National Instruments SCXI-1520 User Manual Download

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SCXI

SCXI-1520 User Manual

SCXI-1520 User Manual

May 2009
372583E-01

Summary of Contents for SCXI-1520

Page 1: ...SCXI TM SCXI 1520 User Manual SCXI 1520 User Manual May 2009 372583E 01...

Page 2: ...3400 Lebanon 961 0 1 33 28 28 Malaysia 1800 887710 Mexico 01 800 010 0793 Netherlands 31 0 348 433 466 New Zealand 0800 553 322 Norway 47 0 66 90 76 60 Poland 48 22 328 90 10 Portugal 351 210 311 210...

Page 3: ...toring in an information retrieval system or translating in whole or in part without the prior written consent of National Instruments Corporation National Instruments respects the intellectual proper...

Page 4: ...otes items that you must select or click in the software such as menu items and dialog box options Bold text also denotes parameter names italic Italic text denotes variables emphasis a cross referenc...

Page 5: ...5 Verifying the SCXI 1520 Installation in Software 1 6 Installing SCXI Using NI DAQmx in Software 1 6 Manually Adding Modules in NI DAQmx 1 6 Installing SCXI Using Traditional NI DAQ Legacy in Softwar...

Page 6: ...figuring Module Property Pages in Traditional NI DAQ Legacy 3 10 Creating a Strain Virtual Channel 3 11 Calibrating a Strain Virtual Channel 3 11 Verifying the Signal 3 12 Verifying the Signal in NI D...

Page 7: ...veloping Your Application in NI DAQmx 5 1 Typical Program Flowchart 5 2 General Discussion of Typical Flowchart 5 4 Creating a Task Using DAQ Assistant or Programmatically 5 4 Adjusting Timing and Tri...

Page 8: ...Performing Offset Null Compensation Using Traditional NI DAQ Legacy C API 5 34 Performing Shunt Calibration Using Traditional NI DAQ Legacy C API 5 34 Performing Acquisition Using Traditional NI DAQ...

Page 9: ...Figure 4 6 Half Bridge Type I Measuring Axial and Bending Strain 4 9 Figure 4 7 Half Bridge Type I Circuit Diagram 4 9 Figure 4 8 Half Bridge Type II Rejecting Axial and Measuring Bending Strain 4 11...

Page 10: ...tions 4 2 Table 4 2 Control Codes for Coarse and Fine Offset Null Potentiometers 4 26 Table 4 3 NI DAQmx Values Used to Determine Maximum Sample Rate in Multiplexed Mode 4 31 Table 4 4 NI DAQmx Values...

Page 11: ...14 terminal block you can do the following Connect sensors of all bridge configurations including quarter half and full bridge Set the DC voltage excitation between 0 and 10 V increments dependent upo...

Page 12: ...XI Quick Start Guide SCXI 1520 User Manual Documentation for your hardware Documentation for your software The optional accessories listed in Table 1 1 are available for the SCXI 1520 Table 1 1 Access...

Page 13: ...10 provides 96 eyelet type terminals for easy hook and solder signal connection and custom mass termination connectivity TBX 96 DIN rail mounted terminal block with 96 generic screw terminals One of t...

Page 14: ...documentation You may have both application software and NI DAQ software documentation National Instruments NI application software includes LabVIEW LabWindows CVI and Measurement Studio After you set...

Page 15: ...emoving equipment covers or connecting or disconnecting any signal wires Installing the SCXI 1520 Module into the SCXI Chassis Refer to the SCXI Quick Start Guide to install your SCXI 1520 module Conn...

Page 16: ...hassis Installing SCXI Using Traditional NI DAQ Legacy in Software Refer to the SCXI Quick Start Guide for information on installing modules using Traditional NI DAQ Legacy in software Manually Adding...

Page 17: ...the SCXI chassis is powered on Make sure all SCXI modules are properly installed in the chassis Refer to the SCXI Quick Start Guide for proper installation instructions Make sure the cable between the...

Page 18: ...cking the preceding items return to the Troubleshooting the Self Test Verification section and retest the SCXI chassis If these measures do not successfully configure the SCXI system contact NI Refer...

Page 19: ...the configured module is installed in the specified slot If not install the module by following the instructions in the Installing the SCXI 1520 Module into the SCXI Chassis section If the module is...

Page 20: ...unt calibration Refer to Chapter 4 Theory of Operation for a discussion of strain gauge concepts Refer to the SCXI 1314 Installation Guide for more signal connection information Notes The circuits in...

Page 21: ...e Note The value of the quarter bridge completion resistor R3 must equal the nominal resistance of the strain gauge NI recommends using a 0 1 precision resistor Quarter Bridge Type II This section pro...

Page 22: ...tion the R3 element is not bonded to the specimen Typically it is either physically close to the specimen or mounted on the same type material at the same temperature but is not under strain Figure 2...

Page 23: ...istors R3 is the active element measuring compression from Poisson effect R4 is the active element measuring tensile strain VEX is the excitation voltage RL is the lead resistance VCH is the measured...

Page 24: ...ge completion resistors R3 is the active element measuring compressive strain R4 is the active element measuring tensile strain VEX is the excitation voltage RL is the lead resistance VCH is the measu...

Page 25: ...element measuring tensile strain R3 is an active element measuring compressive strain R4 is an active element measuring tensile strain VEX is the excitation voltage RL is the lead resistance VCH is th...

Page 26: ...R2 is an active element measuring tensile Poisson effect R3 is an active element measuring compressive strain R4 is an active element measuring tensile strain VEX is the excitation voltage RL is the l...

Page 27: ...Poisson effect R2 is an active element measuring tensile strain R3 is an active element measuring compressive Poisson effect R4 is an active element measuring the tensile strain VEX is the excitation...

Page 28: ...er to Chapter 4 Theory of Operation for more information about using remote sense Wire the SCXI 1520 for remote sense as shown in Figure 2 8 Figure 2 8 Remote Sense Circuit Diagram Note If you use rem...

Page 29: ...e all signal connections The terminal assignments are as follows SX and SX are for analog input RSX and RSX are for remote sense PX and PX are for excitation output SCAX are for shunt calibration circ...

Page 30: ...D P1 P1 25 RSVD SCA1 SCA1 24 SCB2 S2 S2 23 SCB2 RS2 RS2 22 SCB3 P2 P2 21 SCB3 SCA2 SCA2 20 RSVD S3 S3 19 RSVD RS3 RS3 18 RSVD P3 P3 17 RSVD SCA3 SCA3 16 SCB4 S4 S4 15 SCB4 RS4 RS4 14 SCB5 P4 P4 13 SCB...

Page 31: ...nnectivity and communication between the SCXI 1520 and the connected E M Series DAQ device The rear signal connector is shown in Table 2 2 The rear signal connector allows the DAQ device to access all...

Page 32: ...ts Rear Connector Diagram Signal Name Pin Number Pin Number Signal Name 1 2 CH 0 3 4 CH 0 CH 1 5 6 CH 1 CH 2 7 8 CH 2 CH 3 9 10 CH 3 CH 4 11 12 CH 4 CH 5 13 14 CH 5 CH 6 15 16 CH 6 CH 7 17 18 CH 7 19...

Page 33: ...SCXI system are listed in Table 2 3 If the DAQ device is connected to the SCXI 1520 these digital lines are unavailable for general purpose digital I O Table 2 3 SCXI 1520 Communication Signals Pin SC...

Page 34: ...odule that the E M Series DAQ device has taken a sample and causes the module to advance channels 37 SER CLK EXTSTROBE EXTSTROBE Input Serial clock this signal taps into the SCXIbus SPICLK line to clo...

Page 35: ...he relationship between the settings and the measurements and how to configure settings in your application refer to Chapter 4 Theory of Operation Common Software Configurable Settings This section de...

Page 36: ...resistance as well as the quarter bridge completion resistance R3 R4 Table 3 1 shows the maximum allowable excitation voltages for standard bridge configurations and resistances Filter Bandwidth Filt...

Page 37: ...nal in microvolts is When you have determined the input signal voltage you can use the following equation to determine the appropriate gain If you are using a bridge based sensor use the manufacturer...

Page 38: ...sts the null potentiometers settings Refer to Chapter 4 Theory of Operation for more information Shunt Calibration Switches Shunt calibration switches A and B are software control settings that allow...

Page 39: ...d Note You cannot change the simultaneous sampling mode in MAX You must use an ADE such as LabVIEW or LabWindows CVI to configure the setting using NI DAQmx Channel Property Node Refer to your ADE hel...

Page 40: ...ride module properties The default bridge configuration for NI DAQmx is full bridge Voltage excitation configure using either NI DAQmx Task or NI DAQmx Global Channel You also can set the voltage exci...

Page 41: ...a new NI DAQmx strain global task or channel complete the following steps 1 Double click Measurement Automation on the desktop 2 Right click Data Neighborhood and select Create New 3 Select NI DAQmx...

Page 42: ...r other bridge based sensors To create an NI DAQmx Custom Voltage with Excitation Task or NI DAQmx Global Channel complete the following steps 1 Double click Measurement Automation on the desktop 2 Ri...

Page 43: ...on using functions in your application Most of these settings are available in module properties and or using virtual channels Bridge configuration configure using module properties virtual channels...

Page 44: ...e SCXI 1520 module you want to configure and select Properties Click General 2 If the module you are configuring is connected to an E Series DAQ device select that device by using Connected to If you...

Page 45: ...ation a Bridge type from the drop down menu b V init in volts c Lead Resistance in d Nominal Gauge in e Gauge Factor f Range min in g Range max in 8 Click Next 9 Enter the following information a What...

Page 46: ...hood 2 Click the next to NI DAQmx Tasks to expand the list of tasks 3 Click the task 4 Add or remove channels if applicable in the Channel List Click the Add Channels button shown at left and select t...

Page 47: ...system In a multichassis or remote chassis system the DAQ device channel x corresponds to chassis number n 1 where DAQ device channel x is used for scanning the nth chassis in the system scy is the S...

Page 48: ...erifying the channel click Close Using the Strain Calibration Wizard in NI DAQmx When using NI DAQmx you can perform an automated strain calibration on one or more channels in your task using the Stra...

Page 49: ...ed on the concept of a Wheatstone bridge A Wheatstone bridge is a network of four resistive legs One or more of these legs can be active sensing elements Figure 4 1 shows a Wheatstone bridge circuit d...

Page 50: ...ivided into multiple configuration types The orientation of the active elements and the kind of strain measured determines the configuration type NI supports seven configuration types in software Howe...

Page 51: ...are long RL can significantly impact measurement accuracy Rs is the shunt calibration resistor value U is the ratio of expected signal voltage to excitation voltage with the shunt calibration circuit...

Page 52: ...ading VI is in the Data Acquisition Signal Conditioning subpalette The prototypes for the NI DAQ functions Strain_Convert and Strain_Buf_Convert are in the header file convert h for C C and convert ba...

Page 53: ...t 1000 is 0 5 mVout VEX input Note S is left unwired Figure 4 3 Quarter Bridge I Circuit Diagram The following symbols apply to the circuit diagram and equations R1 and R2 are half bridge completion r...

Page 54: ...wiring use the three wire connection shown in Figure 4 3 The wires connected to terminals S and QTR carry the same current and are on opposite sides of the same element of the bridge Therefore any tem...

Page 55: ...ct with the strain specimen but not bonded to the specimen and is usually mounted transverse perpendicular to the principle axis of strain This configuration is often confused with the half bridge typ...

Page 56: ...e dummy gauge element must always be unstrained and mounted to the same type of material as the active gauge but not strained The dummy gauge temperature must closely track the temperature of the acti...

Page 57: ...ding Strain A half bridge type I has the following characteristics Two active strain gauge elements One is mounted in the direction of axial strain the other acts as a Poisson gauge and is mounted tra...

Page 58: ...tion Notes In half bridge type I R4 is mounted along the principal axis of the stress field and R3 is mounted transverse to the axis of the stress field Use this configuration in applications where no...

Page 59: ...ype II Rejecting Axial and Measuring Bending Strain A half bridge type II configuration has the following characteristics Two active strain gauge elements One is mounted in the direction of bending st...

Page 60: ...type II requires one strain gauge to undergo tensile strain while the other strain gauge undergoes compressive strain of the same magnitude This configuration is often used to measure bending strain...

Page 61: ...Full Bridge Type I Rejecting Axial and Measuring Bending Strain A full bridge type I configuration has the following characteristics Four active strain gauge elements Two are mounted in the direction...

Page 62: ...the effect on strain of applying a shunt resistor across R3 use the following equation Notes Strain gauges need not have a particular STC number As shown in Figure 4 11 for greatest calibration accura...

Page 63: ...icular to the principal axis of strain with one on one side of the strain specimen top and the other on the opposite side bottom Rejects axial strain Compensates for temperature Compensates for the ag...

Page 64: ...s and on opposite sides of the beam and R1 and R2 are positioned transverse to the beam axis and on opposite sides of the beam Strain gauges need not have a particular STC number As shown in Figure 4...

Page 65: ...icular to the principal axis of strain with one on one side of the strain specimen top and the other on the opposite side bottom Compensates for temperature Rejects bending strain Compensates for the...

Page 66: ...rain measurement R2 and R4 are positioned along the beam axis and on opposite sides of the beam and R1 and R3 are positioned transverse to the beam axis and on opposite sides of the beam Strain gauges...

Page 67: ...A0 SCB0 SCB0 Shunt Cal A Shunt Cal B Quarter Bridge Completion QTR RS0 SCA0 Screw Terminals to Field Wiring SCXI 1314 Terminal Block SCXI 1520 Module Multiplexer Control Analog Multiplexer To Analog B...

Page 68: ...on circuitry adjusts the signal voltage by a specified offset after an offset null calibration is performed The signal from the instrumentation amplifier stage passes through a lowpass filter stage a...

Page 69: ...CXI 1314 connects across a leg of a Wheatstone bridge For more detailed information about the operation of any of these circuitry stages refer to the Bridge Configuration and Completion section the Ex...

Page 70: ...n of another channel The output buffers have negative feedback connections at the terminal block remote sense terminals RSX and RSX You can run separate wires from the bridge to these terminals so tha...

Page 71: ...the bridge to these terminals so that the amplifiers obtain feedback directly from the bridge forcing bridge voltage to exactly equal the desired setting This removes unwanted DC offset in the signal...

Page 72: ...riate for fully utilizing the range of the digitizing E M Series DAQ device The first gain stage the instrumentation amplifier stage provides gains of either 1 or 20 The second gain stage provides man...

Page 73: ...surement Studio By combining hardware anti aliasing with digital filtering you can choose any cutoff frequency The Advanced Analysis functions are only available in LabVIEW Full or Professional Develo...

Page 74: ...of correction the voltage nulling range for each potentiometer depends on the channel gain setting Table 4 2 summarizes the nulling range and scale of the control codes In most cases you do not expli...

Page 75: ...section of Chapter 3 Configuring and Testing for more information about performing shunt calibration automatically in global channels using NI DAQmx in MAX or strain virtual channels using Traditiona...

Page 76: ...ld Simultaneous sample and hold SS H signal conditioning allows multiplexing MIO DAQ devices to return synchronized samples of all channels with negligible skew time between channels SS H signal condi...

Page 77: ...one module disables this feature for all modules in all chassis that are controlled by the same DAQ device You should only disable SS H if your application does not require simultaneous sampling and...

Page 78: ...holding all the SS H channels and the first A D conversion NoC is number of channels the total number of channels being sampled in the scan list SS H or not MSTMIO is minimum settle time of MIO invers...

Page 79: ...able 4 3 NI DAQmx Values Used to Determine Maximum Sample Rate in Multiplexed Mode MIO Device Device Accuracy Bits Device Max Sample Rate S s HT s NoC MSTMIO s MSTSCXI s TT s Default NI DAQmx SR Multi...

Page 80: ...e in Parallel Mode MIO Device Device Accuracy Bits Device Max Sample Rate S s HT s NoC MSTMIO s TT s Default NI DAQmx SR Parallel Hz DAQmx SR Required for Maximum Accuracy Hz NI 6070E 12 1250000 3 8 0...

Page 81: ...2 bit MIO 1 1000 k 10 s for 16 bit MIO TT is track time the minimum time between the last AD conversion of the current scan and engaging the hold signal of SS H channels of next scan Table 4 5 shows s...

Page 82: ...I module The list can contain channels in any physical order and the multiplexer can sequence the channel selection from the scan list in any order The ordering of scanned channels need not be sequent...

Page 83: ...imum acquisition rate of the system in multiplexed mode operation Theory of Parallel Mode Operation Parallel mode is ideal for high speed acquisitions In parallel mode the eight conditioned analog out...

Page 84: ...is that are controlled by the same DAQ device SS H should only be disabled if your application does not require simultaneous sampling and requires higher acquisition rates than are possible with SS H...

Page 85: ...ask immediately terminates the currently active operation such as a read or a write Aborting a task puts the task into an unstable but recoverable state To recover the task in DAQmx use DAQmx Start to...

Page 86: ...1520 User Manual 5 2 ni com Typical Program Flowchart Figure 5 1 shows a typical program flowchart for creating a task to configure channels take a measurement analyze the data present the data stop...

Page 87: ...in DAQ Assistant or MAX No Hardware Timing Triggering Create Task Using DAQ Assistant No Yes No Yes Configure Channels Further Configure Channels Start Measurement Read Measurement Clear Task Continu...

Page 88: ...ween channels in the same task If you are using an ADE other than an NI ADE or if you want to explicitly create and configure a task for a certain type of acquisition you can programmatically create t...

Page 89: ...or select the active edge of the clock signal Configuring Channel Properties All ADEs used to configure the SCXI 1520 access an underlying set of NI DAQmx properties Table 5 1 shows some of these pro...

Page 90: ...ridge Shunt Cal Shunt Cal Select AI Bridge ShuntCal Select Specifies which calibration switch es to enable Analog Input General Properties Signal Conditioning Excitation Value AI Excit Val Specifies t...

Page 91: ...configuration of the global channel s or programmatically using the DAQmx Offset Null function in LabVIEW use Daqmx Perform Bridge Offset Nulling Analog Input General Properties Signal Conditioning B...

Page 92: ...hannel or Task section of Chapter 3 Configuring and Testing for information about shunt calibration in MAX To manually perform shunt calibration refer to the Shunt Calibration section of Chapter 4 The...

Page 93: ...in another task Note In LabVIEW tasks are automatically cleared Developing an Application Using LabVIEW This section describes in more detail the steps shown in the typical program flowchart in Figure...

Page 94: ...configured the channels using the DAQ Assistant Any channel modifications made with a channel property node are not saved in the task in the DAQ Assistant They are only available for the present sessi...

Page 95: ...e lists of properties with another Active Channels box and assign the appropriate channel to each list of properties Note If you do not use Active Channels the properties are set on all of the channel...

Page 96: ...9 To add another property to the property node right click an existing property and left click Add Element To change the new property left click it and select the property you wish to define Note Ref...

Page 97: ...the type of property node you wish to configure 5 The ActiveChan item allows you to specify what channel s you want to configure If you want to configure several channels with different properties sep...

Page 98: ...ssistant creates the code for the task based on the parameters you define in MAX and the device defaults To change a property of the channel programmatically use the DAQmxSetChanAttribute function Not...

Page 99: ...Double minVal 0 001 System Double maxVal AIStrainGageConfiguration FullBridgeIII AIStrainGageConfiguration strainGageConfiguration AIExcitationSource Internal AIExcitationSource excitationSource 3 3...

Page 100: ...e this list to determine what kind of properties you need to set to configure the device for your application For a complete list of NI DAQmx properties refer to your ADE help file Table 5 3 NI DAQmx...

Page 101: ...dge NomResistance Specifies in ohms the resistance of the bridge in an unloaded condition Analog Input Strain Strain Gage Gage Factor AI StrainGage GageFactor Specifies the sensitivity of the strain g...

Page 102: ...create a task or global channel in unlicensed mode These messages continue to appear until you install version 7 0 or later of an NI ADE This section describes how to configure and use Traditional NI...

Page 103: ...hout additional code When you use virtual channels the maximum number of channels per E Series DAQ device is 512 in multichassis systems NI recommends using the strain virtual channel for ease of use...

Page 104: ...he virtual channels you want to scan in any order or repeatedly in a channel string array Typical Program Flow After you have determined how you want to address the channels and whether you want to co...

Page 105: ...Create Virtual Channel in MAX Use Virtual Channel or SCXI Channel String Perform Shunt Calibration SCXI Channel String Configure Acquisition Settings Configure Mode Properties Perform Offset Null Yes...

Page 106: ...1520 module A setting established through AI Parameter VI is only valid for the LabVIEW session and does not change the setting in MAX You can use the AI Parameter VI to configure the SCXI 1520 setti...

Page 107: ...Shunt A Enabled 25 Boolean In T F TRUE turns switch ON FALSE turns switch OFF Shunt B Enable SCXI Shunt B Enabled 26 Boolean In T F TRUE turns switch ON FALSE turns switch OFF Table 5 4 Settings for...

Page 108: ...bridge sensor If you are measuring strain you can use the strain virtual channel in Traditional NI DAQ Legacy to perform offset null compensation shunt calibration and to properly scale strain measure...

Page 109: ...l returns measurements in units of microstrain rather than the units of interest for the sensor If you require alternative scaling you can either use an analog input voltage virtual channel with a cus...

Page 110: ...rammatically engage and disengage the shunt calibration As with all settings that are controlled by the AI Parameter VI the switch settings take effect when the next AI Start VI is encountered in your...

Page 111: ...Diagram Figure 4 7 Half Bridge Type I Circuit Diagram Figure 4 9 Half Bridge Type II Circuit Diagram Figure 4 11 Full Bridge Type I Circuit Diagram Figure 4 13 Full Bridge Type II Circuit Diagram and...

Page 112: ...alysis functions that you can find in the function subpalettes Analyze Waveform Conditioning and Analyze Signal Processing You can perform post acquisition processing such as waveform comparisons harm...

Page 113: ...ramming with the low level DAQ function calls If you are using LabWindows CVI or Measurement Studio you also can write advanced applications using the same low level DAQ functions guidelines Low Level...

Page 114: ...t Calibration Configure Acquisition Settings Configure Module Settings Perform Offset Null Compensation Perform Acquisition Configure Acquisition Settings Configure Module Settings Engage Shunts Confi...

Page 115: ...tart Programs National Instruments NI DAQ Table 5 5 Configuration Functions Function Description SCXI_Reset Resets the hardware such as the specified module to its default state You also can use SCXI_...

Page 116: ...he NI DAQ function calls shown in Table 5 6 For more information regarding each setting refer to the Traditional NI DAQ Function Reference Help installed by default in Start Programs National Instrume...

Page 117: ...56 65 75 87 100 115 130 150 180 200 220 240 270 310 360 420 560 650 750 870 1000 Bandwidth SCXI_Configure_Filter i16 filterMode filter configuration mode f64 freq filter cutoff frequency if filterMod...

Page 118: ...er performing an offset null compensation you can perform a shunt calibration programmatically This process is described in the Shunt Calibration section of Chapter 4 Theory of Operation You can use S...

Page 119: ...channel so you should demultiplex the data using SCAN_Demux SCAN_Demux rearranges or demultiplexes data acquired by a SCAN_Op into row major order meaning each row of the array holding the data corres...

Page 120: ...se to generate a simple plot of the data Other Application Documentation and Material Refer to the ADE manual and the DAQ analog input examples that come with your application software for more detail...

Page 121: ...de the calibration EEPROM and provide software correction values your application development software uses to correct the measurements for offset errors in the module To obtain the highest level of a...

Page 122: ...d for all gain settings You must repeat the procedure to calibrate other channels in the module Internal Calibration Using a C Based ADE For internal calibration using a C based ADE complete the follo...

Page 123: ...set in the measurement system signal leads with significant lead resistance as well as other system variables can create offset Refer to the Offset Null Compensation section of Chapter 4 Theory of Ope...

Page 124: ...h the following gain settings 1 1 15 1 3 1 5 1 8 2 2 2 2 4 2 7 3 1 3 6 4 2 5 6 6 5 7 5 8 7 10 11 5 13 15 18 20 22 24 27 31 36 42 56 65 75 87 100 115 130 150 180 200 220 240 270 310 360 420 560 650 750...

Page 125: ...0 V 0 03 5 100 0 mV 100 0 0 1 50 0 V 100 0 V 10 0 V 0 03 5 50 0 mV 200 0 0 1 50 0 V 50 0 V 5 0 V 0 03 5 18 0 mV 420 0 0 1 50 0 V 20 0 V 2 0 V 0 03 5 10 0 mV 1000 0 0 1 50 0 V 20 0 V 2 0 V 0 03 5 Abso...

Page 126: ...1 80000 4 1 0 03 8 Half Bridge 2500 1000 0 1 40000 2 0 5 0 03 4 Full Bridge 1250 1000 0 1 20000 1 0 2 0 03 2 Absolute accuracy 15 to 35 C Absolute accuracy is Voltage Reading of Reading Offset Error S...

Page 127: ...gain in multiplexed mode 0 0125 accuracy 3 s 0 006 accuracy 10 s 0 0015 accuracy 20 s Noise RTI gain 200 0 1 to 10 Hz 2 0 Vpp Spot noise RTI gain 200 1000 Hz 16 nV Filter Lowpass filter type 4 pole Bu...

Page 128: ...set Null Compensation Range 4 of excitation voltage 20 000 counts of resolution 80 000 offset null compensation range 4 resolution for quarter bridge GF 2 0 Excitation Type Constant voltage Settings 0...

Page 129: ...leakage 1 nA Switch break down voltage 60 VDC Power Consumption V 18 5 to 25 VDC 170 mA max V 18 5 to 25 VDC 170 mA max 5 V 4 75 to 5 25 VDC 50 mA max 1 Half bridge completion is performed inside the...

Page 130: ...input should remain within 10 V of ground Both inputs should be within 10 V of one another Measurement Category I Channel to channel Either the SX or SX input should remain within 10 V of ground Both...

Page 131: ...A emissions AS NZS CISPR 11 Group 1 Class A emissions FCC 47 CFR Part 15B Class A emissions ICES 001 Class A emissions Note For the standards applied to assess the EMC of this product refer to the Onl...

Page 132: ...page at ni com environment This page contains the environmental regulations and directives with which NI complies as well as other environmental information not included in this document Waste Electr...

Page 133: ...channel string entries configures multiple modules for scanning When the application program runs the channel string is used for programming the channel information into the SCXI system The format of...

Page 134: ...the SCXI channels In a single chassis system the obx specifier is optional and causes the gains on the module and E Series DAQ device to be automatically set to fit the input limits parameter When thi...

Page 135: ...als P and P Internal 1 k resistors connect RS to P and RS to P Calibration Ground Channel String The SCXI 1520 has a special calibration feature that enables LabVIEW to ground the module amplifier inp...

Page 136: ...the Functions Data Acquisition Calibration and Configuration palette to automatically perform a self calibration and modify the scaling constants on the module to adjust for any amplifier offset Refer...

Page 137: ...deleting the module or chassis or No to cancel this action Note Deleting the SCXI chassis deletes all modules in the chassis All configuration information for these modules is also lost The SCXI chas...

Page 138: ...they are loose but do not completely remove the thumbscrews Remove the SCXI 1520 by pulling steadily on both thumbscrews until the module slides completely out Figure C 1 Removing the SCXI 1520 1 Cabl...

Page 139: ...est and verify that my SCXI 1520 is working What should I do now Unfortunately there is always the chance that one or more components in the system are not operating correctly You may have to call or...

Page 140: ...Can I configure the SCXI 1520 for use in parallel mode You can configure the SCXI 1520 for parallel mode using NI DAQmx Refer to Chapter 4 Theory of Operation for more information You cannot configure...

Page 141: ...e scanning Yes Flexible scanning is described in Chapter 3 Configuring and Testing but you cannot use flexible scanning when you are using C and Traditional NI DAQ Legacy When using C you can scan onl...

Page 142: ...more information How do I control the gain excitation voltage filter setting bridge configuration potentiometer settings and shunt calibration switches from LabVIEW The gain of each SCXI 1520 channel...

Page 143: ...should I take into consideration when I take measurements from sensors with external excitation Set the SCXI 1520 internal excitation to the closest value to match the external excitation level If yo...

Page 144: ...og Hardware Triggering using SCXI KnowledgeBase by going to ni com info and using the info code rdahtu For digital triggering use your data acquisition device digital triggering functionality through...

Page 145: ...Symbol Prefix Value p pico 10 12 n nano 10 9 micro 10 6 m milli 10 3 k kilo 103 M mega 106 G giga 109 T tera 1012 Numbers Symbols percent positive of or plus negative of or minus plus or minus less th...

Page 146: ...Digital Converter An electronic device often an integrated circuit that converts an analog voltage to a digital number ADE Application Development Environment such as LabVIEW LabWindows CVI Visual Ba...

Page 147: ...th filter A lowpass filter whose characteristics are optimized for maximum flatness in the passband C C Celsius CE European emissions control standard CFR Code of Federal Regulations CH channel channe...

Page 148: ...Collecting and measuring electrical signals from sensors transducers and test probes or fixtures and processing the measurement data using a computer 2 Collecting and measuring the same kinds of elect...

Page 149: ...a specific hardware device such as an E M Series DAQ device droop rate The rate that a sample and hold circuit in hold mode deviates from the true hold value expressed in millivolts per second E EEPR...

Page 150: ...plified sometimes expressed in decibels gain accuracy A measure of deviation of the gain of an amplifier from the ideal gain gain error See gain accuracy Gauge Factor For a given strain gauge is the f...

Page 151: ...ging it input impedance The measured resistance and capacitance between the input terminals of a circuit input offset current The difference between the bias current flowing out of the input terminals...

Page 152: ...metric prefix for 1 million or 106 when used with units of measure such as volts and hertz 2 mega The prefix for 1 048 576 or 220 when used with B to quantify data or computer memory max maximum micr...

Page 153: ...such as AC power lines motors generators transformers fluorescent lights soldering irons CRT displays computers electrical storms welders radio transmitters and internal sources such as semiconductors...

Page 154: ...consisting of multiple I O lines on a E M Series DAQ device 2 a serial or parallel interface connector on a PC pp peak to peak ppm parts per million psi pounds per square inch PX a negative excitatio...

Page 155: ...io that a system attenuates signals in the stopband with respect to the passband usually defined in decibels per octave RS shunt calibration resistance RS remote sense terminal negative input RS remot...

Page 156: ...number of channels in the input group For example one scan acquires one new sample from every analog input channel in the group scan interval accuracy The minimum interchannel delay needed to achieve...

Page 157: ...ply and control circuitry in the SCXI chassis SLOT0SEL Slot 0 select signal SPICLK serial peripheral interface clock signal spot noise The rms noise voltage or rms noise current in a frequency band 1...

Page 158: ...olts direct current VI Virtual Instrument 1 A combination of hardware and or software elements typically used with a PC that has the functionality of a classic stand alone instrument 2 A LabVIEW softw...

Page 159: ...age applied across two opposing terminals small resistance changes in the elements are easily detected by measuring voltage changes across the remaining two terminals working voltage The highest volta...

Page 160: ...4 27 C based environment configuration questions D 5 internal calibration of SCXI 1520 5 38 common questions D 1 configuration troubleshooting self test verification 1 7 configuration settings excita...

Page 161: ...ation Explorer C 1 from SCXI chassis C 1 internal calibration See calibration L LabVIEW software internal calibration of SCXI 1520 5 37 questions about D 3 M Macintosh operating system D 4 maximum wor...

Page 162: ...ng D 3 regulatory compliance specifications A 8 remote sense 2 9 removing SCXI 1520 from Measurement Automation Explorer C 1 from SCXI chassis C 1 S safety specifications A 8 SCXI chassis connecting S...

Page 163: ...4 13 full bridge configuration II 2 7 4 14 full bridge configuration III 2 8 4 16 half bridge configuration I 2 4 4 9 half bridge configuration II 2 5 4 11 quarter bridge configuration I 2 1 4 4 quart...

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