Manuale d’uso / di manutenzione del prodotto Module SCXI-1503 del fabbricante National Instruments
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SCXI TM SCXI-1503 User Manual Mar ch 2007 374271A-01.
Support Worldwide Technical Support and Product Info rmation ni.com National Instruments Corporate Headquarters 11500 North Mopac Expressway Aust in, Texas 78759-3504 USA Tel: 512 683 0100 Worldwide O.
Important Information Warranty The SCXI-1503 is warranted against defects in materials and wo rkma nship for a p eriod of one year from the date of shipment, as evidenced by receipts or other documentati on. National Instruments will, at its option, repair or replace equipment that proves to be defective during the warranty period.
Conventions The follo wing con ve ntions are used in this manual: < > Angle brackets that cont ain numbers s eparated by an ellipsis represent a range of v alues associated with a bit or signal name—for example, P0.<3..0>. » The » symbol leads you through nested menu items and dial og box options to a final action.
© National Instruments Cor poration v SCXI-1503 User Manual Contents Chapter 1 About the SCXI-1503 What You Need to Get Started .............. .............. ........... .............. ............ .............. ....... 1-1 National Instruments D ocumentatio n .
Contents SCXI-1503 User Manual vi ni.com Chapter 4 Theory of Operation Rear Signal Connector, SCX Ibus Connector, an d SCXIbus Interface .................... ...... 4-3 Digital Control Circuitry .......... ........ ............ ........... ...........
Contents © National Instruments Corpor ation vii SCXI-1503 User Manual Appendix A Specifications Appendix B Removing the SCXI-1503 Appendix C Common Questions Glossary Index Figures Figure 2-1. 4-Wire Resistive Sensor Connected in a 4-Wire Confi guration .
Contents SCXI-1503 User Manual viii ni.com Tables Table 1-1. Supported SCXI-1503 Terminal Bloc ks ................ ......................... ...... 1-4 Table 2-1. Front Signal Pin Assignments ..... .............. ............ ........... .............
© National Instruments Corpor ation 1-1 SCXI-1503 User Manual 1 About the SCXI-1503 This manual describes the electrical and mechanical aspects of the SCXI-1503 module and contain s inform ation concerning its in stallation and operation.
Chapter 1 About the SCXI-1503 SCXI-1503 User Manual 1-2 ni.com – One of the following: • SCXI-1600 • E/M Series D A Q de vice – Computer – Cabling, cable adapter , and sensors as required for your application ❑ Software – NI-D A Q 8.
Chapter 1 About the SCXI-1503 © National Instruments Corpor ation 1-3 SCXI-1503 User Manual • SCXI or PXI/SCXI chassis manual—Read this manual for maintenance informatio n on the chassis and for installation instructions. • The DAQ Getting Started Guide —This document has inform ation on installing NI-DA Q and the E/M Series D A Q device.
Chapter 1 About the SCXI-1503 SCXI-1503 User Manual 1-4 ni.com Installing Application Software, NI-DAQ, and the E/M Series DAQ Device Refer to the DAQ Getting Started Guide packaged with the NI-DAQ software to install your application so ftware, NI-DAQ driver soft ware, and the DAQ device to w hich you will connect t he SCXI-1503.
Chapter 1 About the SCXI-1503 © National Instruments Corpor ation 1-5 SCXI-1503 User Manual V erifying the SCXI-1503 Installation Refer to the SCXI Quick Start G uide , for details about testi ng the SCXI chassis and module installation in softw are.
© National Instruments Corpor ation 2-1 SCXI-1503 User Manual 2 Connecting Signals This chapter describes the input and output signal connect ions to the SCXI-1503 module with the m odule front connector and rear signal connector.
Chapter 2 Connecti ng Signals SCXI-1503 User Manual 2-2 ni.com Note Exceeding the differential or common-mode input channe l ranges res ults in a distorted signal measurement, and can also in crease the settling time requirement of the connected E/M Series D A Q device.
Chapter 2 Connecting Signals © National Instruments Corpor ation 2-3 SCXI-1503 User Manual 4-Wire Configuration The 4-wire configuration, also referred to as a Kelvin connection, is shown in Figure 2-1.
Chapter 2 Connecti ng Signals SCXI-1503 User Manual 2-4 ni.com 2-Wire Configuration The basic 2-wire configuration is shown in Figure 2-2. In th is configuration an error voltage ( V E ) is introduced into the measurement equal to the excitation current ( I EX ) times the su m of the two lead resistances, R L1 and R L2 .
Chapter 2 Connecting Signals © National Instruments Corpor ation 2-5 SCXI-1503 User Manual 3-Wire Resistive Sensor Configuration If you are using a 3-wire resi stive se nsor, you can reduce the error voltage by one-half over the 2-wire measur ement by connecting the device as shown in Figure 2 -3.
Chapter 2 Connecti ng Signals SCXI-1503 User Manual 2-6 ni.com Lead-Resistance Compensation Using a 3-Wire Resistive Sensor and T wo Matched Current Sources You can compensate for the errors introduced by lead-resistance voltage drops by using a 3-wire resistive sens or and two matched current sources connected as shown in Figure 2-4.
Chapter 2 Connecting Signals © National Instruments Corpor ation 2-7 SCXI-1503 User Manual In this configuration, the lead -resistance voltage drop a cross R L3 is con verted into a common-mode voltage th at is rejected b y the diff erential amplifier .
Chapter 2 Connecti ng Signals SCXI-1503 User Manual 2-8 ni.com Table 2-1. Front Signal Pin Assignments Front Connect or Diagram Pin Number Column A Column B Column C 32 GND AI0– AI0+ 31 GND AI1– A.
Chapter 2 Connecting Signals © National Instruments Corpor ation 2-9 SCXI-1503 User Manual Table 2-2. Signal Descriptions Pin Signal Na me Description A1 +5 V +5 VDC Source—Used to po wer circuitry on the terminal block. 0.1 mA of source not protected.
Chapter 2 Connecti ng Signals SCXI-1503 User Manual 2-10 ni.com Rear Signal Connector Table 2-3 shows the SCXI-1503 module rear signal con nector pin assignments.
Chapter 2 Connecting Signals © National Instruments Corpor ation 2-11 SCXI-1503 User Manual Rear Signal Connector Descriptions The rear signal connector on the cabled module is the interface betw een the DAQ device and all modules in the SCXI chassis.
Chapter 2 Connecti ng Signals SCXI-1503 User Manual 2-12 ni.com 26 SER DA T OU T P0.4 Output Serial data out—thi s signal taps into the SCXIbus MISO line to accept serial output data from a module.
© National Instruments Corpor ation 3-1 SCXI-1503 User Manual 3 Configuring and T esting This chapter discusses configuring th e SCXI-1503 in MAX using NI-DAQmx, creating and testing a virtu al channel, global channel, and/or task. Notes Y ou must have NI-D A Qmx 8.
Chapter 3 Configur ing and T esting SCXI-1503 User Manual 3-2 ni.com Input Coupling The front end of the SCXI-1503 includ es a software configurable switch that allows you t o programmatical ly connect the input channels of the SCXI-1503 to either the front co nnector or internal groun d.
Chapter 3 Configurin g and T esting © National Instruments Corpor ation 3-3 SCXI-1503 User Manual NI-DAQmx Using NI-DAQmx, you can configure softwa re settings such as sensor typ e and gain/input sig.
Chapter 3 Configur ing and T esting SCXI-1503 User Manual 3-4 ni.com selecting channels. If you are creat ing a channel, you can only select one channel. Click Next . 7. Name the task or channel and click Finish . 8. Select the channel(s) you want to configure.
Chapter 3 Configurin g and T esting © National Instruments Corpor ation 3-5 SCXI-1503 User Manual 6. Click the Test button. 7. Click the Start button. 8. After you hav e completed verifying the channels, click the Stop button. Y ou have no w verif ied the SCXI-1503 configuration and signal co nnection.
© National Instruments Corpor ation 4-1 SCXI-1503 User Manual 4 Theor y of Operation This chapter provides a brief overview and a detailed discu ssion of the circuit features of the SCXI-1503 module.
Chapter 4 Theory of Operation SCXI-1503 User Manual 4-2 ni.com Figure 4-1. Block Diagram of SCXI-1503 AI 15 + AI 15 – Calibration Source SCXIbus Interface CJSENSOR F ront Signal Connector Rear Signal Connector 32-to-1 Mux Input Protection and Lowpass Filter Switch Switch Switch Mux Inst.
Chapter 4 Theory of Ope ration © National Instruments Corpor ation 4-3 SCXI-1503 User Manual The major components of the SCXI-1503 modul es are as follo ws: • Rear signal connector • SCXIb us con.
Chapter 4 Theory of Operation SCXI-1503 User Manual 4-4 ni.com The CJ SENSOR input channel is used to read the sensor temperature from the terminal block.
Chapter 4 Theory of Ope ration © National Instruments Corpor ation 4-5 SCXI-1503 User Manual The module includes first-in first-out (FIFO) memory fo r storing the channel scan list defined in your appli cation code. NI-D A Q dri vers load the FIFO based on the channel assig nments you make in your application.
Chapter 4 Theory of Operation SCXI-1503 User Manual 4-6 ni.com changes in resistance, you must use special conf igurations that minimize measured errors caused by lead-wire resistance. R TD Measurement Errors Because the RTD is a resistive device, you must pass a cu rrent through the device and monitor the resultin g volta ge.
Chapter 4 Theory of Ope ration © National Instruments Corpor ation 4-7 SCXI-1503 User Manual defined as the change in RTD resistance from 0 to 100 ° C, divided by the resistance at 0 ° C, divided by 100 ° C: where R 100 is the resistance of the R TD at 100 ° C.
Chapter 4 Theory of Operation SCXI-1503 User Manual 4-8 ni.com Although the resistance-temperature curv e is relativ ely linear , accurately con verting measured resistance to temperature requires curve fitting.
Chapter 4 Theory of Ope ration © National Instruments Corpor ation 4-9 SCXI-1503 User Manual For temperatures abo v e 0 ° C, coef ficient C equals 0, reducing this equation to a quadratic.
Chapter 4 Theory of Operation SCXI-1503 User Manual 4-10 ni.com Thermistors A thermistor is a piece of semiconductor made from metal oxides, pressed into a small bead, disk, wafer, or other shape, sintered at high temperatures, and finally coated with epoxy or glass.
Chapter 4 Theory of Ope ration © National Instruments Corpor ation 4-11 SCXI-1503 User Manual Figure 4-4. Resistanc e-T emperature Cur ve for a 2,252 Ω Thermistor The thermistor has been used primaril y for high-resolution measurem ents ov er limited temperature ranges.
Chapter 4 Theory of Operation SCXI-1503 User Manual 4-12 ni.com The maximum resistance of the therm ist or is determined from the current excitation v alue and the maximum voltage range of the input device. When using the SCXI-1503, the maximum measurable resistance is 100 k Ω .
Chapter 4 Theory of Ope ration © National Instruments Corpor ation 4-13 SCXI-1503 User Manual where T (°K) is the temperature in de grees K elvin, equal to T (°C) + 273.
© National Instruments Corpor ation 5-1 SCXI-1503 User Manual 5 Using the SCXI-1503 This chapter makes suggestions for developing you r application and provides basic info rmation regarding cal ibration. Developing Y our Application in NI-DAQmx Note If you are not using an NI ADE, using an NI ADE prior to version 8.
Chapter 5 Using the SCXI-1503 SCXI-1503 User Manual 5-2 ni.com Figure 5-1. T ypical Program Flowchart for Voltage Measurement Channels Ye s Create Channel Adjust Timing Settings Create a T ask Program.
Chapter 5 Using the SCXI-1503 © National Instruments Corpor ation 5-3 SCXI-1503 User Manual General Discussion of T ypical Flowchart The following sections b riefly discuss some considerations for a few of the steps in Figure 5-1.
Chapter 5 Using the SCXI-1503 SCXI-1503 User Manual 5-4 ni.com time. For continuous acquisition, you must use a while loop around the acquisition componen ts e ven if you configured the task for continuous acquisition using MAX or the DA Q Assistant.
Chapter 5 Using the SCXI-1503 © National Instruments Corpor ation 5-5 SCXI-1503 User Manual Analog Input»General Properties»Advanced» Gain and Offset»Ga in Value AI.Gain Specif ies a g ain factor to apply to the signal condition ing portion of the channel .
Chapter 5 Using the SCXI-1503 SCXI-1503 User Manual 5-6 ni.com Analog Input»Temperature» RTD»Custom»A, B, C AI.R TD.A AI.R TD.B AI.R TD.C Specifies the A, B, or C constant of the Callendar-V an D usen equation when using a custom R TD type. Ye s Analog Input»General Properties»Si gnal Conditioning»Resistance Configuration AI.
Chapter 5 Using the SCXI-1503 © National Instruments Corpor ation 5-7 SCXI-1503 User Manual Note This is not a complete list of NI-DA Qmx properties and does not include ev ery property you may need to configure your application. It is a representativ e sample of important properti es to configure for volt age measurements.
Chapter 5 Using the SCXI-1503 SCXI-1503 User Manual 5-8 ni.com charts, graphs, slide controls, and ga uge indicators. NI ADEs hav e tools that allow you to easily sa ve the data to f iles such as spread sheets for easy viewing, ASCII files for uni versality , or binary files for smaller file sizes.
Chapter 5 Using the SCXI-1503 © National Instruments Corpor ation 5-9 SCXI-1503 User Manual Create V irtual Channel(s) DAQMX Create Virtual Channel.vi located on the Functions»All Functions» NI Measurements»DAQmx - Data Acquisition subpalette—Use this VI to add virtual channels to the task.
Chapter 5 Using the SCXI-1503 SCXI-1503 User Manual 5-10 ni.com Using a NI-DAQmx Channel Property Node in LabVIEW You can use property no des in LabVIEW to manual ly configure the channels. To create a LabVIEW prope rty node, complete the following steps: 1.
Chapter 5 Using the SCXI-1503 © National Instruments Corpor ation 5-11 SCXI-1503 User Manual Note Refer to the LabVIEW He lp for information about pr operty nodes and specific NI-D A Qmx proper ties. Specifying Channel St rings in NI-DAQmx Use the channel input of DAQmx Create Channel to specify the SCXI-1503 channels.
Chapter 5 Using the SCXI-1503 SCXI-1503 User Manual 5-12 ni.com Note Refer to the NI LabWindows/CVI Help for more inform ation on creating NI-D A Qmx tasks in LabW indo ws/CVI and NI-D A Qmx prop erty information. Measurement Studio (Visual Basic 6, .
Chapter 5 Using the SCXI-1503 © National Instruments Corpor ation 5-13 SCXI-1503 User Manual Programmable NI-D AQmx Properties All of the different ADEs that configure the SCXI-1503 access an underlying set of NI-DAQmx prop erties. Tables 5-1 through 5-4 provide a list of s ome of the p roperties that configure the SCXI-1503.
Chapter 5 Using the SCXI-1503 SCXI-1503 User Manual 5-14 ni.com The functions that are requ ired for externally calib rating the SCXI-1503 are av ailable in NI-D A Qmx 8.1 o r later . Refer to the NI-DAQmx Help for details about these functions. Most external calibration documents for SCXI modules are av ailable to download from ni.
© National Instruments Corpor ation A-1 SCXI-1503 User Manual A Specifications This appendix lists the specifications for the SCXI-1503 modules. These specif ications are typical at 25 ° C unless otherwise noted. Analog Input Input Characteristics Number of channels .
Appendix A Specifications SCXI-1503 User Manual A-2 ni.com Gain = 100 Calibrated 1 .............. ............ ......±25 μ V max ±10 μ V typ With autozero enabled 2 ........ ....±10 μ V max ±5 μ V typ Gain error (relative to calibration refe rence) Gain = 1 or 100 Calibrated 1 .
Appendix A Specifications © National Instruments Corpor ation A-3 SCXI-1503 User Manual CMRR characteristics (DC to 60 Hz) Gain 1 ....................... ........... ............ –75 dB min –90 dB typ Gain 100 ................... ........... ....
Appendix A Specifications SCXI-1503 User Manual A-4 ni.com Gain temperature coefficient (gain 1 or 100) ...................... .............. ....±15 ppm/ ° C max ±5 ppm/ ° C typ Excitation Channels ... ........... ............... .............. .
Appendix A Specifications © National Instruments Corpor ation A-5 SCXI-1503 User Manual Physical Figure A-1. SCXI-1503 Dimensions Weight .................... .............. ........... ....... 745 g (26.3 oz) Maximum W orking Voltage Maximum working voltage refers to the signal voltage plus the common-mode voltage.
Appendix A Specifications SCXI-1503 User Manual A-6 ni.com Safety This product is designed to meet the requirements of the following standards of safety for electrical e quipment for measurement, cont.
© National Instruments Corpor ation B-1 SCXI-1503 User Manual B Removing the SCXI-1503 This appendix explains ho w to remove the SCXI-1503 from MAX and an SCXI chassis or PXI/SC XI combination chassis. Removing the SCXI-1503 from MAX T o remov e a module from MAX, complete the follo wing steps after launching MAX: 1.
Appendix B Removing the SCXI-1503 SCXI-1503 User Manual B-2 ni.com 4. Rotate the thumbscre ws that secu re the SCXI-1503 to the chassis counterclockwise until they are loose, but do not completely remove the thumbscrews. Remov e the SCXI-1503 by pulling steadily on both thumbscrews until the module slides comp letely out.
© National Instruments Corpor ation C-1 SCXI-1503 User Manual C Common Questions This appendix lists com mon questions related to the u se of the SCXI-1503. Which version of NI-D AQ w orks with the SCXI-1503, and how do I get the most current v ersion of NI-D AQ? Y ou must hav e NI-D A Q 8.
Appendix C Comm on Questions SCXI-1503 User Manual C-2 ni.com Can I connect N current-output ch annels in parallel to cr eate a precision curr ent sour ce that pr ovides N × 100 μ A? Y es, you can connect the current output in parallel.
Appendix C Common Questions © National Instruments Corpor ation C-3 SCXI-1503 User Manual Does short-circuiting a curr ent-out put channel d o any damage to the SCXI-1503? No.
© National Instruments Corpor ation G-1 SCXI-1503 User Manual Glossar y Symbol Pref ix V alue µ micro 10 –6 m milli 10 –3 k kilo 10 3 Mm e g a 1 0 6 Numbers/Symbols % percent + positi v e of, or.
Glossary SCXI-1503 User Manual G-2 ni.com B bit one binary digit, either 0 or 1 C CE European emissions control standard C GND chassis ground signal channel pin or wire lead to which you apply , or from which you read, an analog or digital si gnal. Analog sign als can be single-ended or dif ferential.
Glossary © National Instruments Corpor ation G-3 SCXI-1503 User Manual D GND digital ground signal differential ampl ifier an amplifier with two input terminals, neither of which are ti ed to a groun.
Glossary SCXI-1503 User Manual G-4 ni.com J jumper a small rectangular device used to connect two adjacent posts on a circuit board. Jumpers are used on so me SCXI modul es and terminal blocks to either select certain parameters or enabl e/disable circui t functionality .
Glossary © National Instruments Corpor ation G-5 SCXI-1503 User Manual O output voltage compliance the largest v oltage that can be gene rated across the output of a current source without the curren.
Glossary SCXI-1503 User Manual G-6 ni.com sensor a type of transducer that con verts a phys ical phenomenon into an electrical signal SER CLK serial clock signal u sed to sync hronize digit al data tr.
Glossary © National Instruments Corpor ation G-7 SCXI-1503 User Manual VI virtual instrument—(1) a combination of hardware and/or software elements, typically used with a PC, th at has the function.
© National Instruments Corpor ation I-1 SCXI-1503 User Manual Index Numerics 2-wire configuration of resistive devices, 2-4 3-wire resistive sensor connected in 2-wire configuration, 2-5 lead-resista.
Index SCXI-1503 User Manual I-2 ni.com conventions used in the manual, iv creating a task DAQ Assistant, 5-3 programmatically, 5-3 current output channels, questions about, C-1, C-3 current sources, o.
Index © National Instruments Corpor ation I-3 SCXI-1503 User Manual NI-DAQmx channel property node, 5-10 program flowchar t (figure), 5- 2 programmable properties, 5-13 specifying channel strings, 5-.
Index SCXI-1503 User Manual I-4 ni.com signals verifying, 3-4 NI-DAQmx, 3-4 software, NI-DAQ v ersion required, C-1 specifications analog input, A-1 CE compliance, A-6 electromagnetic comp atibility, .
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 Module SCXI-1503 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 Module SCXI-1503 - in questo modo è possibile verificare se l’apparecchio soddisfa le tue esigenze. Esplorando le pagine segenti del manuali d’uso National Instruments Module SCXI-1503 imparerai tutte le caratteristiche del prodotto e le informazioni sul suo funzionamento. Le informazioni sul National Instruments Module SCXI-1503 ti aiuteranno sicuramente a prendere una decisione relativa all’acquisto.
In una situazione in cui hai già il National Instruments Module SCXI-1503, 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 Module SCXI-1503.
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 Module SCXI-1503. Quasi sempre, ci troverai Troubleshooting, cioè i guasti più frequenti e malfunzionamenti del dispositivo National Instruments Module SCXI-1503 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.
