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Chapter 3

Signal Connections

VXI-SC-1102 User Manual

3-26

©

 National Instruments Corporation

is 

±

11 V. This common-mode input range for either positive or negative 

channel input is the maximum input voltage (relative to CGND) that 
will result in a valid measurement. Each channel includes input 
protection circuitry to withstand the accidental application of voltages 
up to ±42 VAC peak or VDC.

Warning:

Exceeding the input damage level (±42 VAC peak or VDC between input 
channels and chassis ground) can damage the VXI-SC-1102, the VXIbus, 
and the VXI-MIO module. National Instruments is 

NOT

 liable for any 

injuries resulting from such signal connections.

Applying a voltage greater than 

±

42 VAC peak or VDC to the VXI-SC-1102 

is an electrical shock hazard. National Instruments is 

NOT

 liable for any 

damages or injuries resulting from such voltage application.

Note:

Exceeding the differential or common-mode input channel ranges results 
in a distorted signal measurement.

Ground-Referencing Your Signals

Your input signals can be either ground-referenced, as shown in 
Figure 3-2, or floating, as shown in Figure 3-3. Before you connect 
your thermocouple or any other signal, determine whether it is 
floating or ground-referenced. If it is a floating signal, you must 
ground-reference the signal in one of two ways. You can connect the 
negative channel input to chassis ground as shown in Figure 3-3 or you 
can use the clamping resistors on a VXI-TB Series terminal block. The 
VXI-TB Series terminal block may also have a resistor pack for pulling 
up the positive inputs for open-thermocouple detection. Consult the 
terminal block installation guide for details.

Do not ground signals which are already ground-referenced; doing so 
will result in a ground loop, which adversely affects your measurement 
accuracy.

!

Содержание VXI-SC-1000

Страница 1: ...VXI SC 1000...

Страница 2: ...VXI SC 1102 User Manual 32 Channel Multiplexer Amplifier Module February 1997 Edition Part Number 321385A 01 Copyright 1997 National Instruments Corporation All Rights Reserved...

Страница 3: ...mark 45 76 26 00 Finland 09 527 2321 France 01 48 14 24 24 Germany 089 741 31 30 Hong Kong 2645 3186 Israel 03 5734815 Italy 02 413091 Japan 03 5472 2970 Korea 02 596 7456 Mexico 5 520 2635 Netherland...

Страница 4: ...NTAL OR CONSEQUENTIAL DAMAGES EVEN IF ADVISED OF THE POSSIBILITY THEREOF This limitation of the liability of National Instruments will apply regardless of the form of action whether in contract or tor...

Страница 5: ...What You Need to Get Started 1 3 Software Programming Choices 1 3 National Instruments Application Software 1 3 NI DAQ Driver Software 1 4 VXIplug play Instrument Driver 1 5 Optional Equipment 1 6 Un...

Страница 6: ...e Program for Calibration 5 4 Appendix A Specifications Appendix B Customer Communication Glossary Index Figures Figure 1 1 VXI Signal Conditioning System 1 1 Figure 1 2 The Relationship between the P...

Страница 7: ...nts National Instruments Corporation vii VXI SC 1102 User Manual Figure 4 1 VXI SC 1102 Block Diagram 4 1 Figure 5 1 Analog Bus Receptacle Pin Assignment 5 2 Tables Table 3 1 Front Connector Signal De...

Страница 8: ...1 Introduction describes the VXI SC 1102 lists what you need to get started optional software and optional equipment and explains how to unpack the VXI SC 1102 Chapter 2 Installation describes how to...

Страница 9: ...alic text denotes emphasis a cross reference or an introduction to a key concept monospace Denotes text or characters that are to be literally input from the keyboard sections of code programming exam...

Страница 10: ...ench National Instruments driver software includes NI DAQ and VXIplug play instrument drivers After you set up your hardware system use either your application or driver software documentation to help...

Страница 11: ...1102 The VXI SC 1102 is part of the VXI signal conditioning system which consists of a carrier module and one or more VXI signal conditioning submodules or filler panels as shown in Figure 1 1 Figure...

Страница 12: ...as a three pole lowpass filter with a 2 Hz cutoff frequency to reject 60 Hz noise Each channel also has an amplifier with a selectable gain of 1 or 100 You can multiplex the VXI SC 1102 inputs to a si...

Страница 13: ...everal options to choose from when programming your National Instruments VXI DAQ hardware You can use LabVIEW LabWindows CVI ComponentWorks VirtualBench or other application development environments w...

Страница 14: ...puter VirtualBench instruments load and save waveform data to disk in the same forms that can be used in popular spreadsheet programs and word processors Using LabVIEW LabWindows CVI ComponentWorks or...

Страница 15: ...e the NI DAQ device driver and contain high level software functions whose architecture is specified by the VXIplug play Systems Alliance The VXIplug play standards increase interoperability with othe...

Страница 16: ...ped in an antistatic package to prevent electrostatic damage to the submodule Electrostatic discharge can damage several components on the submodule To avoid such damage in handling the submodule take...

Страница 17: ...hapter describes how to install current loop receivers on your VXI SC 1102 and gives information about installing your VXI SC 1102 submodule into the VXI SC 1000 carrier module Refer to Figure 2 1 VXI...

Страница 18: ...Chapter 2 Installation VXI SC 1102 User Manual 2 20 National Instruments Corporation 1 Serial Number 2 Product Name 3 Assembly Number 4 RCLx Pads 3 4 2 1...

Страница 19: ...istors in your submodule make sure that there are no signals connected to your submodule front connector Install the resistors by performing the following steps 1 Follow the instructions in the VXI SC...

Страница 20: ...22 National Instruments Corporation Installing Your Hardware Follow the instructions in the VXI SC 1000 Carrier Module Installation Guide to replace the VXI SC 1102 submodule and to install the assem...

Страница 21: ...SC 1102 submodule via the front connector Caution Static electricity is a major cause of component failure To prevent damage to the electrical components in the module observe antistatic techniques wh...

Страница 22: ...21 22 23 24 25 26 27 28 29 30 31 32 A CH31 CH30 CH29 CH28 CH27 CH26 CH25 CH24 CH23 CH22 CH21 CH20 CH19 CH18 CH17 CH16 CH15 CH14 CH13 CH12 CH11 CH10 CH9 CH8 CH7 CH6 CH5 CH4 CH3 CH2 CH1 CH0 CH31 CH30 CH...

Страница 23: ...nnel is 10 V G where G is the gain selected on the VXI SC 1102 input channel This differential input range is the maximum measurable voltage difference between the positive and negative channel inputs...

Страница 24: ...s or injuries resulting from such voltage application Note Exceeding the differential or common mode input channel ranges results in a distorted signal measurement Ground Referencing Your Signals Your...

Страница 25: ...Chapter 3 Signal Connections National Instruments Corporation 3 27 VXI SC 1102 User Manual Figure 3 2 Ground Referenced Signal Connection Vdiff V CH0 Front Signal Connector CH0 CH1 CH1 VXI SC 1102 cm...

Страница 26: ...A4 are connected within the VXI SC 1102 so the position of the MTEMP DTEMP switch on the VXI TB Series terminal block does not matter The input is overvoltage protected to 15 VDC with the power on an...

Страница 27: ...y functional components of the VXI SC 1102 Figure 4 1 VXI SC 1102 Block Diagram Front Signal Connector CH 0 Gain 0 CH 0 CH 31 CH 31 Lowpass Filter Digital Control Calibration EEPROM Lowpass Filter Low...

Страница 28: ...ntrol circuitry consists of the address handler and the following registers Module ID Configuration Status EEPROM Gain and Channel The address handler controls which register is being addressed The Mo...

Страница 29: ...settled The temperature sensor consists of a thermistor located on a National Instruments VXI terminal block The temperature sensor is for cold junction compensation of thermocouples The CJSENSOR chan...

Страница 30: ...ware to store the calibration data in the EEPROM refer to the VXI SC 1102 Register Level Programmer Manual for a more detailed description of the EEPROM In order to calibrate the VXI SC 1102 you will...

Страница 31: ...nd gain calibration factors of the VXI SC 1102 for a given gain perform the following steps for a two point calibration For two point calibration it is best to use input voltages that correspond to th...

Страница 32: ...the output voltages from volt units to your VXI MIO module binary unit You must take into consideration the polarity of your VXI MIO module its resolution 12 bits or 16 bits and gain For example if y...

Страница 33: ...lowing sample C program will help you calibrate the VXI SC 1102 The calibration constants are stored only in NI DAQ memory The input output voltage pairs read by a DMM must be entered by hand Before t...

Страница 34: ...prompt short ret double value do fputs prompt stdout fflush stdin ret scanf lf value while ret return value void main int vxiChassisID commPath moduleSlot slot of module to calibrate moduleChan short...

Страница 35: ...of the DAQ board controlling the chassis while commPath 0 dummyDAQboard commPath dummyDAQrange MIO_FULL_SCALE dummyDAQgain scale pow 2 0 12 0 dummyDAQgain 10 factor for converting to format of 12 bit...

Страница 36: ...enterFloat Enter VXI SC 1102 input voltage User enters vInput2 vOutput2 enterFloat Enter VXI SC 1102 output voltage User enters vOutput2 binOutput1 vOutput1 scale binOutput2 vOutput2 scale Convert to...

Страница 37: ...ges 100 mV gain 100 or 10 V gain 1 Max working voltage signal common mode Each input should remain within 10 V of CGND Input damage level 42 VAC peak or VDC Inputs protected CH 0 31 CJSENSOR Transfer...

Страница 38: ...ed on 1 G Powered off 10 k Overload 10 k Input bias current 0 5 nA Input offset current 1 0 nA CMRR 50 to 60 Hz either gain 110 dB 0 Hz gain 1 75 dB min 0 Hz gain 100 100 dB min Output range 10 V Outp...

Страница 39: ...Gain 1 20 V C Gain 100 1 V C Gain temperature coefficient 10 ppm C Physical Dimensions 115 by 273 mm 4 54 by 10 75 in I O connector 50 pin male ribbon cable rear connector 96 pin male DIN C front conn...

Страница 40: ...ems does not answer your questions we offer fax and telephone support through our technical support centers which are staffed by applications engineers Electronic Services National Instruments has BBS...

Страница 41: ...urce from which you purchased your software to obtain support Telephone Fax Australia 03 9879 5166 03 9879 6277 Austria 0662 45 79 90 0 0662 45 79 90 19 Belgium 02 757 00 20 02 757 03 11 Canada Ontari...

Страница 42: ..._______________________________________________ _______________________________________________________________________________ National Instruments hardware product model __________ Revision ________...

Страница 43: ...___________________________________ Microprocessor _______________________________________________________________ Clock frequency _______________________________________________________________ Type...

Страница 44: ...___________________________________________________ _______________________________________________________________________________ ____________________________________________________________________...

Страница 45: ...1102 User Manual Glossary Numbers Symbols 5 V 5 volt signal degrees ohms percent plus or minus A AC alternating current A D analog to digital Prefix Meaning Value p pico 10 12 n nano 10 9 micro 10 6 m...

Страница 46: ...us C C Celsius CGND chassis ground signal channel pin or wire lead to which you apply or from which you read the analog or digital signal Analog signals can be single ended or differential For digital...

Страница 47: ...a DAQ board F filtering a type of signal conditioning that allows you to filter unwanted signals from the signal you are trying to measure G G gain the factor by which a signal is amplified sometimes...

Страница 48: ...engage from the backplane due to vibration or shock MB megabytes of memory MIO multifunction I O MSB most significant bit mux multiplexer a switching device with multiple inputs that sequentially conn...

Страница 49: ...ing two dissimilar metals The junction produces a small voltage as a function of the temperature transducer excitation a type of signal conditioning that uses external voltages and currents to excite...

Страница 50: ...volts output low VXIbus VMEbus eXtensions for Instrumentation VXIplug play A group of VXI developers dedicated to making VXI devices as Systems Alliance easy to use as possible primarily by simplifyi...

Страница 51: ...3 4 common mode input signal range 3 4 differential input signal range 3 3 exceeding input levels and ranges warning 3 4 signal terminals 3 3 Channel Register 4 2 CJSENSOR signal cold junction sensor...

Страница 52: ...2 N NI DAQ driver software 1 4 to 1 5 P parts locator diagram 2 2 physical specifications A 3 pins front connector pin assignments figure 3 2 front connector signal descriptions table 3 3 power requir...

Страница 53: ...rcuitry 4 3 analog input channels 4 3 analog output 4 3 block diagram of VXI SC 1102 4 1 digital control circuitry 4 2 functional overview 4 1 to 4 2 VXIbus interface 4 2 U unpacking the VXI SC 1102 1...

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