the RA and declination axes on a 255 by 255 arc minute grid relative to the origin of the area along with each source s associated magnitude information If two or more sources are deemed coincident to half an arc minute accuracy then their magnitudes are combined and the combined information only is stored Each sky area is followed by a CRC value for memory corruption checking It contains 223807 entries Each entry is stored as two words Byte Contents 1 RA offset from the origin of the sky area arc minutes Declination offset arc minutes 2 3 Magnitude code see message table appendix D 5 for codes used 4 Colour index code see message table appendix D 6 for codes used Each sky area ends in a one word CRC value B 2 5 Star Catalogue Addendum The addendum is a 304 word long area of memory which can store up to 100 extra sources At minimum it will consist of a marker to show that there are no more sources stored and the remaining memory zero filled except for the last word which is a CRC value If a source is added to the addendum then it will be put at the beginning of the area and followed by the marker Any new source will not necessarily be added to the addendum if it is coincident with a source already in the main catalogue then its magnitude information can be combined
152. her RTS This is analogous to a subroutine call The arguments supplied may be constants references to the contents of standard memory locations or arguments given to the calling RTS A delay statement This allows a RTS to delay its next action for a number of clock ticks where a clock tick is 0 2 seconds The delay may be a constant a reference to the contents of standard memory locations or an argument given to the calling RTS A wait for event statement This causes the RTS to wait for a specified number of seconds the timeout for a significant event to happen An example of such an event is the successful completion of a filter wheel rotation to a commanded filter position If the event has failed to occur by the end of the supplied timeout the RTS could for example shut down and replace itself with another RTS using the chain statement see below A chain statement This is effectively an unconditional wait for event with zero as the value for the timeout It is used to shut down the current RTS and run a complete replacement Flow control statements The if then else repeat until and while constructs are supported Blocks of statements are conditionally executed depending on the values of certain Boolean flags maintained by the underlying Ada code For example it is possible to respond differently if the instrument is in the SAA or when the wait for event statement described above exceeds its time limit Th
153. in the form of events in which the x and y co ordinates are replaced with the m and n values The two 256 by 256 pseudo images thus formed can be used to calculate a new sub pixel channel boundaries from which the centroid lookup table can be reloaded Note that a modes 4 and 5 are equivalent and both formats are transmitted at once b the first X M N event for each frame is not transmitted Modes 6 or 7 give event height leading to a 1D image i e a histogram They also produce event energy records in which the energy value is set to zero due to this feature being removed from the design Therefore all records of this format should be ignored Note that mode 6 and 7 are equivalent and both formats are transmitted at once In addition there are two words of all zeros the frame tags transmitted at the start of each frame These are used for frame counting and timing purposes This feature can be disabled via the ICB but defaults to enabled A height threshold set via the ICB is used to select valid events This value should be set lower 12 for engineering data to obtain a full pulse height distribution Otherwise a value 15 should be used When following a command integration is enabled data is sent on to the DPU at the start of the next frame pu 0 105095 uonisod sjeubis J041u02 elep 891 01 01 U09
154. ion brightest stars in the sky 99 of all stars with mag lt 11 0 and 90 of all stars with mag lt 11 5 are included Observation data from the ESA Hipparcos satellite provides the catalogue positions and magnitudes Information about the 2 catalogue ref The Tycho 2 Catalogue of the 2 5 Million Brightest Stars Hog E et al lt Astron Astrophys 2000 gt can be found on the Tycho homepage http www astro ku dk erik Tycho 2 For convenience Tycho 2 was subdivided into 3 processing chains Chain 1 contains all stars in Tycho 2 with a lt 0 18 down to a V of lt 11 25 and b gt 0 18 down to a V of lt 10 25 The V and were converted to Johnson magnitudes Chain 2 contains all the stars in Tycho2 with B V lt 0 35 in the range 11 25 lt V lt 12 0 The V and B were converted to Johnson magnitudes Chain 3 contains all the stars in Tycho2 with either B or V not given and the remaining V lt 12 0 If V was missing V was set to B 0 3 If B was missing B was set to V 0 3 Finally V and B were converted to Johnson magnitudes GCVS III The General Catalogue of Variable Stars lists coordinates maximum light magnitude and minimum light magnitude for over 28 000 variable stars in the Milky Way The maximum magnitude in the V and B light has been retained in the Swift catalogue ref Kholopov P N editor et al The General Catalogue of Variable Stars 4th Ed
155. is issued when the ICU has detected that the channel boundaries supplied by the DPU are invalid 1 is always set to Oxffff p2 and p3 to zero 41 BootCmplt No error event code displayed This DPU event message is forwarded via the ICU immediately after the DPU has completed the boot process For full details see ICD for the ICU DPU Protocol for the 42 ChnBndClc No error event code displayed This DPU event message is sent to the ICU to inform it of the channel boundaries produced in the Channel Boundaries Engineering mode For full details see for the ICU DPU Protocol for the C 43 DPU Inconsistent APID ID 34 hex All message packets received by the ICU from the DPU should have an of the form 0x380 y and contain a Message Identifier field of the form 0x0C00 z where y should be equal to z This major anomaly message is issued of this is not the case Both y and z should be the function code of the message and therefore should be in the range 0 gt 255 Swift User Manual Swift UVOT 302 R03 C 10 1 APID received P2 Message Identifier received 0 The ICU response is detailed in the Errors Action Table appendix B 8 C 44 DPU Incorrect 32 hex All command packets sent to the DPU from the ICU should be acknowledged with an ACK or NAK message This major anomaly packet is issued when an ACK is received but its function code field does not contain the functio
156. its conditions and take an appropriate recovery action It needs to protect the instrument during any loss of spacecraft attitude It must recover from any command failures It should respond quickly to an emergency shutdown warning from the spacecraft It is a project requirement that the code will need to run continuously for at least 72 hours without ground intervention It was anticipated that the optimal form of control of the UVOT for both science exposures and for handling or recovering from conditions that involve detector safety issues might not emerge until late in the development and test program It may also change during the course of the mission in order to accommodate changes in ideas and circumstances Therefore the design attempts to be as flexible and readily re configurable as possible 1 3 4 Constraints on Observing There are a number of reasons why it is impossible to perform a sequence of exposures continuously on either automated or planned targets There are pointing constraints imposed by the Sun Moon and Earth Each of these very bright and therefore potentially damaging sources has an avoidance angle constraint stored in EEPROM to which the satellite must adhere The Swift Observatory will be in a low Earth orbit with an orbital period of approximately 96 minutes Assuming no additional pointing constraints imposed by the current position of the Sun or Moon the Earth s avoidance angle implies that it will not
157. l A 1 HV Ramp A 3 4 Limit Check A 3 Appendix B Detailed Description of EEPROM B Located Tables B 1 Location in Memory 1 B 2 Catalogue B 2 Command Database B 6 B 4 RTS Index B 7 B 5 RIS Database 8 B 6 Configurations 9 7 Configurations 11 8 Errors Action Table B 13 B 9 PT Configuration ID Table B 16 B 10 Count Rate Table B 17 Swift User Manual Swift UVOT 302 R03 11 12 13 Avoidance Angle Table State Change Table Standard Table Appendix C Error and Event Messages C2 3 C4 C5 7 8 9 10 11 12 13 14 15 C 16 C 17 C 18 C 19 C 20 C 21 C 22 C 23 C 24 C 25 C 26 C 27 C 28 C 29 30 C 31 C 32 Overview 5 ACS Packets Missing 8f hex Ada Exception ec hex Already at Requested HV 15 hex Angular Constraint Violation 54 hex Automatic State Trans n Req d 53 hex Bad Data in EEPROM 93 hex Bad Value 8e hex BATGRBFLUXINFO Proc Stat 58 hex Boot Dump Report SID d9 hex Bright Object Present 46 hex Bright Star Report SID da hex Bright Star Store Exhausted 4f hex Busy 82 hex Catalogue Star dc hex Centroid Table Already Loaded 5e hex Centroid Table Load Aborted 6e hex Centroid Table Load Failure 64 hex Centroid Table Load OK 63 hex Corrupted EEPROM Data 92 hex Count Rate too High dd hex DCS Aborting 70 hex DCS Call Depth Exceeded 74 hex DCS Event Time out 81 he
158. ll aspects of the UVOT operation It is therefore powered on before and powered off after the telescope module TM see section 1 2 for a description of the TM IMPORTANT SAFETY NOTE If the DEM is powered off with the telescope module TM on the TM will remain in the same state and if that was observing with the high voltages at maximum this loss of control of the TM could result in damage to the detector Should this occur only the SACSLEWSAFEREPLY handshake with its lack of response from DEM as part of the slew warning sequence see section 1 3 11 4 could help as the S C would then power off the TM 1 1 1 ICU 1 1 1 1 ICU Overview The ICU is responsible for controlling and managing all aspects of the UVOT s operation including Interacting with the spacecraft to ensure instrument safety during slews Autonomous instrument safing in off nominal observatory conditions Emergency communications via the Tracking and Data Relay Satellite System TDRSS Autonomous protection of the detector from fields containing bright stars this uses the combination of an on board star catalogue and signals from a bright source detecting safing circuit Interacting with the Figure of Merit computer to select and execute appropriate science observations Control and monitoring of instrument thermal state mechanisms and detector system ICU capabilities are implemented via a combination of compiled Ada code and a customized interp
159. m that defines an on off ratio The power developed is a function of the square of the current spacecraft voltage This algorithm is disabled by default see section 2 5 4 4 This heater is used to shorten the separation of the primary and secondary mirror NOTE that therefore this heater and the metering rod heaters will not be powered at the same time during normal operation This is done using an open loop algorithm that defines an on off ratio The power developed is a function of the square of the current spacecraft voltage This algorithm is disabled by default see section 2 5 4 4 Swift User Manual Swift UVOT 302 R03 23 1 3 ICU SOFTWARE 1 3 1 Overview This section describes the software components resident in the Instrument Control Unit ICU that are responsible for the autonomous control of exposures and for maintaining the health and safety of the instrument All ICU resident code described is written in Ada except when speed requirements dictated assembler The diagram summarizes the electronic architecture of the UVOT The ICU controls and monitors the telescope module TM via the instrument control bus The TM contains the Telescope Module Power Supply TMPSU that controls a a filter wheel the position of which is monitored by LED illuminated sensors b the heaters and c a beam deflector that switches the optical path between the prime and redundant halves of the instrument The Detector Processing Electronics
160. mine which command was rejected C 67 HV Ramp Aborted 12 hex This event message is issued when an HV ramp is aborted by command The parameters are the same as for the HV Ramp Failed message in appendix C 68 C 68 HV Ramp Failed 10 hex This error message is issued when an HV ramp fails The parameters are as follows P1 HV Channel code see HV Channel Code Table D 13 in the Message Codes appendix P2 Target Voltage in hex The ICU response is detailed in the Errors Action Table see appendix B 8 C 69 HV Ramp Succeeded 13 hex This event message is issued when an HV ramp succeeds The parameters are the same as for HV Ramp Failed C 70 ICB Error 60 hex This verification error message is issued when a direct read or write to the telescope module via the ICB instrument control bus has failed due to an error on that bus The APID and Function Code returned should be used in conjunction with the Command Table D 2 in the Message Codes appendix to determine which command was rejected C 71 ICB Errs Forced Htr Shut down b1 hex This major anomaly message is issued after the heater control algorithm has made 10 unsuccessful attempts to communicate with the telescope module All parameters are set to zero The heater control task is then stopped The ICU response is detailed in the Errors Action Table see appendix B 8 C 72 ICU Watchdog Trip 90 hex This error message is issued when the ICU hardware watchdog has tripped
161. mmand packets sent to the DPU from the ICU should be acknowledged with an or message This major anomaly packet is issued when an NAK is received P1 Function Code sent 2 0 0 The ICU response is detailed in the Errors Action Table appendix 8 49 Time out 31 hex All command packets sent to the DPU from the ICU should be acknowledged with an ACK or NAK message This major anomaly packet is issued when this does not happen a after 1 second in the case of the Mode command or b for all other commands after 1 second followed by a resend of the command and then another second has passed P1 Function Code sent 2 0 0 The ICU response is detailed in the Errors Action Table appendix 8 Swift User Manual Swift UVOT 302 R03 C 11 C 50 DPU Unexpected ACK NAK 33 hex All command packets sent to the DPU from the ICU should be acknowledged with an ACK or NAK message This major anomaly packet is issued when an ACK or NAK is received by the ICU when it was not expecting one Function Code in ACK NAK message 2 0 P3 0 51 Strt No error event code displayed This DPU event message is forwarded via the ICU immediately before the DPU starts an upload For full details see ICD for ICU DPU Protocol for the C 52 DPU End No error event code displayed This DPU event message forwarded via the ICU immediately after the DPU
162. n code of the command that was sent P1 Function Code sent P2 0 0 The ICU response is detailed in the Errors Action Table appendix B 8 C 45 DPU Invalid or ID 35 hex All message packets received by the ICU from the DPU should have an of the form 0x380 y and contain a Message Identifier field of the form 0x0C00 z where y should be equal to z Both y and z should be the function code of the message and therefore should be in the range 0 gt 255 This major anomaly message is issued if either the APID or Message Identifier is outside the expected range P1 APID received P2 Message Identifier received P3 0 The ICU response is detailed in the Errors Action Table appendix B 8 C 46 Mode No error event code displayed This DPU event message is forwarded via the ICU when all events for a commanded mode have been processed Mode Submode received by the DPU are displayed together with the completion status of NORMAL STOPPED ABORTED or ERROR For full details see for the ICU DPU Protocol for the For full details see ICD for the ICU DPU Protocol for the 47 Mode No error event code displayed This DPU event message is forwarded via the ICU when the DPU is ready to acquire new event data in the most recently specified Mode command For full details see for the ICU DPU Protocol for the C 48 DPU NAK 30 hex co
163. n in order to start the limit checking afterwards the 1imit on command must be sent twice F 5 MSSL 74 BASIC code The watchdog telecommand runs code that has a delay that means it cannot be sent twice in close succession F 6 MSSL 75 BASIC code If the ICU loses DPU heartbeats it gives Ada exceptions after 1 2 days F 7 MSSL 76 BASIC code If the first copy of EEPROM tables is corrupt there s no NHK message to say so F 8 MSSL 77 BASIC code EEPROM reads writes can conflict because they are not mutex protected It is therefore not possible to dump and load at the same time F 9 MSSL NCR 78 BASIC code MEM MANAGER memory dumps increment the task counter once per dump not once per loop F 10 MSSL NCR 79 BASIC code MEM MANAGER reports give the wrong start address when more than a small area of memory is checksummed 11 MSSL 80 BASIC code Threshold is not set to 15 on startup this is only important if the camera is on F 12 MSSL NCR 81 BASIC code If the DPU heartbeat data are suspect they are still used This may not be a problem Swift User Manual Swift UVOT 302 R03 5 F 13 MSSL NCR 82 BASIC code Task accepts have delays which should not be there 14 MSSL 83 BASIC code When the watchdog is tripped to go from safe to basic the NEXT STATE shows SAFE and the current state shows BASIC F 15 MSSL 94 The QM ICU at MSSL had a bit error
164. nience There are three types of ICU messages 1 Event Message that simply indicates that something useful happened 2 Anomaly message that indicates an error usually serious occurred 3 a Verification Error message which may be either an Unsuccessful Acceptance or Unsuccessful Execution These are issued when a command with the indicated APID and Function Code has been rejected or has failed to execute respectively see the Command Table appendix D 2 for a list of the associated APIDs and Functions Codes F C Details of the 0 to 3 associated parameters are given with each message Note the value of the parameters is always displayed in hex Many messages refer to an RTS Relative Time Sequence by number The number and name correspondence in number order are given in the RTS appendix D 1 Each NHK message also has a package code detailing which code module usually an Ada Package issued the message These are listed in numerical order in the Message Codes appendix D 16 The ICU error and event codes are also listed in numerical order in the Message Codes appendix D 14 Some error messages result in the ICU performing an autonomous corrective action This may take the form of running an RTS copying the error message to TDRSS to alert the ground forcing the ICU to stay in the Safe state or a combination of all of these Where applicable details are given with the appropriate error message They are for releas
165. nstrument specialist The capability to directly write or read from the ICB is enabled with the command IICBENABLE ON The capability to directly write or read from the ICB is disabled with the command IICBENABLE OFF Once enabled it is possible to write directly to an ICB port with the command IICBWRITE address address subaddress subaddress datum datum where address subaddress and datum are as described in the table below Similarly once enabled it is possible to poll an ICB port directly with the command IICBREAD address address subaddress subaddress where address and subaddress are as described in the table below The value datum read is returned in a Task Report packet and displayed in the ICBREAD sequence print Its contents are described in the table below o qepeoj 914 soruooo o Aq possoooy 589226 ALL dox B 1 o qeug 5 Al9JeS NASAS AS SS e qepeo WVA noproy ON 0 nopeos IUI VIS oxiq 1ojourojes LS SPORTED sug AW TATA ow juno Iexrd eAnnoosuo MoD LS pe qeuo TonuoD 1030 A ursrueuoopq jesew SIY 1ndino IMINO 15440 do pH
166. o monitors the spacecraft voltage via the ACS records and then adjusts the time of the heater accordingly It is necessary to supply additional parameters Vnom and Varop to quantify this correction TMin VNom Specifies the expected nominal spacecraft voltage Units are 1 100 of a volt TMax VDrop Specifies the voltage drop to heaters Units are 1 100 of a volt The duty cycle is then corrected as follows If Fna Nominal Duty Cycle Corrected Duty Cycle V Spacecraft Voltage Varop Voltage drop to heater Vnom Nominal s c voltage then Vnom Varop V Varop j Swift User Manual Swift UVOT 302 R03 3 HV Ramp This table supplies the calibration coefficients used by the code to control the three high voltage channels Vcathode Vmcp1 Vmcp23 For each channel two sets of calibration coefficients are required On the control side the requested analogue voltage V is converted to a digital value D that is then sent over the ICB to the high voltage control unit The formula used is of the form D MV C The constants M and C are provided by the table Similarly on the monitoring side the digital representation D of the actual analogue voltage achieved is obtained via the ICB The analogue voltage V is then given by V M D C The table supplies the constants and A 4 Limit Check An on board algorithm monitors various safety critical items at all times
167. o power off the UVOT 2 3 3 UVOT 03 Emergency Safing Under normal circumstances a S C problem i e Safehold Mode will place the UVOT into the Safe state In the event this did not occur or a problem is discovered with the UVOT the UVOT subsystem engineer may direct the FOT to execute this procedure Swift User Manual Swift UVOT 302 R03 41 The emergency safe procedure executes RTS 3 As this is identical to the first part of UVOT 2 similar considerations apply As several of the above actions go against the advice given in the above section on safety issues it is clearly advisable to only use this procedure in extreme circumstances The routine power off procedure will normally be used to power off the UVOT 2 3 4 UVOT 04 Power Off and On On rare occasions the UVOT may need to be powered off and subsequently powered back on This procedure should be followed for this purpose Initial power on i e L amp EO will be unique and described in the L amp EO Timeline Script The execution of power on and off should only be done if directed by the UVOT subsystem engineer or after getting concurrence from him 2 3 4 1 Power Off Procedure The uvot_power_off proc will check that the ICU is in Basic or Safe state If neither is true it will request whether you would like to go to Safe If this is declined the proc will exit as it is not appropriate that it continue until it is safe so to do If the instrument is not in Safe of Basic t
168. oadl mid 0 o0ffset 0xb7f lt word offset data value where the items in lt gt are replaced with the relevant values Description Offset TMP SU 0 Temperature Control Circuit Status 0 1 off on Coarse Position Sensor Current range 0 gt 15 BPE ANALOGUE 2 Fine Position Sensor Current range 0 gt 15 3 Vmcpl Nomimal 4 Vmcp23 Nominal HV Nominal Settings volts 5 Vcathode Nominal 6 Vmcpl SAA 7 Vmcp23 SAA HV Settings whilst in SAA volts 8 Vcathode SAA 9 Vmcpl SLEW 10 Vmcp23 SLEW Ca whilst slewing Vcathode SLEW BPE DIGITAL 12 xlow 13 ylow Window configuration defaults 14 xsize to full frame units CCD pixels 15 ysize 16 Channel Boundary 0 Channel Boundaries 17 Channel Boundary 1 range 1000 gt 1000 18 Channel Boundary X2 XO lt lt X8 19 Channel Boundary X3 XO AGNI Sud 20 Channel Boundary X4 21 Channel Boundary X5 22 Channel Boundary X6 23 Channel Boundary X7 24 Channel Boundary X8 25 Channel Boundary YO 26 Channel Boundary 1 27 Channel Boundary Y2 28 Channel Boundary Y3 29 Channel Boundary Y4 Swift User Manual Swift UVOT 302 R03 B 22
169. ocked filter for a colour index of 11 0 68 lt B V lt 0 74 Count rate 100 for the Blocked filter for a colour index of 12 0 74 lt B V lt 0 81 Count rate 100 for the Blocked filter for a colour index of 13 0 81 lt B V lt 1 10 Count rate 100 for the Blocked filter for a colour index of 13 1 10 lt B V 1 49 Count rate 100 for the Blocked filter for a colour index of 15 1 49 lt B V 01 64 2 2 2 2 2 2 2 2 30 2 CN O E NN NEUEN 1 2 3 4 5 7 10 11 12 13 14 15 16 18 19 1 2 3 4 6 7 8 9 1 Swift User Manual Swift UVOT 302 R03 am 32 Count rate 100 for the Blocked filter for a colour index of 16 B V gt 1 64 34 67 Count rates 100 for the filter 68 101 Count rates 100 for the UVW2 filter 102 135 Count rates 100 for the V filter 136 169 Count rates 100 for the UVM2 filter 170 203 Count rates 100 for the Grism2visible filter 204 237 Count rates 100 for the UVWI filter 238 271 Count rates 100 for the U filter 272 305 Count rates 100 for the Magnifier 306 339 Count rates 100 for the B filter 340 373 Count rates 100 for the White filter 374 CRC for entire table Swift User Manual Swift UVOT 302 R03 B 19 B 11 Avoidance Angle Table This table is used to store the avoidance angles used by the ICU to determine if a angular constraint vi
170. of the source see the Magnitude Code Table in the Message Codes appendix D 5 Ang Dist The source s offset from the predicted position rounded up to the nearest minute of arc hex Col Index A code number in hex representing the B V colour of the source see the Colour Index Table D 6 in the Message Codes appendix Sky Area If it has the value 7005 or 7006 hex then this indicates that Uranus or Neptune respectively is in the predicted field of view Otherwise it is a code number in hex representing the individual sky area in the main catalogue containing the source To work out which Convert it to a decimal value Left pad it with zeros to make a 5 digit number Swift User Manual Swift UVOT 302 R03 C 5 If the first digit is 1 it is a southern hemisphere area otherwise it is northern The second and third digits are the declination band see below The fourth and fifth digits are the right ascension division see below So for example 0 04 0 becomes decimal 01216 which indicates sky area north declination band 12 and right ascension division 16 Each hemisphere is split into 22 declination bands numbered 0 to 21 starting from the equator and going to the pole Each band is 255 arc minute wide except for the polar bands which are 45 arc minute wide Any source within half an arc minute of the equator is taken to be in the first band of the northern hemisphere only Each declination band is divided into a number of equal
171. of the stars from the Tycho 2 catalogue gave data in epoch 1991 5 while around 3000 variable stars from the GCVS gave information in epoch 1950 coordinates The right ascension and declination both given in degrees were converted to epoch 2000 0 using these equations new old 15 3600 years 3 074 1 336 sin pi 360 R A old tan pi 360 Dec old Dec new Dec old 1 3600 years 20 038 cos pi 360 R A old years is the number of years between 2000 0 and the epoch given This precession equation produces values accurate to lt 1 second of right ascension and five arc seconds of declination The equation was found an Arizona State University astronomy class webpage http ircamera as arizona edu astr_250 ProblemSets tele_solv html PSEUDO SOURCES Two pseudo sources were added to the Swift catalogue Both of the NGC objects given below are bright over a wide area and cannot be modelled as a source with a single bright core In the Swift catalogue as it stands there is a core source for each object and the following two pseudo sources will effectively extend the objects to give more accurate brightness coverage RA Dec V B Object 140 356 58 307028 10 4 10 1 NGC2867 Swift User Manual Swift UVOT 302 R03 B 3 251 127583 23 799278 9 41 9 11 NGC6210 COMPONENT CATALOGUES TYCHO 2 The Tycho 2 catalogue gives astrometric and photometric and Bu information for the 2 5 mill
172. olation has occurred The units are minutes of arc If the angular separation of the pointing position from the object listed is less than the angle given then a constraint violation has occurred Note the working copy of this table is located in RAM starting at address 0 It is therefore possible to change locations in this table on the fly using the iicuload command e g iiculoadl mid 0 offset 0xa00 lt word offset data value where the items in lt gt are replaced with the relevant values An avoidance angle of zero disables the test Word Description Offset 0 Avoidance angle for Mercury units are minutes of arc 1 Avoidance angle for Venus units are minutes of arc 2 Avoidance angle for Mars units are minutes of arc 3 Avoidance angle for Jupiter units are minutes of arc 4 Avoidance angle for Saturn units are minutes of arc 5 Avoidance angle for Uranus units are minutes of arc 6 Avoidance angle for Neptune units are minutes of arc 7 Avoidance angle for Pluto units are minutes of arc 8 Avoidance angle for Sun units are minutes of arc 9 Avoidance angle for Moon units are minutes of arc 10 Avoidance angle for Earth units are minutes of arc 11 145 Followed by 135 entries similar entries giving the avoidance angles for objects with magnitude codes in the order 0 gt 134 as used in the on board star catalogue see Magnitude Code table D 5 in the Message
173. om the spacecraft and between instruments using a MIL STD 1553 bus This interface is controlled by the Swift 1553 Bus Protocol Interface Control Document Spectrum Astro 1143 519121 also referenced to in this document as the 1553 ICD Device RT Sub 1553 Tranx Data Description Address address Words UVOTDPU 6 11 25 RT Transmit 32 15 Instrument CCSDS Telemetry 26 RT Receive 1 Telemetry Done Indicator 27 RT Receive 31 Instrument CCSDS Telecommand 29 RT Transmit 32 RT to RT Telecommand 30 RT Rev Tx 1 to 32 Data Wrap Around UVOTICU 19 11 25 RT Transmit 32 15 Instrument CCSDS Telemetry 26 RT Receive 1 Telemetry Done Indicator 27 RT Receive 31 Instrument CCSDS Telecommand 29 RT Transmit 32 RT to RT Telecommand 30 RT Rev Tx 1 0 32 Data Wrap Around Swift User Manual Swift UVOT 302 R03 5 The UVOT DPU and UVOT ICU each have a remote terminal addresses on the 1553 bus as per table above It should be noted that the UVOT ICU addresses are identical on both Prime and Redundant halves of the instrument They should therefore NOT be turned on at the same time otherwise 1553 errors and packet loss is anticipated A similar situation exists for the UVOT DPU The spacecraft can accommodate variable length packets in CCSDS packet telemetry format transmitted over the MIL STD 1553 interface However all telemetry packets issued by the UVOT ICU are of fixed length 1
174. ommand should be ignored Ack Acknowledge generated by the sub system data 16bit value to be used by the sub system ICBacquire ICBinstruction ICBdata 1 3 5 13 1 21 22 23 0 3 5 21 22 23 101 ICUaddr dest subaddr 100 011 00 data parjerr ack 3 5 5 5 2 16 1 1 1 The ICU generates the ICB instruction word and the ICBdata word is then generated by the addressed sub system ICUaddr The ICB address of the ICU Dest and subaddr Defines the sub system which should respond to this command Par Parity for the word err Error condition if true during the instruction the command should be ignored if true during ICBdata the response will be ignored by the ICU Ack Acknowledge generated by the sub system in response to the instruction generated by the ICU in response to the ICBdata Data 16 bit value to be used by the sub system The clock frequency of the interface is 512 Hz Swift User Manual Swift UVOT 302 R03 7 1 1 3 4 Time The ICU has two 1 inputs and The two Ipps signals are both on but a software controlled switch in the ICU selects between and B Interrupts are generated once per second in the ICU from the selected I pps signal Onboard time is managed using two components spacecraft clock and a UT correlation factor UTCF spacecraft clock is the spacecraft s internal clock used for th
175. on All subsequent states are supported only by the operational code There are a number of NCRs on this code see Appendix F MSSL NCR 22 MSSL NCR 74 MSSL NCR 75 MSSL NCR 76 and MSSL NCR 77 As this code is ROM based they cannot be fixed OPERATIONAL CODE ONLY Safe As its name implies in this state the instrument is configured to be least susceptible to damage The safety features that were performed in Basic are repeated i e the filter wheel is set in a blocked position and the high voltages HVs are set to zero This is because we may return to this state without going through Basic state It maintains housekeeping on board autonomous limit checking thermal control and enables the watchdog see section 1 1 1 5 These latter processes continue to run in all other states of the operational code Idle The UVOT is configured to be ready to observe but is awaiting the next slew As a safety precaution the cathode voltage is held down at zero and the filter wheel may be placed in the blocked position until observations commence Slewing In this state the UVOT cleanly shuts down any current observation prepares the instrument for slewing and informs the spacecraft when it is ready As a safety precaution the cathode voltage is held down at zero It then selects the next exposure and performs various safety calculations Settling After a new GRB has entered the UVOT s field of view but before the spacecraft has settled it is ob
176. ontrol code This is a optional modification to release code space for additional modifications F 29 MSSL ECR 195 Remove bright star avoidance code This is a optional modification to release code space for additional modifications 30 MSSL ECR 196 Swift User Manual Swift UVOT 302 R03 F 7 Remove twilight zone code This is a optional modification to release code space for additional modifications F 31 MSSL ECR 198 Remove beam steerer code This is a optional modification to release code space for additional modifications F 32 MSSL ECR 199 Remove the code to remove the optional axis flips when calculating the XRT pos shift This is a optional modification to release code space for additional modifications F 33 MSSL ECR 202 The diagnostic rts line should be removed as it is never used This is a optional modification to release code space for additional modifications F 34 MSSL ECR 207 In order to facilitate ground analysis of ATs the Ada code should be modified such that a single image exposure in 1 filter can be replaced by multiple shorter exposures in the same filter contiguously F 35 MSSL ECR 208 Allow 2 lines of settling exposure definitions If the first is too bright and shortened to less than 10s it falls through the next filter but if it is greater than or equal to 10s it does only that exposure
177. or Codes in Numerical Order appendix D 14 table in the Message Codes appendix P3 the first parameter of the associated error as this is often used in conjunction with P2 to determine which RTS to run C 93 Safety Circuit Alert 5a hex This major anomaly message is issued when an attempt is made to configure the safety circuit when it is not safe so to This usually happens after the safety circuit has tripped and a safety circuit configuration is attempted before going to the safe state The ICU response is detailed in the Errors Action Table see appendix B 8 94 SC1553 Dump Report SID 48 hex This error message may be used in the future to give a memory dump of important 1553 registers following an error Note this message is currently not used C 95 SC1553 Read Error 8 hex This error message is issued on encountering an error when reading 1553 messages telecommands P1 Error code P2 5 1553 ERROR error counter from interrupt handler P3 SC1553_INTERRUPT pending interrupt register The ICU response is detailed in the Errors Action Table see appendix B 8 C 96 SC1553 Startup Error 89 hex This error message may be used in future releases to indicate as starting up error in the 1553 Note this message is currently not used 97 SLEWABORT Received 59 hex Swift User Manual Swift UVOT 302 R03 C 17 This major anomaly report indicates that a SLEWABORT message was received from the spacecraf
178. ord e Safe Hold flag being set to true in the SISCATTITUDE record The table consists of a series of records one for every current state next state combination Each record has the following format Unless stated otherwise values used in the table are 0 false 1 true 255 Don t Care The records are ordered by first the numerical values of Current State and then Next State Description Category 0 Current state see table D 8 State informatici 1 Next state see table D 8 2 Out of safe enabled 3 AT observations enabled Whether vanes 4 PT observation enabled 5 Safepoint Observations enabled 6 Autonomous transition allowed 7 In SAA 8 Within 10 Arc Min Information derived from 9 Settled the ACS record 10 Power Down Safe 11 NEW AT SLEW Derived from the 12 AT PT SAFEPOINT 0 1 2 FONEXTOBSINFO 13 Slew warning received 14 Finding Chart acquired or abandoned 15 RTS no action not allowed RTS code see table D 1 0 0x7ffe RTS to run Swift User Manual Swift UVOT 302 R03 B 21 B 13 Standard Table This table contains a miscellany of numerical values describing various systems that do not readily belong in the other tables Note the working copy of this table is located in RAM starting at address Oxb7f It is therefore possible to change locations in this table on the fly using the iicuload command e g iicul
179. pendix B 7 containing incorrect data 1 UVOT Mode P2 PT configuration ID i e the label of the first exposure for which the condition was detected C 108 Unacceptable Absolute Drift 4d hex This error message is issued when a target position has been specified earlier e g in a FONEXTOBSINFO message and we are settled but we have drifted away from that target position by more than the expected absolute drift The standard on board table appendix B 13 specifies the acceptable level of absolute drift P1 the drift detected expressed and rounded up to the nearest minute of arc hex P2 the current RA expressed and rounded up to the nearest minute of arc hex P3 the current DEC 100 degrees rounded up and expressed to the nearest minute of arc hex The ICU response is detailed in the Errors Action Table see appendix B 8 C 109 Unacceptable Diff ntial Drift 4c hex This error message is issued when we are settled and the drift between successive monitored attitude packets has exceeded the expected relative drift The standard on board table appendix B 13 specifies the acceptable level of relative drift P1 the drift detected expressed and rounded up to the nearest minute of arc hex P2 the current RA expressed and rounded up to the nearest minute of arc hex P3 the current DEC 100 degrees rounded up and expressed to the nearest minute of arc hex The ICU response is detailed in the Erro
180. protected 1 3 9 2 Planetary Positions In order to protect the instrument from moving celestial object damage the ICU calculates the positions of the Sun Earth and Moon as a backup to the protection already provided by the spacecraft In addition similar calculations are performed for Venus Mars Jupiter Saturn Uranus and Neptune as the spacecraft does not provide this information All target fields of view are compared against these positions and an EEPROM located table of angles of avoidance Any violation of those angles prevents the exposure except in the cases of the fainter planets Uranus and Neptune which are considered as stars of the same colour index as the Sun and a maximum observing time deduced instead The ICU calculates the Sun Moon and planetary positions on startup and every slew The checks for constraint violations of the Sun Earth and Moon are made every two seconds The planets are checked for constraint violations every slew Swift User Manual Swift UVOT 302 R03 32 The positions are calculated using formulae algorithms and data given in 1 U S Naval Observatory The Astronomical Almanac Government Printing Office 2001 2 Kenneth Seidelmann Editor The Explanatory Supplement to the Astronomical Almanac University Science Books 1992 3 Peter Duffet Smith Practical Astronomy with Your Calculator 374 Edition Cambridge University Press Cambridge 1979 4 Jean Meeus Astronomical Formulae for Calcul
181. r not used h_12 12 32767 Placeholder not used h_13 13 32767 Placeholder not used h_14 14 32767 Placeholder not used h_15 15 32767 Placeholder not used 2 32767 Implemented in Ada rather than RTS Causes transition to Basic state Implemented in Ada rather than RTS Performs emergency fast h_emergency_safe 3 32767 transition to Safe state HVs slugged to zero filter wheel to datum Implemented in Ada rather than RTS Requests s c to turn off Tf 32767 UVOT Telescope Module 5 32767 Implemented Ada rather than RTS Requests s c to turn off UVOT Ramps up Vmcp23 and Vmcp1 to nominal see diagram is 231 1933 m section 1 2 2 4 for definition of voltages 1032 101 up Vcathode to nominal see diagram is section 1 2 2 4 for definition of voltages Ramps down Vcathode to zero then if we are in the SAA hvidle_or_saa 1031 101 ramps down Vmcp23 and to SAA levels see diagram is section 1 2 2 4 for definition of voltages Ramps up Vmcp23 1 Vcathode to nominal see ns a diagram is section 1 2 2 4 for definition of voltages Ramps down Vcathode Vmcpl and Vmcp23 to zero see ff b HET i diagram is section 1 2 2 4 for definition of voltages HVs ramped down quickly Vcathode set to zero other HVs hvofffast 1030 101 ramped down in 5 seconds each see diagram is section 1 2 2 4 for definition of voltages hvon 1026 100 Not used hvsaa 1029
182. r from bright source damage 1 If the star is within an EEPROM tabulated angle of avoidance around the field of view for that magnitude observation of that field of view is prohibited This prevents stray light for example reflected off the baffle entering the optics There is an outstanding NCR on the code associated with this table see Appendix F MSSL NCR 117 whereby 2 very bright stars may not be avoided by the distance required Due to a change and lowering of the avoidance angle acceptable for these stars this has proved not to be a problem 2 If the star is in the field of view and does not violate any angle of avoidance criteria its colour is used to index into a table giving the theoretical count rate as a function of filter The colour index is a B V magnitude The count rate is then scaled by the catalogued magnitude The count rate for each star thus calculated is used to decide how long if at all an observation at a particular pointing in that filter can safely continue and the worst case used of al the stars used The count rate deduced is used in 3 ways If the count rate exceeds tabulated value in the standard table area see Appendix 3 6B 13 star is not observed at all b If the total counts would exceed a tabulated value in the standard table area see Appendix 3 6B 13 the exposure is reduced in time so that value is not exceeded c Ifthe reduced value of the exposure time falls below
183. r priority RTSs Checks are first performed that no ICU s w condition precludes such a transition that the safety circuit is not on alert and that there is no sun moon or earth constraint violation The mechanism excessive temperature protection circuit DISMON is enabled and the values of the coarse and fine sensor illumination LEDs are set to their EEPROM tabulated values A failsafe attempt to move the filter wheel to blocked position is performed It is possible for the filter wheel movement to fail if for some reason the fine sensor is not detected see section 1 2 3 1 In this case the procedure attempts to recover by moving slowly up to the datum which requires both fine and coarse sensors to be detected and then if that fails the coarse position which only requires detection of the coarse sensor If this occurs for each failure a FW Lost Position and its associated DCS Event Time out messages will be issued and the RTS will switch to an alternate RTS that will return the UVOT to safe The Vmcp23 and then HV values are then ramped to 70 of their final values These values are suitable for the SAA and are a precaution in case the SAA is encountered during the Safe to Idle transition It is possible for the HV ramps to fail with an HV Ramp Failed and an associated DCS Event Time out message if the actual voltage measured does not achieve the requested voltage within the timeout period Should this occur the RT
184. rd uoyym 1 03308 AITenueur ayes ut jou dico v xur A eae 71 HO sr LOAN WY pue 4 5 1 1510 01 YUT aed ayes 9uo8 sey NOJ WY psdD Z LOAN wozu 1 aNs SLOAN apo 2 5 oq YOTYM soSessour LOAN oje8nsoAu LOd uonisiboy 9 LOAN 1 pou MOTPA pou JUULI Fre LV O COC LOA T13JIAS Tenue PSN IIMS eyeansoAu LOAN N oq yorym soSessour LOAN oje8nsoAu L Od Aga SANV LOAN WOJU 104 i And LOAN 1 AS 184 Jo dog 10 uo Jamod LOAN Suunp ewou SUOTRIOIA 930N 38e IOA eos 210 joan 110 joan 12816 pue 4 suoisinoxo oAnnoosuoo 110 119146 pue MOT O 4 pue LOAN Imod LOA
185. reted scripting language the RTS system together with EEPROM located tables of exposure sequences safety related information and calibration data 1 1 1 2 PROM The PROM contains a bootstrap that on power up or reboot copies the basic set of code from PROM into RAM and executes it The basic code supports basic safing of the instrument provides housekeeping and thermal control initiates the loading of operational code into RAM for execution and permits updates to the operational code 1 1 1 3 EEPROM EEPROM A contains the operational code and tables required by the basic code EEPROM B contains all remaining tables the star catalogue and the RTS scripts see later sections for descriptions of the star catalogue and the RTS system 1 1 1 4 RAM RAM consists of 64K words of code space and 64K words of data space A 31750 word consists of 16 bits 1 1 1 5 Watchdog The ICU watchdog timer gives a timeout after 11 seconds If the timer reaches zero a power down interrupt is generated and 25615 later the ICU will be reset This timer is disabled on power up and is enabled by ICU software The timer can be enabled and disabled by ICU software This timer is reset provided the ICU hardware and software is working normally The reset period is commandable On a less frequent but also commandable time interval the counter is reset provided aliveness flags maintained by all software tasks in the ICU are being continuously reset by those tasks
186. riate description within the database Each command block has the following format Word Description Offset 0 Overall length of block in words including itself and CRC 1 Command Code gt APID and Function Code see note below for format details 2 Number of Fields NF i e command parameters may be zero 3 Value in Packet Length Field in final command Followed by NF occurrences of a three word block describing the location and size of the each field in the same order as the fields in the command 0 Starting word 0 is first word in packet 1 Starting bit within word 0 is most significant 2 Field length in bits Followed by 0 CRC Note The Command Code word offset 1 has the following format MSB LSB 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 APID Band APID Offset Function Code Band converts to Base as follows The command is then constructed by adding Base to APID Offset APID APID Band Base 0 0x600 1 0x620 2 0x640 3 0x660 4 0x680 5 0x700 6 0x700 7 0x700 Swift User Manual 4 RTS Index Swift UVOT 302 R03 This is used to determine the start address for a particular RTS located in the RTS Database area The index is divided into NHASH sections numbered 0 through NHASH 1 An RTS belongs in section n
187. rnal stop commands are processed The corresponding commands to start them again are ihtron ilimiton and ihkon respectively Note that as a task make be in the suspended state it will be necessary to issue the relevant start command twice to ensure it will start SRRA d lda CX 7 Mop YY TED 777 aor 4 Niele a n c6 9 he 21 WC MAL CXI C6 G o Gt meo Har Dar d 2 4 AN wu E MET YXA X3 Soe BI ees Poh 5 M ps Wiles F BI 0 tag 14 IM 97 XA TARR Pe sed BUS iXX X Urs c WEST ke 3 d ST 24 e 8 SEM 23 3 wees Yr E 148 E e LIT a 1 53 AY TA 4 neZ 6 FAT et lee lt Myr A watt Awe EX gt of comparo Sees IKE JOVAYSLNI ih ort OH A OD MAONI X 991 al 127 94 42
188. ror Handling tables for revision 10 Modified DCS Event Table ECR 205 Documented NCR 22 NCR 74 82 NCR 94 and NCR 117 Updated list of RTSs for revision 10 Added error codes to the errors messages section Added example images of coincidence loss and excessive count rates to detector section Loading or dumping memory at the same time warning Section 2 4 Section 1 2 2 4 Section 1 3 Appendix A Appendix E pp gt section 1 3 7 Section 1 3 8 2 Appendix C Section 1 2 2 Section 2 5 3 Swift User Manual Swift UVOT 302 R03 ACS AT BA BPE CDS DCI DEM DPU DTAS EDT EEPROM EF EST FOT F W GSFC HK HV HW ICU L amp EO MOC MSSL NFI NHK OAB OB ODS PROM PSF PSU QA RF RTS SAA S C SDC SERS SOT TBA TDRSS TM UDS UIM UVOT ACRONYM LIST Attitude Control System Automatic Target Burst Advocate Blue Processing Electronics a k a the Detector Electronics Calibration Data Specialist Data Capture Interface Digital Electronics Module Data Processing Unit Data Trending amp Analysis System Eastern Daylight Time Electronically Erasable PROM Early Frequency Eastern Standard Time Flight Operations Team Filter Wheel Goddard Space Flight Center House Keeping High Voltage Hardware Instrument Control Unit Launch amp Early Orbit Mission Operations Center Mullard Space Science Laboratory Narrow Field Instrument Non Periodic Housekeeping Osservatorio Astronomico di Br
189. rs Action Table see appendix B 8 C 110 Undefined State Transition 40 hex This event report should only be issued as a diagnostic It occurs when a deliberate attempt is made to run the RTS whose code is designated as undefined and therefore would normally not be run by the ICU There are no associated parameters C 111 Unexpected IsSettled Flag Off 50 hex This error message is issued when the ICU detects that the settled flag in the ACS record has changed to false without a preceding SISLEWWARNING message There no parameters associated with this message The ICU response is detailed in the Errors Action Table see appendix B 8 C 112 UVOT Mode Exhausted 49 hex This event message is issued at the end of a sequence of PT exposures associated with a requested UVOT Mode when there is time left before the next slew P1 is set to the UVOT Mode C 113 Watchdog Reports a Task Hang ed hex This error message is issued when the watchdog task detects that another ADA task has been inactive for some time P1 Task Identifier see Task Identifier Table appendix D 12 in the Message Codes appendix Swift User Manual Swift UVOT 302 R03 C 19 C 114 Window Table Already Loaded 5f hex This event message is issued when the parameters of a load window table command are the same as the on board record of what was last loaded The table load is therefore suppressed There are no parameters associated with this message C 115 Window
190. rying spacecraft voltage The algorithm therefore monitors the spacecraft voltage via the ACS records and then adjusts time of the heater accordingly It is necessary to supply additional parameters Vnom and Vdrop to quantify this correction The duty cycle is then corrected as follows If F Nominal Duty Cycle Corrected Duty Cycle V Spacecraft Voltage Varop Voltage drop to heater Nominal s c voltage Swift User Manual Swift UVOT 302 R03 60 then F Fn Vnon7 Varop V Varop 2 Number Specifies which heater Values are 3 ZMETERING RODS or 4 SECONDARY MIRROR OnTime Specifies the nominal on time with the cycle Units are 1 10 second A value of zero disables that heater NOTE no more than one of the focussing heaters should be enabled If both are enabled the algorithm ignores heater 4 CycleTime Specifies the cycle time Units are 1 10 second TMin Vnom Specifies the expected nominal spacecraft voltage Units are 1 100 of a volt TMax Vdrop Specifies the voltage drop to heaters Units are 1 100 of a volt NumThermistors Ignored should be set to zero Therml Ignored should all be set to zero Therm2 Therm3 2 5 5 Direct Control and Monitoring of ICB Ports NOTE these commands are used for diagnostic purposes only They are potentially dangerous since they bypass all protections in the on board code They should therefore only be used under the supervision of the UVOT i
191. s then enabled 2 3 5 UVOT 05 Recovery from Safehold When the S C enters Safehold mode the UVOT will be placed via RTS into one of three states a Safe State b Only TM Powered c UVOT Powered Off In all cases before returning the UVOT to normal the operations team should contact the UVOT subsystem engineer Together they should verify that the cause of the entry into Safehold is understood and the UVOT can safely be returned to normal operations 2 3 5 1 Recovery from Safe State NOTE Until NCR 114 is fixed see ICU software NCRs and ECRs Appendix F the transition safe to idle should not be performed if there is a risk we may enter the SAA during that long transition The icu idle proc checks appropriate prerequisite conditions before commanding to idle state The first check is that no Sun Earth or Moon constraints are being violated This is followed by a request to reset the safety circuit if required Two of the checks can be bypassed if the s c is not settled and there is less than 300 seconds to the next slew However this should only be done if directed by the UVOT subsystem engineer The sa e to idle RTS 0x31a initiated by the istate idle command performs the necessary sequence of actions to ready the UVOT for observation and leaves it in the idle state It runs at slightly higher than the normal priority to ensure it is not interrupted other than by urgent or safety requests which lead to the initiated of highe
192. se 10 RTS Name Code Priority Description ee ee 19 1000 ie aa ICU to autonomously decide and switch to the next Moves filter wheel to blocked position transitions to Idle or blocked_failsaf 2 d SAA state if s c present in SAA with HVs set accordingly blocked tdrss 1284 1000 Same as blocked failsafe but also issues TDRSS message bright planets 1007 0 Not used Pokes locations in ICU Ram with state code and issues NHK change state 513 0 message to say State Change has taken place Contingency RTS Goes to Safe state then requests S C to 257 3765 turn off UVOT Contingency RTS Goes to Safe state then requests the S C to iU d tmoff ene seers om oe turn off UVOT Telescope Module only diagnostic 1280 0 Diagnostic RTS Sends NHK event message with supplied 3 parameters inserted into it 48 0 Starts exposure using start exp waits for exposure length plus DPU slack then ends exposure using end_exp Performs finding chart exposure If allowed to go to do_f gt 1000 completion flags that the finding exposure has been achieved Gis 1014 1000 Performs Planned Target exposures including Null or Idle type exposures Runs during slew Allows any centroid table load to complete do_slew 770 1000 Switches to appropriate exposure at start of settling settled period do cane 1011
193. served by collecting an event list As the target will be moving rapidly it is not possible to collect an image Finding Chart If the target is a new then once the spacecraft has settled a 100 second exposure is made in a standard filter to produce a finding chart that will be sent to the ground In many cases by the end of the exposure the XRT will have reported an improved position for the source The ICU uses that information and the GRB brightness information supplied by the BAT when it configures for the subsequent Automated Target exposures Automated Target AT During the period whilst a GRB has no pointing constraints this is referred to as a snapshot the ICU will configure and run a series of exposures in this state Planned Target PT The ICU will configure this type of exposure when the FOM informs the ICU via the FONEXTOBSINFO record that the spacecraft is performing a planned observation Safe Pointing SP The ICU will configure this when informed that the spacecraft is slewing to a safe pointing This type of exposure occurs when no automated or planned targets are available South Atlantic Anomaly SAA In this configuration the instrument is configured to be safe whilst passing through the SAA In particular the MCP bias voltages are held at 7096 of their nominal value and the cathode voltage is at Zero Swift User Manual Swift UVOT 302 R03 34 1 3 11 Observing Sequences This section illustrates
194. spect to this offset and do not therefore follow this even odd requirement For each pair of CCD rows there is a location in the RAM containing a row action code This will specify what to do with the row pair as a whole The values and meanings are Perform vertical transfer only i e no horizontal readout This is used for skipping unwanted rows Readout the row ignoring window IDs thus dumping unwanted charge build up Readout the row taking note of window Ids and transmitting the event data to the DPU Complete horizontal readout and skip to the start of frame transfer i e skip to end The table is loaded from the ICU via the ICB 1 2 2 6 3 Centroid Lookup Centroiding is the process of locating the position of an event to accuracy greater than that of a CCD pixel For each event and in both the x and y axes the processing electronics produces two 8 bit numbers labelled m and n The division m n is the fractional position within a CCD pixel of the event The range is divided into 8 bins otherwise known as sub pixels Rather than performing this calculation there are two 64k by 4 bit tables containing all possible results of the division The m and n are combined into a single 16 bit address that is used to lookup the result The result is in the range 0 7 Preparing the table contents requires two sets of 9 channel boundary values giving the edges of the sub pixels in both x and y They are in th
195. ssued when a different part of the time calculation overflowed P1 Variable TIME TEMP high word P2 Variable TIME TEMP low word 0 C 104 Timesync Too Late 23 hex This error message is issued when the flight software was too slow or busy causing the time code to miss time synchronization or the TIMETONE and I pps arrived at the wrong times 0 8888 P2 Variable SECONDS high word P3 Variable SECONDS low word The ICU response is detailed in the Errors Action Table see appendix B 8 C 105 Timesync Too Long Since 22 hex This error message is issued when there has been no for more than two s Swift User Manual Swift UVOT 302 R03 C 18 Seconds since last 1pps P2 SYNCHRONIZE_ME time sync status variable 0 C 106 Too Many Cts Report SID db hex This message is issued to indicate that in the predicted field of view the theoretical accumulated counts on the described source have reached a maximum limit This usually precludes observing as the maximum exposure time is set to zero The format of this message is non standard The fields are the same as the Catalogue Star message C 107 Total Exposure Time Is Zero 55 hex This error message is issued when the ICU whilst trying to scale a series of PT exposures to a snapshot length detects that the total length of the exposures to be scaled is zero seconds This is usually caused by the PT exposure configurations table ap
196. t All parameters are set to zero C 98 SSI Error c1 hex This error message is issued on encountering an error on the SSI interface P1 Error code 2 0 0 The ICU response is detailed in the Errors Action Table see appendix 8 C 99 State Transition Complete 41 hex This event message is issued when the ICU successfully transitions to a new state defined by 1 see state table appendix D 8 in the Message Codes appendix P2 and P3 are set to zero C 100 Switching RTS 78 hex This event message is issued as an RTS shuts itself down in favour or another RTS given by see RTS table appendix D 1 in the Message Codes appendix P2 and P3 are set to zero C 101 Timesync Jump 25 hex This error message is issued when the Spacecraft time or Mission Elapsed Time MET has jumped forwards or backwards by more than about 1s P1 MET at last sync seconds first word P2 MET at last sync seconds second word P2 MET at penultimate sync seconds second word The ICU response is detailed in the Errors Action Table see appendix B 8 C 102 Timesync Overflow 24 hex This error message is issued when part of the time calculation overflowed P1 OxFFFF P2 MET Mission Elapsed Time at last sync seconds first word P3 z MET at last sync seconds second word The ICU response is detailed in the Errors Action Table see appendix B 8 C 103 Timesync Too Big 21 hex This error message is i
197. t UVOT 302 R03 D 16 PACKAGE CODES IN NUMERICAL ORDER Note on the ITOS icuevents window only the 2 most significant digits are displayed as the last 2 are always zero Package D 26 Swift User Manual Swift UVOT 302 R03 CRC 0xC200 CHCKSUM 0xC500 STARCAT COMMAND_DISTRIBUTOR DPU 0 DETSAFETY 0 500 DETANALOG OxDAOO DEBUG DCS DETDIGITAL _ 0 500 OxEE00 Swift User Manual Swift UVOT 302 R03 1 Appendix Telecommands Telecommand Summary in Alphabetical Order Note naming convention used means that the commands are listed in sub system order The third column indicates its support in basic NAME Description FONEXTOBSINFO Info about next target to be observed IBATGRBFLUXINFO BAT GRB flux info IBPEACOMODE Set BPE Acq Mode IBPECAMERA Enable Disable Camera Running IBPEFRAMETAGS Enable Disable Frame Tags IBPEHEAD Reset Camera Head IBPEINTEG Start BPE Events IBPELED Set LED IBPESFTYCONFIG Specify BPE Safing IBPESTARTCNTRDLD Start BPE Centroid Table Load IBPESTARTWNDWLD Start BPE Window Table Load IBPESTOPCNTRDLD Stop BPE Centroid Table Load IBPESTOPWNDWLD Stop BPE Window Table Load IBPETHRESHOLD Set BPE Threshold ICHANGELIMITS Change Limit Table Entry IDMMOVE Move Dichroic IDMSTOP Stop Dichroic Movement IDPUABORT Abort DPU IDPUMODE DPU Mode comm
198. table described in appendix B 13 Swift User Manual Swift UVOT 302 R03 C 16 P1 0 if detected when we are settled 1 if detected when we are settling P2 the current RA expressed and rounded up to the nearest minute of arc hex P3 the current DEC 100 degrees rounded up and expressed to the nearest minute of arc hex The ICU response is detailed in the Errors Action Table see appendix B 8 C 90 Reducing Requested Exp Time 4b hex This event message is issued when because of on board calculations the ICU has reduced the requested exposure for detector safety reasons P1 Current UVOT Mode P2 Requested exposure length in seconds and hex P3 Allowed exposure length in seconds and hex C 91 RTS Line Trace 77 hex This event message is issued as a diagnostic when enabled irt st on command It shows the current progress of RTS execution 1 Current RTS line number in hex starting from 1 P2 Current RTS in hex see RTS table appendix D 1 in the Message Codes appendix P3 Call depth zero top C 92 Running Recovery RTS ff hex This event message is issued when an RTS has been run by the ICU in an attempt to recover from an error indicated by the associated Major Anomaly error message which is often displayed immediately after this message RTS being run in hex see RTS table appendix D 1 in the Message Codes appendix P2 the associated error code see Err
199. tain the mirror separation In addition fine tuning of the latter separation may be required on orbit to maintain focus These active controls are performed using four instrument heaters Their functions are summarized as follows Swift User Manual Swift UVOT 302 R03 22 Heater Purpose Main Interface Heater Forward Heater HTR2 Metering Rod Heaters HTR3 Secondary Mirror Mount Heater HTR4 This is located close to the interface flange on the telescope tube and is intended to control the temperature at the interface bolts to 19 5 0 5 using a closed loop algorithm see section 2 5 4 3 It has a control thermistor Main located close to it and there are 3 monitoring thermistors Ref A Ref B and Ref C on the interface flange This is located at the forward of the telescope tube and is intended to control that area and hence the whole telescope tube to about the same temperature as the main interface heater the default setting are 19 5 1 5 using a closed loop algorithm see section 2 5 4 3 This should ensure that all of the telescope optical elements are sensibly isothermal It is controlled by one of two thermistors Forward 1 or Forward 2 mounted close to it These are a set of three parallel heaters one mounted on each of the metering rods These are used to extend the distance between the primary and secondary mirror by a small amount if necessary This is done using an open loop algorith
200. termine its actions The spacecraft supplies an Attitude Control System ACS message SISCATTITUDE at a frequency of 5 Hz This contains an identifier uniquely specifying the current observation It also supplies Boolean flags indicating whether the spacecraft has settled is within 10 arc minutes of its final position and whether we are currently inside the SAA It also includes a flag that if true signals that the spacecraft may be about to remove instrument power Positional information specifically the current right ascension and declination of the source and the satellite s latitude and longitude are supplied Timing information in the form of the current spacecraft clock setting is contained within the same record The spacecraft supplies a hardware driven Hz timing pulse referred to as the 1PPS Between these pulses a message SITIMETONE that supplies the spacecraft clock and UTC values at the next pulse is sent Telecommands are sent by the spacecraft to notify the instrument when a slew is about to commence SISLEWWARNIG or if a signalled slew has been abandoned SISLEWABORT Prior to slewing to the next source referred to here as the target the Figure of Merit Process FOM an internal process in the BAT sends out a FONEXTOBSINFO message detailing the next observation This includes an identifier uniquely specifying the next observation and a flag identifying it as an automated or planned target For an automated target
201. the time since the source was detected and whether this is the first visit to that source are also given The target right ascension declination and roll are supplied together with the anticipated maximum observing time on the source before the next interruption allowing for anticipated interruptions by the SAA For all types of observations it further supplies a value known as the UVOT mode that the ICU uses to select the sequence of exposures to run on the target The BAT supplies a BATBRBFLUXINFO message detailing burst brightness information If this indicates a bright source the ICU may modify its choice of exposure sequence see section 1 3 11 5 Finally the XRT may supply a refined position for a GRB using the XRTPOSITION message whilst the UVOT is performing the finding chart exposure This will impact on the area of detector that needs to be processed to ensure the inclusion of the source 1 3 6 Design Philosophy In order to achieve the flexibility required a design based primarily around three types of tables stored in EEPROM was chosen these tables have an associated Cyclic Redundancy Check value that is used to validate each table as it is loaded into random access memory RAM prior to use The design aim is that most if not all proposed changes to the behaviour of the system could be achieved by modifying one or more of these tables 1 3 7 EEPROM Located Tables There are three types of table images stored in
202. tive Area cm 20 Opt Grism 90 4 UV Grism 504 40 4 Effective Area cm 30 4 20 4 10 4 200 Wavelength nm Swift User Manual Swift UVOT 302 R03 20 1 2 3 2 Dichroic Mechanism The dichroic mechanism contains a mirror placed at 45 in the path of the incoming beam The purpose of the mechanism in the TM is to steer the reflected light beam from one of two redundant detector systems to the other It will be rotated from one position to the other by pulse counting The final step will drive the rotor to its stop where it will be held by a magnetic detent The dichroic mechanism is rotated 180 between the stops and by a 4 step per revolution motor geared at 14 5 1 Therefore the motor needs to be driven up to 29 steps from one position to the other One further step in each direction means that the rotor is driven hard onto its stop Thus the total number of steps required is 31 The step sequence has to be reversed to return As there is no harm in overdriving the system against this stop the motor is always driven the maximum number of steps required in the specified direction Thedrive frequency is 2 Hz A pulse train must always finish on a particular phase It is clear that this phase will be different at the two ends of the traverse As there are no sensors in the system the control mechanism is always open loop The following algorithm is used If we label the
203. tly a separate description is given for each type 2 5 4 3 Non Focussing These parameters specify a bang bang algorithm i e heaters should be off when the temperature is above a specified range and on when below a specified range Number Specifies which heater Values are 1 ZINTERFACE or 2 FORWARD OnTime Ignored should be set to zero CycleTime Ignored should be set to zero TMin Vnom Specifies the lower value of the allowed temperature in raw thermistor i e uncalibrated units TMax Vdrop Specifies the upper value of the allowed temperature in raw thermistor i e uncalibrated units NumThermistors Specifies how many thermistors are to be polled An average of those thermistor readings is then calculated and compared against the values given by TMin_VNom and TMax VDrop It can take the range 1 3 If its value is one then the thermistor number given by Therm will be used When the value is two then the average of the thermistors specified by Therml and Therm2 will be used etc Therm1 The thermistors to be polled The code numbers are as follows Therm2 Thermistor Description Therm3 0 BPE 1 Reference B 2 Reference C 3 Main 4 Forward 1 Forward 2 6 CCD 7 Reference A 2 5 4 4 Focussing These parameters state the nominal length of time the specified heater should be on within a fixed cycle time this is referred to as the duty cycle However the power developed is a function of potentially va
204. ttom plate and the cathode V cathode and the voltage across MCP1 mepi Converter 1 produces negative voltage so that with the use of resistive division with converter 2 it obtains zero volt output for V cathode on command Potential reversal is possible but limited approximately to less than 15 volts by diode protection Converter 3 is in series with converter 1 and 2 and produces the bias voltage across mcp23 and the anode gap voltage known as Vincp23 and V anode where V anode is produced by extension of the voltage multiplier chain used to create V s Swift User Manual Swift UVOT 302 R03 10 In order to prevent potential reversal of any intensifier plate the bias voltages must be applied sequentially this sequence being Vanode V mep23 Vmcpl then Vcathode The HVU hardware will prevent any controlled static potentials from reverse bias conditions even if commanded to do so Due to the way the HVU works there are conditions in which rapidly control signals could cause momentary reverse bias conditions Because of this it is necessary that software commanding for bias potentials be rise time limited It is recommended that any MCP rise time be limited to greater than 10 seconds from zero volts to maximum operating voltage and greater than 10 seconds from maximum operating voltage to zero volts Protection of over voltage on any MCP is also incorporated into the HVU hardware such that any command above maximum operating voltage
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206. up the High Voltages when we are in the Safe state and the Filter Wheel is not in a blocked position The parameters are as for HV Ramp Failed message see appendix C 68 C 64 FW Not Yet Datumed 6b hex This verification error message is issued when an attempt is made to move the filter wheel to an absolute rather than relative position before it has been previously datumed and thus has its current position established The APID and Function Code returned should be used in conjunction with the Command Table appendix D 2 in the Message Codes appendix to determine which command was rejected C 65 HV Above Below Requested 11 hex This error message is issued when an HV ramp is aborted because Swift User Manual Swift UVOT 302 R03 C 13 1 the target voltage is already above the current voltage when a ramp rate has been explicitly commanded as positive 2 the target voltage is already below the current voltage when a ramp rate has been explicitly commanded as negative The parameters are the same as for HV Ramp Failed see appendix C 68 C 66 HV Calibration Data Failure 14 hex This verification failure message is issued when an attempt to command the high voltages fails because the on board calibration data is not sensible This usually indicates human error in the compilation of that table The APID and Function Code returned should be used in conjunction with the Command Table appendix D 2 in the Message Codes appendix to deter
207. used by the ICU to lookup from EEPROM located tables a list of exposures to be performed during the snapshot For PT exposures it has a value in the range 9 to Ox7ffe If the value of UVOT Mode is greater than or equal to 0x1000 the exposure times supplied for those exposures are scaled to fit into the expected possible observing time during the snapshot This is obtained from the OBSERVE_SECONDS parameter in the FONEXTOBSINFO record It is intended that this type of exposure will be used for science exposures Note that it is assumed that the value of the OBSERVE_SECONDS parameter will take into account expected interruptions due to the SAA If the value of UVOT mode is less than 0x1000 then the exposure time remain unaltered It is intended that this type of exposure will be used for calibration and engineering exposures Having performed the above adjustments the ICU performs the first exposure in the list Upon completion of the exposure the UVOT resets itself by transitioning to the current PT state It then selects the next exposure configuration This process repeats until the next slew warning when it transitions to the Slew state or until the list of exposures is exhausted in which case it will transition to the Idle state 1 3 11 7 Safe Pointing Observation NOTE For all types of exposures the ICU maintains a running theoretical total of counts received so far at each catalogued star position in the field of view Should this number
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209. wift User Manual Swift UVOT 302 R03 C 2 indicates the procedure and the code location where the progress line was executed The precise values used are obtained by examining the code The ICU response is detailed in the Errors Action Table see appendix B 8 C 4 Already at Requested HV 15 hex This event message is issued when within the default tolerance the HV channel is already at the requested voltage The parameters the same as for the Ramp Failed message appendix 68 C 5 Angular Constraint Violation 54 hex This error message is issued when an angular constraint has been violated 1 Earth angular distance from pointing position in degrees and hex P2 Sun angular distance from pointing position in degrees and hex P3 Moon angular distance from pointing position in degrees and hex The ICU response is detailed in the Errors Action Table see appendix B 8 C 6 Automatic State 53 hex This event message is issued when an event on the spacecraft has resulted in the ICU making an autonomous decision to transition to another state 1 RTS number in hex to be executed to perform the state transit see RTS codes in the message code appendix D 1 P2 Current State see state codes appendix D 8 in the Message Codes appendix P3 AA hex C 7 Data EEPROM 93 hex This error message is issued when bad data i e nonsensical has been detected in an EEPROM section This is
210. with that of the main catalogue source instead Each entry is stored as three words Byte Contents 1 RA division the source is in see Catalogue Star in error message appendix Encoded version of its declination band see Catalogue Star in error message appendix RA offset from the origin of its sky area arc minutes Declination offset arc minutes Magnitude code see message table appendix D 5 for codes used Colour index code see message table appendix D 6 for codes used It also contains an end of list marker consisting of three words all of them OxFFFF This will be positioned at the end of the relevant entries in the addendum If there are no entries it will be at the beginning of the addendum All allotted space after the end of list marker is zero filled The last word of the addendum is the CRC value Swift User Manual Swift UVOT 302 R03 B 6 3 Command Database This database is derived from the ITOS command database It describes each command in sufficient detail for the RTS system to construct a command on the fly for internal and occasionally external submission Each command is described by a variable length block ending with a CRC The code used to represent a call to a particular command within an RTS script is the offset of that command with this database This enables the code that executes an RTS to immediately locate the approp
211. x This error message is issued when the start address from which to dump was invalid Memory address high word P2 Memory address low word 0 C 80 Illegal State 0a hex This verification failure message is issued when the state parameter in the command with the indicated APID and Function Code is outside the expected range see the Command Table appendix D 2 in the Message Codes appendix for a list of the APIDs and Functions Codes and the state table appendix D 8 for a list of valid states C 81 Impossible State Transition 43 hex This error message is issued when a state change command has been issued and the ICU is unable to find such a transition in its on board table described in appendix B 12 This usually indicates a corruption of the table that has survived a CRC check The probability is therefore that human error occurred when compiling the table P1 Current State see state table appendix D 8 the Message Codes appendix P2 Requested State see state table appendix D 8 in the Message Codes appendix 0 The ICU response is detailed in the Errors Action Table see appendix 8 C 82 Incorrect Checksum 01 hex This verification error message is issued when a command with the indicated APID and Function Code is received with an incorrect checksum see the Command Table appendix D 2 in the Message Codes appendix for a list of the APIDs and Functions Codes 0 P2 0
212. x DCS Exiting RTS 83 hex DCS Insufficient Priority 76 hex DCS Invalid Command Token 73 hex DCS Invalid Exec Token 86 hex DCS Invalid Poke Offset 87 hex DCS No Such RTS 71 hex DCS RTS Already Running 80 hex DCS Stack Exceeded 72 hex B 19 B 20 B 21 C 1 C 1 1 1 2 2 2 2 3 3 3 C 3 C 3 C 4 C 4 C 4 C 6 C 6 C 6 C 6 C 6 C 7 C 7 C 7 C 7 C 7 8 8 8 8 8 8 8 Swift User Manual Swift UVOT 302 R03 C 33 34 35 36 37 38 39 C 40 C 41 C 42 C 43 C 44 C 45 C 46 C 47 C 48 C 49 C 50 C 51 C 52 C 53 C 54 C55 C 56 57 58 59 60 61 62 63 64 65 C 66 C 67 68 DCS Starting RTS 79 hex DCS State Table Match Fail 7a hex DCS Too Few RTS Arguments 85 hex Debug Output hex DM at Requested Position 68 hex DM Lost Position 6a hex DPU Ack Nack No error event code displayed DPU Bad Bounds 36 hex DPU BootCmplt No error event code displayed DPU ChnBndClc No error event code displayed DPU Inconsistent APID ID 34 hex DPU Incorrect ACK 32 hex DPU Invalid APID or ID 35 hex DPU Mode Cmpl No error event code displayed DPU Mode Rdy No error event code displayed DPU NAK 30 hex DPU Time out 31 hex DPU Unexpected ACK NAK 33 hex Upld Strt No error event code displayed DPU Upld End No error event code displayed EEPROM Code Compare Error a7 hex EEPR
213. y Orbit Turn on UVOT 02 Emergency Power Off UVOT 03 Emergency Safing UVOT 04 Power Off and On UVOT 05 Recovery from Safehold UVOT 06 Safing and Recovery UVOT 07 Recovery from Safety Circuit Trip UVOT 08 Observing Proc List UVOT 09 Utility Proc List UVOT 10 TDRSS HK UVOT 11 Alert Message Response UVOT 12 Lost Filter Wheel Position UVOT 13 ICU Code RTS Upload UVOT 14 DPU Upload Code Image UVOT 15 DPU DCI Lockup Recovery 39 39 40 40 40 40 41 42 43 43 43 43 44 44 44 45 45 Swift User Manual Swift UVOT 302 R03 2 3 16 UVOT 16 Recovery from Watchdog Trip 45 2 3 17 UVOT 17 DPU Upload Table 45 2 3 18 UVOT 18 DPU Upload Install Patch 45 2 4 Limit Violation Response Matrix 46 2 4 1 ICU 47 2 4 2 DPU 55 2 4 3 Spacecraft 57 2 5 Special Operations 58 2 5 1 How to Override Table Values in Ram 58 2 5 2 Dumping or CRC Checking Memory when Observing 58 2 5 3 Loading or Dumping Memory at the Same Time 58 2 5 4 Heater Control Parameters Use of IHTRPARAMS 58 2 5 5 Direct Control and Monitoring of ICB Ports 60 2 5 6 ICU Basic Special Considerations 63 2 6 Guide to ICU HK Page 64 3 Fault Trees 70 3 1 Safety Circuit Trip 70 3 2 TM gets turned off 71 3 3 UVOT gets turned off 71 3 4 ICU has an error not covered above 72 3 5 ICU reboots and ends up in BASIC State 72 3 6 ICU has a limit violation 73 Appendix A Detailed Description of EEPROM A Located Tables 1 1 Overview 1 A 2 Heater Contro
214. ystem enable and alert enable bits Read the alert flag bit at regular intervals Swift UVOT 302 R03 wait for new pixel pixel gt threshold reset pixel count reset frame count pixel count gt hreshold onsecutive frames gt threshold Safety Circuit Flow Diagram alert lower cathode voltage cathode control to power down the other HV rails and reset the alert A 1 1 2 2 5 4 Known problems See MSSL NCR 121 ISFTYSYSEN occasionally goes to 0 All the early safety circuit trips were slewing over bright mag 2 4 blue like O and B stars except for trip in a grism exposure with a slowly increasing background caused by the Earth approaching 2 trips observing and preparing to observe the SMC which has many bright stars which looks brighter to the safety circuit because of overlap 2 trips in the B filter for no apparent reason If the alert flag is set the cathode has been set to automatically by the safety circuit The ICU will set the Swift User Manual Swift UVOT 302 R03 14 1 2 2 6 Detector Processing Electronics 1 2 2 6 1 General The principal features of the detector processing electronics are Generation of the Detector Head clock sequences to operate the CCD in a frame transfer mode Specification of the area windows of the CCD to be read out Event Detection Event Centroiding Engineering Data Construction and transmission of data to the DPU

SWIFT UVOT USERS GUIDE - Mullard Space Science Laboratory

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