Manuale d’uso / di manutenzione del prodotto NI 9235 del fabbricante National Instruments
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OPERATING INSTRUCTIONS AND S PECIFICATIONS NI 9235/9236 8-Channel, 24-Bit Quarter-Brid ge Analog Input Module ni.com/manuals Deutsch Français.
NI 9235/9236 2 ni.com This doc u ment describes ho w to u se the National Instr u ments 9235 and National Instr u ments 9236 and incl u des specif ications and terminal assignments. In t his doc u ment, the NI 9235 and NI 9236 are referred to incl u si v ely as the NI 9235/9236.
© National Instruments Co rp. 3 NI 9235/9236 Safety Guidelines Operate the NI 9235/9236 only as described in these operating instr u ctions. Hot Surface This icon denotes that the component may be hot. T o u ching this component may res u lt in bodily inj u ry .
NI 9235/9236 4 ni.com Caution S u bstit u tion of components may impair s u itability for Class I, Division 2. Caution For Zone 2 applications, install the system in an enclos u re rated to at least IP 54 as defined b y IEC 60529 and EN 60529 . Caution For Zone 2 applications, connected signals m u st be within the following limit: Capacitance .
© National Instruments Co rp. 5 NI 9235/9236 Special Conditions fo r Marine Ap plications Some mod u les are Lloyd’ s Register (LR) T ype Approv ed for marine applications. T o verify Llo yd’ s Register cert if ication, visit ni.com/certification and search for the LR certificate, or look for the Lloyd’ s Register mark on the mod u le.
NI 9235/9236 6 ni.com Connecting the NI 9235/9236 The NI 9235/9236 has a 24-terminal detachable spring-terminal connector that provides con nections for 8 analog inp u t channels.
© National Instruments Co rp. 7 NI 9235/9236 Yo u can connect a q u arter- bridge sensor to each channel. Each channel has an EXC termi nal that pro vides the exc itation v oltage stim u l u s, an AI terminal tha t meas u res the bridge voltage, and an RC terminal that pro vides the q u arter -bridge completion.
NI 9235/9236 8 ni.com Connecting Wires to the NI 9235/9236 Conn ector Use a flathead scre wdriv er with a blade smaller than 2.3 × 1.0 mm (0.09 × 0.04 in.
© National Instruments Co rp. 9 NI 9235/9236 Wiring for High-Vib ration Applications If an application is s u bject to high vibrat ion, National Instr u ments recommends that yo u u se the NI 9965 backshell kit to protect the connections. Re fer to Fig u re 4 for an ill u stration of the NI 9965 connector backshell.
NI 9235/9236 10 ni.com NI 9235/9236 Circuitry The NI 9235/9236 is isolated from earth gro u nd. Ho we ver , the individ u al channels are not isolated from ea ch other .
© National Instruments Co rp. 11 NI 9235/9236 Figure 5. Input Cir cuitry for One Channel of the NI 9235 EXC AI RC + – Bridge Completion Re s i s tor Filtered Differenti a l Amplifier 2.
NI 9235/9236 12 ni.com Figure 6. Input Cir cuitry for One Channel of the NI 9236 The NI 9235/9236 also incl u des filt ers to pre vent al iasing. The filters on the NI 9235/9236 f ilter according to the sampling rate. Refer to th e Understanding NI 9235/9236 Filtering section for more informatio n abo u t filte ring.
© National Instruments Co rp. 13 NI 9235/9236 Q u arter -bridge meas u rements are inherently sensitiv e to acc u racy degradation d u e to the le ad resistance of wiring from the sensor to the meas u rement de vice. For a give n change in the gage resistance, the total ef fectiv e resistance cha nges slightly less.
NI 9235/9236 14 ni.com Sh u nt calibration sim u lates strain in p u t by changing the resistance of an arm in the bridge b y a known amo u nt. By sh u nting, or connecting, a large resistor across one arm of the bridge, a specif ic change occ u rs in the bridge v oltage ratio.
© National Instruments Co rp. 15 NI 9235/9236 Understanding NI 9235/9236 Filtering The NI 9235/9236 u ses a combination of analog and digital filte ring to pro vide an acc u rate representation of in-band signals while rejecting o u t-of-band signals.
NI 9235/9236 16 ni.com Figure 7. T ypical Passband Response for the NI 9235/9236 Fr e qu ency (kHz) 5 4 0.025 0.000 –0.025 –0.050 3 2 1 0 G a in (dB).
© National Instruments Co rp. 17 NI 9235/9236 Stopband The filter signif icantly atten u ates all signals abo ve the stop band freq u ency . The primary goal of the filter is to pre vent aliasing. Therefore, the stopband freq u ency scales precisel y with the data rate.
NI 9235/9236 18 ni.com the mod u les m u st share a single master timebase so u rce. Refer to the software help for information abo u t conf ig u ring the master timebase so u rce for the NI 9235/9236. V isit ni.com/info and enter c s erie s doc for information abo u t C Series doc u mentation.
© National Instruments Co rp. 19 NI 9235/9236 Sleep Mode This mod u le s u pports a low-po wer sleep mode. S u pport for sleep mode at the system le vel depe nds on the chassis that the mod u le is pl u gged into. Refer to the chassis man u al for information abo u t s u pport for sleep mode.
NI 9235/9236 20 ni.com Specifications The follo wing specifications a re typical for the range – 40 to 70 °C u nless otherwise note d. The specifications are the same for the NI 9235 and the NI 9236 u nless otherwise noted. Input Characteristics N u mber of channels .
© National Instruments Co rp. 21 NI 9235/9236 Data rate range ( f s ) u sing internal master tim ebase Minim u m ...................... ........... ... 794 S/s Maxim u m ......... ......... ............ ..... 10 kS/s Data rate range ( f s ) u sing external master timebase Minim u m .
NI 9235/9236 22 ni.com Acc u racy , NI 9235 Stability , NI 9235 Gain drift .. ........... ......... ........ 6 ppm/°C Offset drift ........... ......... ........ 2.2 μ V/V/°C Measurement Conditions Per cent of Reading * (Gain Error) Per cent of Range †, ‡ (Offset Error) 30 days after ca l.
© National Instruments Co rp. 23 NI 9235/9236 Acc u racy , NI 9236 Stability , NI 9236 Gain drift .. ........... ......... ........ 6 ppm/°C Offset drift ........... ......... ........ 1.7 μ V/V/°C Measurement Conditions Per cent of Reading * (Gain Error) Per cent of Range †, ‡ (Offset Error) 30 days after ca l.
NI 9235/9236 24 ni.com Channel-to-channel ma tching (calibrated) Phase nonlineari ty f in = 0 to 1 kHz..... ........... ......... ... ±0.002° f in = 0 to 4 kHz..... ........... ........... . ±0.1° Inp u t delay .......... ........... ......... ...
© National Instruments Co rp. 25 NI 9235/9236 Alias-free bandwidth ..... ......... .......... 0.45 · f s Oversample rate ......... ......... ........... ... 64 · f s Rejection at o versa mple rate 1 (f s = 10 kS/s) ......... ........... ......... .
NI 9235/9236 26 ni.com Crosstalk ( f in = 1 kHz) .......... ............ –100 dB Common-mode vo ltage, all signals to earth gro u nd ......... ........ ±60 VDC CMRR ( f in = 0 to 60 Hz) NI 9235 ........... ........... ............ ..... 120 dB NI 9236 .
© National Instruments Co rp. 27 NI 9235/9236 Shunt Calibration Characteristics Sh u nt calibration acc u rac y Resistance NI 9235 ........... ........... ............ ..... 50 k Ω NI 9236 ........... ........... ............ ..... 100 k Ω O u tp u t val u e NI 9235 .
NI 9235/9236 28 ni.com Excitation Characteristics Excitation type .... ........... ......... .......... Consta nt voltage Excitation v al u e NI 9235 ......... ...................... ........ 2.0 V ± 1% NI 9236 ......... ...................... ......
© National Instruments Co rp. 29 NI 9235/9236 Thermal dissipation (at 70 °C) NI 9235 Activ e mode .... ........... .......... 735 mW max Sleep mode ........ ......... ......... . 2 5 μ W max NI 9236 Activ e mode .... ........... .......... 675 mW max Sleep mode .
NI 9235/9236 30 ni.com Isolation Channel-to-channel ............ ........ None Channel-to-earth gro u nd Contin u o u s .... ........... ......... ... 60 VDC, Meas u rement Category I W i thstand .
© National Instruments Co rp. 31 NI 9235/9236 Safety Standards This prod u ct is designed to meet the req u ire ments of the follo wing standards of safety for electrical eq u ipment for meas u remen.
NI 9235/9236 32 ni.com Environmental National Instr u ments C Series mod u les are intend ed for indoor u se only b u t may be u sed o u tdoors if installed in a s u itabl e enclos u re. Refer to th e man u al for the chassis yo u are u sing for more information abo u t meeting th ese specif ications.
© National Instruments Co rp. 33 NI 9235/9236 Shock and Vibration T o meet these specif ications, yo u m u st panel mo u nt the system and u se the NI 9965 backshell to protect the connectio ns. Operating vibration Random (IEC 60068-2-64)......... 5 g rms , 10 to 500 Hz Sin u soidal (IEC 60068-2-6) .
NI 9235/9236 34 ni.com Note For EMC compliance, operate this de vice with shielded cabling. CE Compliance This prod u ct meets the essent ial req u irem ents of app licable E u ropean directi ves, as .
© National Instruments Co rp. 35 NI 9235/9236 For additional en vironmental information, refer to the NI and the Environment W eb page at ni.com/environment . This page contains the en vironmental reg u lations and direct i ves with which NI complies, as well as othe r en vironmental information not incl u ded in this doc u ment.
NI 9235/9236 36 ni.com Calibration Yo u can obtain the calibration cert ificate and information abo u t calibration services for th e NI 9235/9236 at ni.com/ calibration . Calibration interval ............... ........... . 1 year Where to Go for Support The National Instr u ments W eb site is yo u r complete reso u rce for technical s u pport.
© National Instruments Co rp. 37 NI 9235/9236 and follo w the calling instr u ctions or dial 512 795 8248. F or telephone s u pport o u tside the United Stat es, contact yo u r local branch off ice: .
© 2008 National I nstruments Corp. All rights reserved. 374645A-01 Jun08 National Instruments, NI, n i.com, and LabVIEW are trademarks of National Instrument s Corporation. Refer to the Terms of Use section on ni.com/legal for more information about National Instruments t rademarks.
Un punto importante, dopo l’acquisto del dispositivo (o anche prima di acquisto) è quello di leggere il manuale. Dobbiamo farlo per diversi motivi semplici:
Se non hai ancora comprato il National Instruments NI 9235 è un buon momento per familiarizzare con i dati di base del prodotto. Prime consultare le pagine iniziali del manuale d’uso, che si trova al di sopra. Dovresti trovare lì i dati tecnici più importanti del National Instruments NI 9235 - in questo modo è possibile verificare se l’apparecchio soddisfa le tue esigenze. Esplorando le pagine segenti del manuali d’uso National Instruments NI 9235 imparerai tutte le caratteristiche del prodotto e le informazioni sul suo funzionamento. Le informazioni sul National Instruments NI 9235 ti aiuteranno sicuramente a prendere una decisione relativa all’acquisto.
In una situazione in cui hai già il National Instruments NI 9235, ma non hai ancora letto il manuale d’uso, dovresti farlo per le ragioni sopra descritte. Saprai quindi se hai correttamente usato le funzioni disponibili, e se hai commesso errori che possono ridurre la durata di vita del National Instruments NI 9235.
Tuttavia, uno dei ruoli più importanti per l’utente svolti dal manuale d’uso è quello di aiutare a risolvere i problemi con il National Instruments NI 9235. Quasi sempre, ci troverai Troubleshooting, cioè i guasti più frequenti e malfunzionamenti del dispositivo National Instruments NI 9235 insieme con le istruzioni su come risolverli. Anche se non si riesci a risolvere il problema, il manuale d’uso ti mostrerà il percorso di ulteriori procedimenti – il contatto con il centro servizio clienti o il servizio più vicino.
