ĐỒNG HỒ SỐ AGILENT 34401A 6

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SV: Nguyn Cng Linh 09DT2

NG H S AGILENT 34401A 6 DIGITChng 7:

HNG DN CCH O

ng h o s Aglilent 34401A c chnh xc cao. t c chnh xc cao nht cn phi loi b cc li thng gp phi trong cc php o. Chng ny gii thiu v cc li thng gp khi o v cch khc phc. 1. Sai s do nhit EMF (Thermal EMF Errors): in p nhit in l nguyn nhn gy sai s ph bin nht trong php o in p dc mc thp. Mi mi ni kim loi to thnh mt cp nhit ngu (thermocouple), to ra mt in p t l vi nhit tip gip. Cn phi gim thiu s hnh thnh cc cp nhit in ti cc tip gip v s thay i nhit cc php o in p mc thp. Tip gip tt nht l tip gip gia ng ng (copper to copper). Bng di y cho bit in p nhit in gia cc tip gip khc nhau:

u que o ca ng h Agilent lm bng hp kim ng. 2. Sai s do qu ti (Loading Errors): (trong php o in p dc) Sai s do qu ti gp phi trong qu trnh o thng do tr khng ca thit b c kim tra (device-under-test DUT) ln ng k so vi tr khng vo ca ng h o. Hnh di y ch r nguyn nhn ca li ny:

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gim thiu sai s ny v tc ng ca can nhiu (noise pickup), tr khng vo ca ng h o cn ln hn 10 G i vi cc php o mc 100 mVdc, 1 Vdc, 10 Vdc v khong 10 M i vi cc php o mc 100 Vdc v 1000 Vdc. 3. Sai s dng r (Leakage Current Errors): in dung ng vo ca ng h o s c np nh dng phn cc ng vo khi u que o b h mch (nu tr khng vo l 10 G). Dng phn cc ng vo khong 30 pA nhit t 0 30oC. nhit trn 30oC dng phn cc s tng gp i khi nhit tng ln 8oC. Dng ny to ra mt in p offset nh ph thuc vo tr khng ngun ca thit b c kim tra. in p ny s ng k nu tr khng ngun > 100 K hoc ng h o lm vic nhit ln hn nhiu so vi 30oC.

4. Trit in p nhiu ngun (Rejecting Power - Line Noise Voltages): Mt c tnh mong mun ca vic ly mu chuyn i tng t sang s A/D l kh nng loi b cc tn hiu tp nhiu. Vic ly mu s loi b c nhiu ngun i vi tn hiu dc ng vo, gi l trit nhiu ch trung bnh NMR (Normal Mode Rejection). ng h o s ly gi tr trung bnh ca tn hiu vo bng cch tch phn trong mt thi gian c nh. Nu thi gian ly mu l s nguyn ln chu k ng ti (power line cycles - PLCs) th tp nhiu (v cc hi ca n) s xp x bng 0.

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ng h Agilent c 3 b chuyn i A/D tch phn theo thi gian trit nhiu ngun. Khi cp ngun cho ng h o, n s o tn s ca ngun (50 60 Hz) v xc nh thi gian ly mu. tng phn gii v loi b nhiu th thi gian ly mu cng ln cng tt. Tham kho bng sau:

5. Common Mode Rejection (CMR): ng h o l tng c xem nh c lp hon ton so vi mch tham chiu t (earth-referenced circuits). Tuy nhin, thc t c mt tr khng vo gia u que o m (LO) ca ng h v t gy ra sai s khi thc hin php o in p thp so vi t.

6. Nhiu gy bi t trng vng (Noise Caused by Magnetic Loops): Khi thc hin php o gn t trng, cn trnh gy ra in p nhiu trong cc kt ni ca php o, c bit trong trng hp gn dy dn mang dng in ln. S dng cp

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cc xon gim can nhiu vng kn v cc cc o cng gn nhau cng tt. Cc cc o b lng hoc rung cng gy ra in p nhiu. Phi chc chn l cc cc o c c nh khi o gn t trng. S dng vt chn hoc cch ly gim tc ng ca t trng. 7. Nhiu gy bi vng khp mch qua t (Noise Caused by Ground Loops): Khi o in p trong mch, c ng h v thit b c o u ni t s gy nn 1 vng t ground loop. Bt k mt s sai khc in p nh gia 2 im t tham chiu Vground cng s gy ra mt dng in nh chy qua gia 2 cc ca ng h o gy ra in p nhiu offset s c cng thm vo php o in p. gim gy ra cc vng t, khng c ni cc cc ng vo vi t. Nu phi ni t cc o ca ng h, phi chc chn rng ng h v thit b c o phi cng chung 1 im t gip gim hoc loi b c s sai khc in p gia 2 im t. Nu c th nn ni chung ng h o v thit b c o cng mt in.

8. Php o in tr: ng h o Agilent 34401A c th o in tr bng 2 phng php: o 2 dy v o 4 dy. c 2 phng php, dng o u chy t que o dng (HI) ca ng h qua in tr cn o. i vi phng php o 2 dy, in p ri trn in tr cn o c cm ng

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(sensed) bn trong ng h, do in tr ca u que o cng c tnh vo. i vi phng php o 4 dy, c thm 2 dy cm ng (sense) ring bit. Do khng c dng chy qua u que cm ng nn khng gy ra sai s khi o. Cc sai s trnh by phn trc i vi php o in p dc cng c p dng cho php o in tr. Cc li khc ca php o in tr s c trnh by phn sau. 9. Phng php o in tr bng 4 dy (4-Wire Ohms Measurements): Phng php ny cho chnh xc cao nht khi o cc in tr nh. in tr u que o v in tr lin lc s t ng gim khi dng phng php ny. Phng php ny c s dng trong cc ng dng o t ng i vi trng hp dy cp qu di, nhiu kt ni, hoc tn ti cc chuyn mch gia ng h o v thit b cn o. Kt ni cho phng php o ny nh hnh di:

10. Loi b sai s in tr que o: trit sai s offset lin quand dn in tr que o trong phng php o 2 dy, ta thc hin cc bc sau: 1. Chp 2 u que o li. ng h s hin th gi tr in tr ca u que o. 2. Nhn nt NULL trn ng h. ng h s hin th 0 khi chp 2 u que o. 11. nh hng do cng sut tiu tn (Power Dissipation Effects): Khi o in tr hoc cc cu kin c tnh tr vi h s nhit ln th ng h o s tiu tn mt phn cng sut trn vt cn o. Nu cng sut tiu tn l mt vn , cn chn

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mc o cao hn gim thiu sai s n mc chp nhn c. Xem mt vi v d trong bng di y:

12. nh hng do thi gian x l php o (Settling Time Effects): ng h s Agilent 34401A c kh t ng chn thi gian tr khi x l php o. Thi gian tr ny thch hp cho cc php o i vi cc thit b v cp ni c in dung nh hn 200 pF. iu ny c bit quan trng nu thc hin php o in tr trn 100 K. Vic thit lp c th kh lu do nh hng ca thi hng RC. S dng cc in tr c chnh xc cao v cc t c in dung ln (1000 pF to 0.1 F) mc song song lc cc dng nhiu trong mch. Cc in dung khng l tng trong cc cp v cc thit b khc c thi gian x l lu hn mong mun do thi hng RC ph thuc vo hiu ng hp th in mi. 13. Sai s khi o in tr cao (Errors in High Resistance Measurements): Khi ta o in tr c gi tr ln, s c sai s ng k do in tr cch ly v hun cu b mt (surface cleanliness). Cn c bin php gi c sch ca h thng tr khng cao. u que o v cc vt c nh thng b r do s hp th hi m trong vt liu cch ly v lp mng b mt tp (dirty surface films). Nilon v PVC cch in km hn (109) so vi PTFE Teflon (1013). Dng r t vt cch in dng nilon hoc PVC s d dng to ra sai s 0.1% khi o in tr khong 1 M trong iu kin m t. 14. Sai s khi o dng mt chiu (DC Current Measurement Errors): Khi mc ng h ni tip vi mch cn o o dng, s to ra mt sai s gy ra bi in p gnh (burden voltage) ni tip ca ng h - l in tr sinh ra bi in tr dy ni v in tr song song nh hnh.

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VS: Ngun in p RS: Ni tr ca thit b cn o VB: in p gnh ca ng h o R: in tr song song ca ng h

15. o gi tr hiu dng thc ca tn hiu xoay chiu (True RMS AC Measurements): Cc ng h p ng gi tr hiu dng thc, nh ng h Agilent 34401A, o gi tr xoay chiu ca in p t vo. Khng ging nh php o p ng gi tr trung bnh, php o gi tr hiu dng thc thng xc nh cng sut tiu tn trn mt in tr. Cng sut t l vi bnh phng in p hiu dng o c, khng ph thuc vo dng sng. Mt ng h p ng gi tr trung bnh ac c hiu chnh c tng t mt ng h o tr hiu dng ch dnh cho tn hiu vo l sng sin. i vi cc dng sng khc, o gi tr p ng trung bnh s cho sai s nh hnh di:

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Chc nng o dng v in p xoay chiu o gi tr hiu dng thc c ghp ac, ngc vi gi tr hiu dng ac+dc nh trn. Ch c thnh phn xoay chiu c o, cn thnh phn 1 chiu b b qua. i vi sng sin, sng tam gic v sng vung, thnh phn ac v ac+dc bng nhau v dng sng khng cha thnh phn dch 1 chiu (dc offset). Cc dng sng khng i xng, v d mt dy xung, th thnh phn dc s b b qua khi dng phng php o gi tr hiu dng ghp u vo ac. Php o gi tr hiu dng ghp u vo ac o gi tr mong mun ca tn hiu xoay chiu nh trong khi tn ti thnh phn dch 1 chiu ln. V d nh o in p gn xoay chiu ca ngun cung cp 1 chiu. Tuy nhin, trong trng hp mun bit gi tr hiu dng ac+dc ta c th xc nh gi tr ny bng cch kt hp kt qu o c t php o ac v dc theo cng thc di y. Nn s dng thi gian ly mu (tch phn) t nht bng 10 ln chu k ng ti (powerline cycles) ch 6 digits loi b thnh phn ac tt nht.

16. Sai s h s nh (u vo khng phi dng sin): Crest Factor Errors (nonsinusoidal inputs) Mt quan nim sai lm ph bin l V ng h o AC cho gi tr hiu dng thc nn cc thng s chnh xc ca sng sin cng c p dng cho tt c cc dng sng. Thc t, hnh dng ca tn hiu vo c th nh hng ng k n chnh xc ca php o. Mt cch ph bin m t dng tn hiu l h s nh (crest factor). H s nh l t s ca gi tr nh vi gi tr hiu dng ca dng sng. V d i vi dy xung, h s nh l xp x bngT nh bng cho chng t

trc. Mt cch tng qut, h s nh cng ln th nng lng cha trong hi tn bc cao cng cao. Tt c ng h u c sai s php o ph thuc vo h s nh. Sai s h s nh ca ng h Agilent 34401A s c trnh by trong chng tip. Ch rng sai s h s nh khng p dng cho tn hiu vo di 100 Hz khi s dng b lc AC chm. C th c lng sai s php o do h s nh tn hiu nh sau: Tng sai s = sai s (sin) + sai s (h s nh) + sai s (bng thng) Sai s (sin) Sai s (h s nh) Sai s (bng thng) : sai s ca sng sin (trnh by trong chng tip theo) : trnh by chng tip theo : c lng sai s bng thng nh sau

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V d: Tnh sai s php o xp x cho mt dy xung vo vi h s nh l 3 v tn s c bn l 20kHz. i vi v d ny ta cho rng thng s chnh xc 90 ngy ca ng h l (0.05% + 0.03%). Tng sai s = 0.08% + 0.15% + 1.4% = 1.6% 17. Sai s ph ti (in p xoay chiu): Loading Errors (ac volts) Trong chc nng o in p xoay chiu, u vo ca ng h Agilent 34401A c mt in tr 1M song song vi mt t c in dung 100pF. Cp ni s dng ni tn hiu ti ng h cng thm vo in dung v ph ti. Bng di y ch ra in tr u vo xp x ti cc tn s khc nhau ca ng h.

Vi tn s thp

Sai s tng thm vi tn s cao

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18. Php o di mc y thang (Measurements Below Full Scale): C th thc hin php o ac chnh xc nht khi ng h ch ti mc y thang ca di chn o. T ng chn thang o xy ra ti 10% v 120% ca mc y thang cho php o mt vi tn hiu vo ti mc y thang trn mt thang o v 10% ca mc y thang trn thang o cao hn tip theo. chnh xc s sai khc ng k cho 2 trng hp . c chnh xc cao nht, nn chn thang o bng tay ly thang thp nht c th cho php o. 19. Sai s do nhit in p cao (High Voltage Self Heating Errors): Nu t in p vo ln hn 300 Vrms, s nng ln do nhit s xy ra trong thnh phn iu ha tn hiu (signal conditioning) bn trong ng h. Cc sai s c trong cc thng s k thut ng h. S thay i nhit bn trong ng h do s t nng ln do nhit c th gy thm sai s trn cc di in p xoay chiu khc, sai s thm vo s nh hn 0.02% v s mt i trong vi pht. 20. H s nhit v sai s qu ti (Temperature Coefficient and Overload Errors): ng h Agilent 34401A s dng k thut o xoay chiu c th o v loi b in p lch bn trong khi chn mt chc nng hoc thang o khc. Nu ng h cng mt thang o trong mt khong thi gian lu, v nhit xung quanh thay i ng k (hoc nu ng h khng c lm lm nng hon ton), th p lch bn trong c th thay i. H s nhit ny thng l 0.002% ca thang o/oC v t ng mt i khi thay i thang o hay chc nng. Khi iu chnh thang o bng tay sang mt thang o khc trong iu kin qu ti, in p lch bn trong c th gim. Thng th, sai s thm vo 0.01% ca thang o c th xut hin, sai s thm vo ny s t ng mt i khi ta lm mt nh hng qu ti v thay i chc nng hoc thang o. 21. Sai s php o mc thp (Low-Level Measurement Errors): Khi o in p xoay chiu nh hn 100mV th nhng php o d b sai s t ngun nhiu ngoi. Mt u o trn s hot ng nh mt anten v ng h thc hin chc nng ng s o tn hiu nhn c. Ton b ng o, bao gm c ng ti, hot ng nh mt anten vng. Dng lan truyn trong vng s to sai s in p trn hai u bt k tr khng no ni tip vi ng vo ca ng h. Do ta nn t in p xoay chiu mc thp vo ng h o thng qua mt cp c bc v. Nn ni lp v ti chn u vo thp (LO). m bo ng h v ngun xoay chiu c kt ni ti cng mt cm in nu c th. Nn gim thiu nhng vng c vng t ci m khng th trnh khi. Mt ngun tr khng cao th d b can nhiu hn ngun tr khng thp. C th gim tr khng tn s cao ca mt ngun bng cch t mt t song song vi u vo ca ng h, c th phi dng thc nghim xc nh gi tr t ng cho tng ng dng.

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Hu ht ngun nhiu t bn ngoi th khng tng quan vi tn hiu vo, sai s c xc nh nh sau :

Nhiu tng quan, t xy ra, gy nhng sai khc c bit. Nhiu tng quan lun thm nhp trc tip vo tn hiu vo. o mt mc tn hiu thp c cng tn s vi ng ti l trng hp ph bin hng v sai s ny. 22. Sai s ng pha (Common Mode Errors): Nhng sai s sinh ra khi chn vo thp (LO) ca ng h c truyn vi mt in p xoay chiu so vi t. V tr ph bin nht ni in p ng pha khng cn thit c to l khi ng ra ca mt b nh c xoay chiu c ni ti pha sau ng h (multimeter backwards). Mt cch l tng, mt ng h c ging nhau bt chp ngun c ni nh th no. C nh hng ngun v ng h c th lm gim trng hp l tng ny. Do in dung gia chn thp (LO) ng vo v t (xp x 200pF i vi ng h Agilent 34401A), ngun s tri qua nhng ti khc nhau ph thuc vo cch thc tn hiu vo c t vo. Bin ca sai s ph thuc vo p ng ca ngun ti ti ph ti. S mch o ca ng h p ng p ng khc nhau trong hp vo sau do s hi khc nhau trong in dung k sinh. Sai s ng h l ln nht i vi in p cao, tn s cao ng vo. in hnh, ng h s cho khong 0.06% sai s i vi 100V, 100kHz ng vo o. C th s dng k thut ni t biu din vn ng pha mt chiu lm gim thiu in p ng pha xoay chiu. 23. Sai s php o dng xoay chiu (AC Current Measurement Errors): Sai s in p gnh, tng ng vi dng mt chiu, cng c p dng trong php o dng xoay chiu. Tuy nhin, in p gnh cho dng xoay chiu th ln hn do cm khng ni tip ca ng h o v cc kt ni ca php o. in p gnh tng khi tn s u vo tng. Mt vi mch c th dao ng khi thc hin cc php o dng do cm khng ni tip ca ng h o v cc kt ni ca php o. 24. Sai s php o chu k v tn s (Frequency and Period Measurement Errors): ng h s dng k thut m thun nghch (reciprocal counting technique) o chu k v tn s. Phng php ny to ra hng s phn gii php o i vi mi tn s. Phn php o in p xoay chiu ca ng h thc hin vic iu phi tn hiu vo. Tt c cc b m tn s u d b sai s khi o tn hiu p thp, tn s thp. nh hng ca nhiu trong v can nhiu ngoi ti hn khi o tn hiu chm. Sai s t l nghch vi tn s. Sai s php o cng s xy ra nu o tn s (hoc chu k) ca mt u vo k tip mt in p lch DC bin i. Phi cho t in cm ng u vo mt chiu ca ng h t full trc khi thc hin php o tn s.

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25. Thc hin php in tr v DC tc cao (Making High-Speed DC and Resistance Measurements): ng h kt hp t ng reset v 0 khi o (autozero) trit thermal EMF trong v sai s dng phn cc. Mi php o thc s bao gm mt php o ca chn u vo theo bi mt php o in p lch trong. Sai s in p lch trong c tr t u vo ci thin chnh xc. Vic b cho in p lch ny thay i do nhit . t tc c ti a, tt chc nng autozero. N s tng hn gp i tc c i vi chc nng o p mt chiu, in tr, v dng mt chiu. Autozero khng tng thch vi chc nng o khc. 26. Thc hin php o xoay chiu tc cao (Making High-Speed AC Measurements): Chc nng o p v dng xoay chiu ca ng h b sung 3 b lc tn s thp khc nhau. Nhng b lc nhm nh i chnh xc tn s thp t tc c nhanh hn. B lc nhanh t khong 0.1s, v c ch cho tn s trn 200Hz. B lc trung bnh t khong 1s, v c ch cho tn s trn 20Hz. B lc chm t khong 7s, v c ch cho tn s 3Hz. C th thc hin php o xoay chiu ti tc ln n 50 s ghi trn ng h trn mt giy. S dng iu chnh thang o bng tay loi b tr t ng chnh thang. Bng cch t tr kch khi c lp trnh bng 0, mi b lc s cho php n 50 s ghi trn ng h trn mt giy. Tuy nhin, php o c th khng chnh xc v b lc khng c t hon ton. Trong nhng ng dng m mc mu bin i rng, b lc trung bnh s t ti 1 s ghi trn ng h trn mt giy, v b lc nhanh s t ti 10 s ghi trn ng h trn mt giy. Nu mc mu l ging nhau, thi gian t t c yu cu cho mi con s mi. Di iu kin c bit ny, b lc trung bnh s cung cp kt qu vi chnh xc gim ti 5 s ghi trn ng h trn mt giy, v b lc nhanh s cung cp kt qu vi chnh xc gim ti 50 s ghi trn ng h trn mt giy. Thi gian t thm c th c yu cu khi mc dc bin i t mu ny ti mu kia. Mch dc blocking ca ng h t thi gian gi nguyn 0.2s. Vic t thi gian ny ch nh hng chnh xc php o khi mc lch dc bin i t mu ny ti mu kia. Nu tc php o ti a c mong mun trong h thng qut, c th thm mt mch dc blocking ngoi vo cc knh o vi in p dc ng k. Mch ny c th n gin gm in tr v t.

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Chng 5: CC THNG BO LI Thng bo Li Cc li c ly ra theo nguyn tc first-in-first-out (FIFO).Li u tin c thng bo l li u tin c lu tr. Khi bn c tt c cc li, thng bo li tt. My o pht ra ting bp mi khi c li. Nu hn 20 li xy ra, cc li cui cng c lu tr trong hng i (cc li gn y nht) c thay th bng -350, "Qu nhiu li". Khng c li c lu tr cho n khi bn loi b cc li t hng i. Nu khng c li xy ra khi bn c dng li, my o p ng vi +0, "Khng c li". Hng i li c xa khi ngun c ngt hoc sau mt lnh CLS * (trng thi xa) c thc hin. Lnh*RST (reset) khng xa hang i li. Hot ng ca bng iu khin trc: 3: ERROR (SYS MENU) Nu thng bo li c bt, bm shift + > (Recall Menu) c cc li c lu tr trong hng i. Cc li c lit k theo chiu ngang trn mc "tham s". Tt c cc li c xa khi bn i n mc "tham s" v sau tt menu. Hot ng giao tip t xa : SYSTem:ERRor? c mt li t hng i li Li c nh dng sau (chui li c th cha ln n 80 k t): -113, "Khng xc nh tiu " Li u tin trong hng i m li Li thc thi -101 K t khng hp l Mt k t khng hp l c tm thy trong chui lnh. Bn c th chn vo mt k t nh #, $,% trong tiu lnh hoc trong phm vi tham s. V d: CONF: VOLT # DC -102 Li c php

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C php khng hp l c tm thy trong chui lnh. Bn c th a vo mt khong trng trc hoc sau du hai chm trong tiu lnh, hoc trc mt du phy. V d: SAMP: COUN, 1 -103 Phn cch khng hp l Mt du phn cch khng hp l c tm thy trong chui lnh. Bn c th c s dng mt du phy thay v mt du hai chm, du chm phy, hoc khong trng - hoc bn c th s dng mt khong trng thay v mt du phy. V d: TRIG: COUN, 1 hoc CONF: 1000 0,1 FREQ -104 Li kiu d liu Cc kiu tham s sai c tm thy trong chui lnh V d: Disp: TEXT 5,0 -105 GET khng c php Kch khi thc thi theo nhm (GET) khng c php bn trong mt chui lnh. -108 Tham s khng c php Cc thng s khc nhn c hn d kin cho cc lnh.Bn c th nhp vo mt tham s ph, hoc bn thm vo mt tham s vo mt lnh m n khng c chp nhn. V d: READ? 10 -109 Thiu tham s t tham s nhn c hn d kin cho cc lnh. Bn b qua mt hoc nhiu tham s c yu cu cho vic ny. V d: SAMP:COUN -112 Chng trnh ghi nh qu di Mt tiu lnh nhn c trong c nhiu hn ti a 12 k t cho php. V d: CONFIGURATION: VOLT: DC -113 Khng xc nh tiu

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Mt lnh nhn c khng hp l vi my o a nng. Ta c th sai chnh t ca lnh hoc n c th l mt lnh khng hp l. Nu bn ang s dng dng ngn ca lnh, hy nh rng n c th cha bn ch ci. V d: TRIGG: COUN 3 -121 K t s khng hp l Mt k t s khng hp l c tm thy trong gi tr ca tham s. V d: STAT: QUES: ENAB #B01010102 -123 S trn Mt s tham s c tm thy c s m ln trn 32.000. V d: TRIG: COUN 1E34000 -124 Qu nhiu ch s Mt s tham s c tm thy cha hn 255 ch s, khng bao gm s khng hng u. -131 Hu t khng hp l Hu t A c quy nh khng chnh xc cho mt tham s . Qu v c th sai chnh t cc hu t. V d: TRIG: DEL 0,5 SECS -138 Hu t khng c php Hu t A c nhn sau mt s tham s m khng chp nhn hu t . V d: SAMP: COUN 1 SEC (SEC khng phi l mt hu t hp l). -148 Kiu d liu khng c php Mt tham s ri rc c nhn nhng mt chui k t hoc s tham s thiu. Kim tra danh sch cc tham s xc minh rng bn s dng mt loi tham s hp l. V d: DISP: TEXT ON -151 Chui d liu khng hp l Mt chui k t khng hp l c nhn. Kim tra xem nu bn c km theo cc chui k t trong du nhy n hoc kp v chui cha k t ASCII hp l. V d: DISP: TEXT ON (Du nhy cui b thiu). -158

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Chui d liu khng c php Mt chui k t c nhn nhng khng c cho php trong cu lnh. Kim tra danh sch cc tham s xc minh rng bn s dng mt kiu tham s hp l. V d: CALC: STAT ON ' -160 n -168 Khi d liu li My o a nng khng chp nhn d liu khi. -170 n -178 Biu hin li My o a nng khng chp nhn biu thc ton hc. -211 Kch khi b b qua GET hoc TRG * nhn c nhng kch khi b b qua. Hy chc chn rng my o trong trng thi "ch i-cho-kch hot" trng thi trc khi kch khi, v chc chn rng ngun kch khi c chn chnh xc. -213 Khi to b b qua Mt lnh khi to c tip nhn nhng khng th c thc hin bi v mt php o c tin hnh. -214 Kch khi tr tr Kch khi tr tr xy ra khi ngun kch hot l BUS v mt lnh READ? c nhn. Ci t xung t Li ny c th c to ra trong mt trong cc tnh hung sau y: Bn gi lnh CONFIGURE hay lnh MEASURE vi phn gii c nh. V d: CONF: VOLT: DC DEF, 0,1 Bn bt ch tnh ton (CALC: STAT ON) v sau thay i n hot ng khng hp l vi chc nng o lng hin ti. V d, o dB khng c cho php vi 2 dy ohms. Trng thi tnh ton c tt nh l mt kt qu ca tnh trng ny. -222 D liu ra khi phm vi Mt s tham s gi tr bn ngoi phm vi hp l cho cc lnh. V d: TRIG: COUN -3

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-223 Qu nhiu d liu Mt chui k t c nhn nhng khng c th c thc hin bi v cc chui chiu di hn 12 k t. Li ny c th c to ra bi lnh CALibration:STRing and DISPlay:TEXT -224 Gi tr tham s khng hp l Mt thng s ri rc c nhn khng phi l mt s la chn hp l cho lnh. Bn c th la chn tham s khng hp l. V d: CALC:FUNC SCALE ( SCALE l mt s la chn khng hp l). -230 C d liu Mt lnh FETCH c nhn nhng b nh c trong trng. c ly ra c th l khng hp l. -330 T kim tra li Xy ra khi giao tip t xa(lnh * TST ). Ngoi li ny ra, nhng li t kim tra ring cng c bo co. -350 Qu nhiu li Hng i li y v c hn 20 li xy ra. Khng c them li c lu tr cho n khi bn loi b cc li t hng i. Hng i li c xa khi ngun c tt, hoc sau mt lnh CLS * (tr ng thi xa)c thc hin. -410 Truy vn b gin on Mt lnh c nhn v gi d liu vo b m u ra, nhng b m u ra cha d liu t mt lnh trc (d liu trc khng b ghi ). Cc b m u ra c xa khi ngun c tt, hoc sau khi mt lnh * RST (reset) c thc hin. -420 Truy vn cha chm dt My o a nng c gii quyt ni chuyn (v d, gi d liu qua giao tip), nhng mt lnh khng c nhn gi d liu ti m u ra. V d, bn c th thc hin lnh CONFigure (m khng to ra d liu) v sau thm mt lnh ENTER c d liu t giao tip t xa. -430 Truy vn b tc

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Mt lnh nhn c to ra qu nhiu d liu ph hp vi b m ra v b m u vo cng y. Lnh thc thi tip tc nhng tt c cc d liu b mt. -440 Truy vn cha chm dt sau phn hi khng xc nh L nh * IDN phi c lnh truy vn cui cng trong mt chui lnh. V d: * IDN: Syst: Vers? 501 Li khung UART cch li 502 Li vt qu UART cch li 511 Li khung RS-232 512 Li trn RS-232 513 Li chn l RS-232 514 Lnh ch c cho php vi RS-232 C ba lnh ch c php vi RS-232 SYSTem:LOCal, SYSTem:REMote , v SYSTem:RWLock . 521 Trn b m vo 522 Trn b m ra 531 Khng b nh Khng c b nh lu tr s yu cu ca vic c trong b nh trong bng cch s dng lnh INITiate. m mu (SAMle: COUNT) v m kch khi (TRIGger: COUNT) khng c vt qu 512 yu cu c. 532 Khng th t c phn gii yu cu My o a nng khng th t c phn gii o lng c yu cu. Bn phi quy nh mt phn gii khng hp l trong lnh CONFigure hoc MEASure. 540 Khng th s dng qu ti nh ton t ton hc

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Vn nng k khng th lu tr mt c qu ti (9.90000000E 37) cc ti liu tham kho ton hc cho cc php o 0 hoc dB. Trng thi tnh ton tt nh l mt kt qu ca tnh trng ny. 550 Lnh khng c php a phng Vn nng k nhn c mt lnh READ hoc MEASure? trong khi ch a phng. Trong khi RS-232 hot ng, bn nn lun lun thc hin lnh SYSTem:REMote trc khi gi cc lnh khc ti b giao tip. T kim tra li Cc li sau y cho thy nhng li c th xy ra trong qu trnh t kim tra. 601 Mt trc khng p ng 602 RAM c / vit khng thnh cng 603 ng b A/D b mc kt 604 Mt hi t dc A/ D khng thnh cng 605 Khng th hiu chnh h s suy gim 606 H s suy gim vt khi phm vi cho php 607 Suy gim qu n nhiu 608 Cu hnh tun t i chiu khng thnh cng 609 H s DC x1 khng thnh cng 610 H s DC tng x10 khng thnh cng 611 H s DC x100 khng thnh cng 612 Ngun 500 nA li

BT o lng in t 613 Ngun 5 uA li 614 DC 1000V li 615 Ngun 10 uA li li 616 Dng DC li 617 Ohms 100 UA li 618 in p DC cao suy hao li 619 Ohms 1 mA ngun li 620 AC rms li 621 AC rms y thang li 622 B m tn s li 623 Khng th hiu chnh Precharge 624 Khng th cm nhn c tn s dng 625 Vi x l I / O khng phn hi 626 Vi x l I / O li t kim tra Li hiu chnh


Cc li sau y cho thy li c th xy ra trong mt hiu chun 701 Bo v hiu chnh v hiu ha bng jumper c im bo v hiu chun c v hiu ha vi mt jumper bn trong vn nng k. Khi p dng, li ny s xy ra khi c ngun cnh bo bn rng vn

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nng k khng an ton. 702 Bo v hiu chnh Vn nng ny c bo mt trc hiu chnh. 703 M bo v khng hp l Mt m bo v hiu chun khng hp l nhn c c gng bo v hay ph bo v vn nng k. Bn phi s dng cng mt m hy bo v vn nng k nh tng bo v n, v ngc li. Cc m bo v c th cha ln n 12 k t ch v s. K t u tin phi l mt ch ci. 704 M bo mt qu di Mt m bo mt c nhn trong c hn 12 k t. 705 Hiu chnh b hy b Mt hiu chnh trong tin trnh b hy b khi bn bm phm bt k ca bng iu khin pha trc,gi yu cu xa, hoc thay i trng thi a phng / xa ca vn nng k. 706 Gi tr hiu chun ra khi phm vi Gi tr hiu chun quy nh (CALibration:VALue) l khng hp l vi chc nng v phm vi hin ti 707 Tn hiu o cn hiu chnh vt phm vi Gi tr hiu chun quy nh (CALibration:VALue) khng ph hp vi tn hiu c cp cho vn nng k. 708 Tn s tn hiu hiu chnh vt phm vi Cc tn s tn hiu u vo cho mt hiu chun ac khng ph hp vi tn s u vo yu cu cn chnh. 709 Khng hiu chnh cho chc nng hoc thang o ny Bn khng th thc hin hiu chun cho dng ac, thi gian, lin tc, diode, t l, hoc thang trn 100 M. 710 iu chnh y thang ra khi phm vi 720

BT o lng in t Hiu chnh b DCV ra khi phm vi 721 Hiu chnh b DCI ra khi phm vi 722


Hiu chnh b RES ra khi phm vi 723 Hiu chnh b FRES ra khi phm vi 724 Tr khng m rng t iu chnh khng thnh cng 725 iu chnh vt phm vi 500VDC 730 DAC khng thnh cng 731 iu chnh A/D vt phm vi 732 AC - DAC t khng thnh cng 733 Tn s thp AC hi t khng thnh cng 734 iu chnh tn s thp AC vt phm vi 735 iu chnh nhiu AC rms vt phm vi 736 iu chnh tuyn tnh thang o th 100 AC rms khi phm vi 740 Tng kim tra hiu chnh khng thnh cng, trng thi bo v 741 Tng kim tra hiu chnh khng thnh cng, d liu chui 742 Tng kim tra hiu chnh khng thnh cng, iu chnh DCV 743 Tng kim tra hiu chnh khng thnh cng, iu chnh DCI 744 Tng kim tra hiu chnh khng thnh cng, iu chnh RES 745

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Tng kim tra hiu chnh khng thnh cng, iu chnh FRES 746 Tng kim tra hiu chnh khng thnh cng, iu chnh AC 747 Tng kim tra hiu chnh, a ch GPIB 748 Tng kim tra hiu chnh khng thnh cng, d liu ni b

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