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Lab-PC-1200/AI User Manual

1. Under the copyright laws this publication may not be reproduced or transmitted in any form electronic or mechanical including photocopying recording storing in an information retrieval system or translating in whole or in part without the prior written consent of National Instruments Corporation CVI LabVIEW NI DAQ SCXI are trademarks of National Instruments Corporation Product and company names listed are trademarks or trade names of their respective companies WARNING REGARDING MEDICAL AND CLINICAL USE OF NATIONAL INSTRUMENTS PRODUCTS National Instruments products are not designed with components and testing intended to ensure a level of reliability suitable for use in treatment and diagnosis of humans Applications of National Instruments products involving medical or clinical treatment can create a potential for accidental injury caused by product failure or by errors on the part of the user or application designer Any use or application of National Instruments products for or involving medical or clinical treatment must be performed by properly trained and qualified medical personnel and all traditional medical safeguards equipment and procedures that are appropriate in the particular situation to prevent serious injury or death should always continue to be used when National Instruments products are being used National Instruments products are NOT intended to be a substitute for any form of established process proc
2. 1 ACHO ACH2 of So Grounded le Signal Sais 7_ ACH6 2 ACH1 e o c _ Measured ommon ACH3 Voltage Mode o 2 So l 4 Noise Ground ale ACHE e Potential cm 4 ACH7 of 8 Co 11 AGND gt o V 1200 Series in DIFF Configuration I O Connector Figure 3 4 Differential Input Connections for Grounded Signal Sources With this type of connection the instrumentation amplifier rejects both the common mode noise in the signal and the ground potential difference between the signal source and the 1200 Series ground shown as V m in Figure 3 4 Lab PC 1200 Al User Manual 3 12 National Instruments Corporation Chapter 3 Signal Connections Differential Connections for Nonreferenced or Floating Signal Sources Figure 3 5 shows how to connect a floating signal source to a 1200 Series board configured for DIFF input Configuration instructions are in the Analog I O Configuration section in Chapter 2 Installation and Configuration 1 ACHO as ACH2 ots So 5 ACH4 Floating t 9 So Signal V ACH6 Source 5 o is So 2 ACH O oi 7 Measured 100 ka 3 NE ACH3 ee Voltage Bias 6 ACH5 Current O so Return ACH7 Paths 100 kag NE ee 11 AGND gt I O Connector V 1200 Series in DIFF Configuration Figure 3 5 Differential I
3. Clock speed MHz RAM MB Display adapter Mouse ___ yes ___no___ Other adapters installed Hard disk capacity MB Brand Instruments used National Instruments hardware product model Revision Configuration National Instruments software product Version Configuration The problem is List any error messages The following steps reproduce the problem 1200 Series Hardware and Software Configuration Form Record the settings and revisions of your hardware and software on the line to the right of each item Complete a new copy of this form each time you revise your software or hardware configuration and use this form as a reference for your current configuration Completing this form accurately before contacting National Instruments for technical support helps our applications engineers answer your questions more efficiently National Instruments Products Serial number Interrupt level DMA channels Base I O address NI DAQ LabVIEW or LabWindows CVI version Other Products Computer make and model Microprocessor Clock frequency or speed Type of video board installed Operating system version Operating system mode Programming language Programming language version Other boards in system Base I O address of other boards DMA channels of other boards Interrupt level of other boards Documentation Comm
4. Lab PC 1200 Al User Manual Glossary E EEPROM EXTCONV EXTTRIG EXTUPDATE ft FIFO FSR FTP G GATB lt 0 2 gt GATE IBF Lab PC 1200 Al User Manual electrically erasable programmable read only memory ROM that can be erased with an electrical signal and reprogrammed external convert signal external trigger signal external update signal farad feet first in first out memory buffer full scale range file transfer protocol counter BO B1 B2 gate signals gate signal hexadecimal hertz input buffer full signal inches G 4 National Instruments Corporation INTR T O lour IRQ ISA LED LSB max MB min MIO mux N A NC NRSE interrupt request signal input output output current interrupt request industry standard architecture light emitting diode least significant bit maximum megabytes of memory minutes multifunction I O Glossary multiplexer a switching device with multiple inputs that connects one of its inputs to its output not applicable not connected nonreferenced single ended mode all measurements are made with respect to a common NRSE measurement system reference but the voltage at this reference can vary with respect to the measurement system ground National Instruments Corporation G 5 Lab PC 1200 Al User Manual Glossary 0 OBF OUTBO OUTB1 OVERFLOW OVERRUN P PA PB PC lt 0 7 gt PC P
5. Maximum data acquisition rates number of samples per second are determined by the ADC conversion period plus the sample and hold acquisition time During multichannel scanning the data acquisition rates are further limited by the input multiplexer and programmable gain amplifier settling times After switching the input multiplexers you must allow the amplifier to settle to the new input signal value to within 12 bit accuracy before you perform an A D conversion or you will not get 12 bit accuracy The settling time is a function of the gain selected 4 10 National Instruments Corporation Chapter 4 Theory of Operation Table 4 1 shows the recommended settling time for each gain setting during multichannel scanning Table 4 2 shows the maximum recommended data acquisition rates for both single channel and multichannel data acquisition For single channel scanning this rate is limited only by the ADC conversion period plus the sample and hold acquisition time specified at 10 us For multichannel data acquisition observing the data acquisition rates in Table 4 2 ensures 12 bit resolution The hardware is capable of multiscanning at higher rates than those listed in Table 4 2 but 12 bit resolution is not guaranteed Table 4 1 Analog Input Recommended Settling Time Versus Gain Gain Settling Time Accuracy 0 024 1 LSB 1 10 us typ 14 us max 2 10 13 us typ 16 us max 20 15 us typ 19 us max 50 27 us typ 3
6. e Dither in Digital Audio by John Vanderkooy and Stanley P Lipshitz Journal of the Audio Engineering Society Vol 35 No 12 December 1987 e Your computer s technical reference manual The following National Instruments manual contains detailed information for the register level programmer e Lab PC 1200 AI Register Level Programmer Manual This manual is available from National Instruments by request If you are using NI DAQ or LabVIEW you should not need the register level programmer manual Using NI DAQ LabVIEW or LabWindows CVI is easier than and as flexible as using the low level programming described in the register level programmer manual Refer to the Software Programming Choices in Chapter 1 Introduction of this manual to learn about your programming options Customer Communication Lab PC 1200 Al User Manual National Instruments wants to receive your comments on our products and manuals We are interested in the applications you develop with our products and we want to help if you have problems with them To make it easy for you to contact us this manual contains comment and configuration forms for you to complete These forms are in Appendix B Customer Communication at the end of this manual xii National Instruments Corporation Introduction This chapter describes the 1200 Series boards lists what you need to get started lists software programming choices and optional equipment and
7. eener 12 bits guaranteed Offset error After calibration cee 0 2 mV max Before calibration 50 mV max Gain error relative to internal reference After calibration 0 01 of reading max Before calibration ee 1 of reading max A 6 National Instruments Corporation Appendix A Specifications Voltage Output Ranges wnitinciehiss mics keneden 0 to 10 V 5 V software selectable Output coupling eee DC Output impedance eee 0 2 Q typ Current drive ennen ereen 2 mA Protection sorrera pr e Short circuit to ground Power on state eneen eeen OV Dynamic Characteristics Settling time to full scale range FSR ee 5 us Stability Offset temperature coefficient 50 uV C Gain temperature coefficient 30 ppm C Explanation of Analog Output Specifications Lab PC 1200 Relative accuracy in a D A system is the same as nonlinearity because no uncertainty is added due to code width Unlike an ADC every digital code in a D A system represents a specific analog value rather than a range of values The relative accuracy of the system is therefore limited to the worst case deviation from the ideal correspondence a straight line except noise If a D A system has been calibrated perfectly the relative accuracy specification reflects its worst case absolute error DNL in a D A system is a measure of deviation of code width from 1 LSB In thi
8. DGND External Update Lab PC 1200 only External control signal to update DAC outputs No Connect Lab PC 1200AI only This pin is not connected 40 EXTCONV DIO DGND External Convert External control signal to time A D conversions DI and drive SCANCLK when you use SCXI DO 41 OUTBO DO DGND Output BO Digital output signal of counter BO 42 GATBO DI DGND Gate BO External control signal for gating counter BO 43 OUTB1 DIO DGND Output B 1 Digital output signal of counter B1 DO External control signal for timing a scan interval DI National Instruments Corporation 3 5 Lab PC 1200 Al User Manual Signal Connections Chapter 3 Signal Connections Table 3 1 Signal Descriptions for 1200 Series 1 0 Connector Pins Continued Pin Signal Name Direction Reference Description 44 GATB1 DI DGND Gate B 1 External control signal for gating counter B1 45 CLKB1 DI DGND Clock B1 External control clock signal for counter B1 46 OUTB2 DO DGND Counter B2 Digital output signal of counter B2 47 GATB2 DI DGND Gate B2 External control signal for gating counter B2 48 CLKB2 DI DGND Clock B2 External control clock signal for counter B2 49 5 V DO DGND 5 Volts This pin is fused for up to 1 A of 4 65 to 5 25 V AI Analog Input AO Analog Output Indicate
9. Theory of Operation With this scheme the data from the ADC is interpreted as a 12 bit two s complement number with a range of 2 048 to 2 047 The output from the ADC is then sign extended to 16 bits causing either a leading 0 or a leading F hex to be added depending on the coding and the sign Thus data values read from the FIFO are 16 bits wide Data Acquisition Operations Lab PC 1200 Al User Manual This manual uses the phrase data acquisition operation to refer to a sequence of timed A D conversions The 1200 Series boards perform data acquisition operations in one of three modes controlled acquisition mode freerun acquisition mode and interval scanning acquisition mode The 1200 Series boards perform both single channel and multichannel scanned data acquisition The data acquisition timing circuitry consists of various clocks and timing signals that control the data acquisition operation data acquisition timing consists of signals that initiate a data acquisition operation time the individual A D conversions gate the data acquisition operation and generate scanning clocks The data acquisition operation can be timed either by the timing circuitry or by externally generated signals These two timing modes are software configurable Data acquisition operations are initiated either externally through EXTTRIG or through software The data acquisition operation is terminated either internally by counter Al of the 82C53 A
10. National Instruments Corporation Chapter 1 Introduction LabVIEW features interactive graphics a state of the art user interface and a powerful graphical programming language The LabVIEW Data Acquisition VI Library a series of VIs for using LabVIEW with National Instruments DAQ hardware is included with LabVIEW The LabVIEW Data Acquisition VI Library is functionally equivalent to the NI DAQ software LabWindows CVI features interactive graphics a state of the art user interface and uses the ANSI standard C programming language The LabWindows CVI Data Acquisition Library a series of functions for using LabWindows CVI with National Instruments DAQ hardware is included with the NI DAQ software kit The LabWindows CVI Data Acquisition library is functionally equivalent to the NI DAQ software Using LabVIEW or LabWindows CVI software will greatly reduce the development time for your data acquisition and control application NI DAQ Driver Software The NI DAQ driver software is included at no charge with all National Instruments DAQ hardware NI DAQ is not packaged with SCXI or accessory products except for the SCXI 1200 NI DAQ has an extensive library of functions that you can call from your application programming environment These functions include routines for analog input A D conversion buffered data acquisition high speed A D conversion analog output D A conversion waveform generation timed D A conversion digital I
11. figure 3 32 mode 2 bidirectional timing figure 3 33 T O connector exceeding maximum ratings warning 3 1 pin assignments Lab PC 1200 figure 3 2 Lab PC 1200AI figure 3 3 L Lab PC 1200 AI block diagram Lab PC 1200 4 1 Lab PC 1200AI 4 2 custom cabling 1 5 optional equipment 1 5 overview 1 1 requirements for getting started 1 1 to 1 2 software programming choices LabVIEW and LabWindows CVI software 1 2 to 1 3 NI DAQ driver software 1 3 to 1 4 register level programming 1 4 unpacking 1 2 LabVIEW and LabWindows CVI software 1 2 to 1 3 Lab PC 1200 Al User Manual Index manual See documentation mode input timing 3 31 mode output timing 3 32 mode 2 bidirectional timing 3 33 multichannel scanned data acquisition 4 10 multiplexers analog input 4 6 NI DAQ driver software 1 3 to 1 4 NRSE input configuration 2 10 definition table 2 9 single ended connections for ground referenced signal sources 3 15 to 3 16 summary of input configurations table 3 10 0 OBF signal description table 3 30 mode 1 output timing figure 3 32 mode 2 bidirectional timing figure 3 33 operation of Lab PC 1200 AI See theory of operation OUT signals general purpose timing signal connections 3 26 to 3 29 timing requirements figure 3 29 OUTBO signal table 3 5 OUTBI signal definition table 3 5 interval scanning data acquisition 3 24 maximum voltage input rating 3 26 OUTB2 signal
12. nennen eneen een 3 22 General Purpose Timing Signal Connections nne 3 26 Timing Specifications csset oieee iresi ee 3 30 Mode 1 Input Timing enen enven ven vennenn eener 3 31 Mode 1 Output Timing nennen ennen neons envennvenvenn 3 32 Mode 2 Bidirectional Timing nennen erneer eenn 3 33 Chapter 4 Theory of Operation Punctronal Overview nesre puetesse enen SE 4 1 PC I O Channel Interface Circuitry nennen enneeneennerneenneeneeenvenveenvenveenven 4 2 PAOD teren tetra T E nnee TA tee Santa pal ee neigen in E 4 3 Analog Input seee a HER Bes ae ee ee ea Ee ata Rd 4 5 Analog Input Cue user y sherekea ipne a aa tedere venen edere 4 6 Data Acquisition Operations nennen ennerseoenvenveenveeneenvenveenvennvenvenn 4 8 Lab PC 1200 Al User Manual vi National Instruments Corporation Contents Controlled Acquisition Mode oenen nne onse eneenven 4 8 Freerun Acquisition Mode annen oneens envennvenvenn 4 9 Interval Scanning Acquisition Mode naeve vennen 4 9 Single Channel Data Acquisition nonnen env eneen 4 10 Multichannel Scanned Data AcquisitiOn nennen 4 10 Data Acq isttton Rates 2 550 sak sorsenvernenveneserennventednetandenrent nee ged atdndnaneaddd a Entel 4 10 Anale Output ereen eee n votes EEE E EE ah os cas echo E EEE E E E E ounces aed 4 12 Analog Output Circuitry siisii irere ieies s Ea EE Er e a Te EE 4 12 DAC Timing Ere senaat e a EE Er eE ee leben EEES oe 4 13 Digital OTT 4 13 Chapter 5
13. 1200 Al User Manual Appendix A Specifications Dither or additive white noise has the effect of forcing quantization noise to become a zero mean random variable rather than a deterministic function of input For more information on the effects of dither see Dither in Digital Audio by John Vanderkooy and Stanley P Lipshitz Journal of the Audio Engineering Society Vol 35 No 12 Dec 1987 Explanation of Data Acquisition Rates Maximum data acquisition rates number of samples per second are determined by the conversion period of the ADC plus the sample and hold acquisition time which is specified at 10 us During multichannel scanning the data acquisition rates are further limited by the settling time of the input multiplexers and programmable gain amplifier After the input multiplexers are switched the amplifier must be allowed to settle to the new input signal value to within 12 bit accuracy The settling time is a function of the gain selected Analog Output Lab PC 1200 Only Lab PC 1200 Al User Manual Output Characteristics Number of channels Two voltage Resolution eneen 12 bits 1 in 4 096 Typical update rate ee 1 kS s system dependent Type of DAC orna uie Double buffered Data transfers eee Interrupts programmed I O Transfer Characteristics Relative accuracy INL 0 25 LSB typ 0 50 LSB max DIN EE E E EE eas cscs 0 25 LSB typ 0 75 LSB max Monotonicity
14. Al User Manual Telephone 03 9879 5166 0662 45 79 90 0 02 757 00 20 011 288 3336 905 785 0085 514 694 8521 45 76 26 00 09 725 725 11 01 48 14 24 24 089 741 31 30 2645 3186 03 6120092 02 413091 03 5472 2970 02 596 7456 5 520 2635 0348 433466 32 84 84 00 2265886 91 640 0085 08 730 49 70 056 200 51 51 02 377 1200 01635 523545 512 795 8248 B 2 Fax 03 9879 6277 0662 45 79 90 19 02 757 03 11 O11 288 8528 905 785 0086 514 694 4399 45 76 26 02 09 725 725 55 01 48 14 24 14 089 714 60 35 2686 8505 03 6120095 02 41309215 03 5472 2977 02 596 7455 5 520 3282 0348 430673 32 84 86 00 2265887 91 640 0533 08 730 43 70 056 200 51 55 02 737 4644 01635 523154 512 794 5678 National Instruments Corporation Technical Support Form Photocopy this form and update it each time you make changes to your software or hardware and use the completed copy of this form as a reference for your current configuration Completing this form accurately before contacting National Instruments for technical support helps our applications engineers answer your questions more efficiently If you are using any National Instruments hardware or software products related to this problem include the configuration forms from their user manuals Include additional pages if necessary Name Company Address Fax Phone Computer brand Model Processor Operating system include version number
15. Calibration Calibration at Higher Gains 0 eee cee eeeeeeeeeeeseeseecaecssecaecaeaecnscseceseseeeeseaeeeeseaes 5 2 Calibration Equipment Requirements eee ee ceceeeceeceeeeeseeeeceseeeeecneeeaeeaeecaecnaeeaees 5 2 Using the Calibration Function nonnen envennvenvennennvennenneeneersverneenvennvenven 5 3 Appendix A Specifications Appendix B Customer Communication Glossary Index Figures Figure 1 1 The Relationship between the Programming Environment NI DAQ and Your Hardware saneren neen vennvevenenssever venen 1 4 Figure 3 1 Lab PC 1200 I O Connector Pin Assignment eenen 3 2 Figure 3 2 Lab PC 1200AI I O Connector Pin Assignments en 3 3 Figure 3 3 1200 Series Instrumentation Amplifier eenen ennen 3 8 Figure 3 4 Differential Input Connections for Grounded Signal Sources 3 12 Figure 3 5 Differential Input Connections for Floating Sources eee 3 13 Figure 3 6 Single Ended Input Connections for Floating Signal Sources 3 15 Figure 3 7 Single Ended Input Connections for Grounded Signal Sources 3 16 Figure 3 8 Analog Output Signal Connections annen ennernvenneenvervenn 3 18 National Instruments Corporation vii Lab PC 1200 Al User Manual Contents Figure 3 9 Digital I O Connections ann ennereene verven veenvenvennvenveneerne 3 20 Figure 3 10 EXTCONV Signal Timing enn annernvennvenvenveenvenvennvenveneerne 3 22 Figure 3 11 Posttrigge
16. Group B Counter OUTAO 1 O Connector OUTB1 CLKA1 EXTCONV Sample Counter A D Conversion Logic GATEA1 keel i i OUTA1 Lab PC 1200 Only __ _EXTTRIG CLKA2 sy GATEA2 AMT i i i DAC EXTUPDATE i i i Timing OUTA2 D A Conversion Logic 82C53 Counter Timer Group A Figure 4 4 1200 Series Timing Circuitry Lab PC 1200 Al User Manual 4 4 National Instruments Corporation Chapter 4 Theory of Operation Each 82C53 contains three independent 16 bit counter timers and one 8 bit mode register Each counter has a CLK input pin a GATE input pin and an OUT output pin You can program all six counter timers to operate in several useful timing modes The first group of counter timers is group A and includes AO Al and A2 For internal data acquisition timing on both boards you can use counters AO and Al If you have a Lab PC 1200 you can also use counter A2 for analog output timing Or instead of using these three counters you can use the three external timing signals EXTCONV EXTTRIG and EXTUPDATE for data acquisition and DAC timing For external data acquisition timing on both boards you can use the EXTCONV and EXTRIG signals If you have a Lab PC 1200 you can also use the EXTUPDATE signal for analog output timing The second group of counter timers is group B and includes BO B1 and B2
17. In no event shall National Instruments be liable for any damages arising out of or related to this document or the information contained in it EXCEPT AS SPECIFIED HEREIN NATIONAL INSTRUMENTS MAKES NO WARRANTIES EXPRESS OR IMPLIED AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE CUSTOMER S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA PROFITS USE OF PRODUCTS OR INCIDENTAL 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 tort including negligence Any action against National Instruments must be brought within one year after the cause of action accrues National Instruments shall not be liable for any delay in performance due to causes beyond its reasonable control The warranty provided herein does not cover damages defects malfunctions or service failures caused by owner s failure to follow the National Instruments installation operation or maintenance instructions owner s modification of the product owner s abuse misuse or negligent acts and power failure or surges fire flood accident actions of third parties or other events outside reasonable control
18. Instrumentation Amplifier Vint OF Vm Measured Voltage Vin Vint Vin GAIN Figure 3 3 1200 Series Instrumentation Amplifier The instrumentation amplifier applies gain common mode voltage rejection and high input impedance to the analog input signals connected to the 1200 Series board Signals are routed to the positive and negative inputs of the instrumentation amplifier through input multiplexers on the board The instrumentation amplifier converts two input signals to a signal that is the difference between the two input signals multiplied by the gain setting of the amplifier The amplifier output voltage is referenced to the board ground The 1200 Series ADC measures this output voltage when it performs A D conversions 3 8 National Instruments Corporation Chapter 3 Signal Connections All signals must be referenced to ground either at the source device or at the 1200 Series board If you have a floating source you must use a ground referenced input connection at the board If you have a grounded source you must use a nonreferenced input connection at the board Types of Signal Sources When configuring the input mode of the 1200 Series and making signal connections first determine whether the signal source is floating or ground referenced These two types of signals are described in the following sections Floating Signal Sources A floating signal source does not connect in any way to earth g
19. Lab PC 1200 AI recommended in switchless mode 278 to 28F AT Parallel Printer Port 2 LPT2 279 Reserved for Plug and Play operation 280 to 29F WD EtherCard default 2A0 to 2BF Unreserved 2E2 to 2F7 Unreserved 2F8 to 2FF PC AT Serial Port 2 COM2 300 to 30F 3Com EtherLink default 310 to 31F Unreserved 320 to 32F ICM PC XT Fixed Disk Controller 330 to 35F Unreserved 360 to 363 PC Network low address 364 to 367 Reserved 368 to 36B PC Network high address 36C to 36F Reserved 378 to 37F PC AT Parallel Printer Port 1 LPT1 2 4 National Instruments Corporation Chapter 2 Installation and Configuration Table 2 1 PC AT I O Address Map Continued I O Address Range Hex Device 380 to 38C SDLC Communications 380 to 389 Bisynchronous BSC Communications alternate 390 to 393 Cluster Adapter 0 394 to 39F Unreserved 3A0 to 3A9 BSC Communications primary 3AA to 3AF Unreserved 3B0 to 3BF Monochrome Display Parallel Printer Adapter 0 3C0 to 3CF Enhanced Graphics Adapter VGA 3D0 to 3DF Color Graphics Monitor Adapter VGA 3E0 to 3EF Unreserved 3F0 to 3F7 Diskette Controller 3F8 to 3FF Serial Port 1 COM1 A79 Reserved for Plug and Play operation National Instruments Corporation 2 5 Lab PC 1200 Al User Manual Chapter 2 Installation and Configuration Table 2 2 PC AT Interrupt Assignment Map IRQ Device 15 Available 14 Fixed Dis
20. MHz a Oscillator gt Divider Timebase The The Figure 4 2 Lab PC 1200Al Block Diagram major components of the 1200 Series boards are as follows PC I O interface circuitry Timing circuitry Analog input circuitry Digital I O circuitry Calibration circuitry Lab PC 1200 also contains an analog output circuitry component The internal data and control buses interconnect the components The rest of the chapter explains the theory of operation of each of the 1200 Series components Calibration circuitry is discussed in Chapter 5 Calibration PC 1 0 Channel Interface Circuitry Lab PC 1200 Al User Manual The PC I O channel consists of an address bus a data bus a DMA arbitration bus interrupt lines and several control and support signals The components making up the 1200 Series boards interface circuitry are shown in Figure 4 3 4 2 National Instruments Corporation Chapter 4 Theory of Operation Address Bus Control Lines PC I O Channel DMA REQ DMAACK Address Latches gt Address p Register Selects Timing Interface Decoder Data Buffers B Read and Write amp Internal Data Bus DMA Control DMA Request pb DMA ACK and DMATC Interrupt Control Interrupt Requests Figure 4 3 PC Interface Circuitry The 1200 Se
21. O counter timer operations SCXI RTSI self calibration messaging and acquiring data to memory NI DAQ has both high level DAQ I O functions for maximum ease of use and low level DAQ I O functions for maximum flexibility and performance Examples of high level functions are streaming data to disk or acquiring a certain number of data points An example of a low level function is writing directly to registers on the DAQ device NI DAQ does not sacrifice the performance of National Instruments DAQ devices because it lets multiple devices operate at their peak performance NI DAQ also internally addresses many of the complex issues between the computer and the DAQ hardware such as programming interrupts and DMA controllers NI DAQ maintains a consistent software interface among its different versions so that you can change platforms with minimal modifications to your code Whether you are using conventional programming languages LabVIEW or LabWindows CVI your application uses the NI DAQ driver software as illustrated in Figure 1 1 National Instruments Corporation 1 3 Lab PC 1200 Al User Manual Chapter 1 Introduction ComponentWorks Conventional LabVIEW Programming Environment LabWindows CVI or VirtualBench NI DAQ Driver Software Personal eis ve En ad Computer or araware Workstation Figure 1 1 The Relationship between the Programming Environment NI DAQ a
22. PC 1200 only Voltage output signal for analog output channel 0 NC No Connect Lab PC 1200AI only This pin is a low impedance to ground 11 AGND N A N A Analog Ground Analog output ground reference for analog output voltages Bias current return point for differential measurements 12 DACIOUT AO AGND Digital to Analog Converter 1 Output Lab PC 1200 only Voltage output signal for analog output channel 1 NC No Connect Lab PC 1200AI only This pin is a low impedance to ground Lab PC 1200 Al User Manual 3 4 National Instruments Corporation Chapter 3 Table 3 1 Signal Descriptions for 1200 Series 1 0 Connector Pins Continued Pin Signal Name Direction Reference Description 13 50 DGND N A N A Digital Ground Voltage ground reference for the digital signals and the 5 V supply 14 21 PA lt 0 7 gt DIO DGND Port A 0 through 7 Bidirectional data lines for port A PA7 is the MSB and PAO is the LSB 22 29 PB lt 0 7 gt DIO DGND Port B 0 through 7 Bidirectional data lines for port B PB7 is the MSB and PBO is the LSB 30 37 PC lt 0 7 gt DIO DGND Port C 0 through 7 Bidirectional data lines for port C PC7 is the MSB and PCO is the LSB 38 EXTTRIG DI DGND External Trigger External control signal to trigger a data acquisition operation 39 EXTUPDATE NC DI
23. Play system arbitrates and assigns resources through software freeing you from manually setting switches and jumpers These resources include the board base I O address DMA channel and interrupt channel The 1200 Series boards are configured at the factory to request these resources from the Plug and Play Configuration Manager If you have the Windows 98 NT operating system on your computer it will configure your 1200 Series board Refer to your NI DAQ documentation for more information 2 2 National Instruments Corporation Chapter 2 Installation and Configuration Switchless Mode You can use your 1200 Series board in a non Plug and Play system as a switchless DAQ board A non Plug and Play system is a system in which the Configuration Manager has not been installed and which does not contain any non National Instruments Plug and Play products You use the NI DAQ Configuration Utility to enter the base address DMA channel and interrupt channel selections and the application software assigns it to the board i Note To avoid resource conflicts with non National Instruments boards do not configure two boards for the same base address Base 1 0 Address Selection You can configure your 1200 Series board to use base addresses in the range of 100 to 3E0 hex The 1200 Series boards occupy 32 bytes of address space and must be located on a 32 byte boundary Therefore valid addresses include 100 120 140 3CO 3E0 hex This s
24. Windows LabWindows CVI for Windows NI DAQ for PC compatibles 0 Your computer Your 1200 Series board is shipped in an antistatic package to prevent electrostatic damage to the board Electrostatic discharge can damage several components on the board To avoid such damage in handling the board take the following precautions e Ground yourself via a grounding strap or by holding a grounded object e Touch the antistatic package to a metal part of your computer chassis before removing the board from the package e Remove the board from the package and inspect the board for loose components or any other sign of damage Notify National Instruments if the board appears damaged in any way Do not install a damaged board into your computer Never touch the exposed pins of connectors Software Programming Choices There are several options to choose from when programming your National Instruments DAQ and SCXI hardware You can use LabVIEW LabWindows CVI NI DAQ or register level programming LabVIEW and LabWindows CVI Application Software Lab PC 1200 Al User Manual LabVIEW and LabWindows CVI are innovative program development software packages for data acquisition and control applications LabVIEW uses graphical programming whereas LabWindows CVI enhances traditional programming languages Both packages include extensive libraries for data acquisition instrument control data analysis and graphical data presentation 1 2
25. You can use counters BO and B1 for internal data acquisition timing or you can use the external timing signal CLKB1 for analog input timing If you have a Lab PC 1200 you can also use counter BO for analog output timing If you are not using counters BO and B1 for internal timing you can use these counters as general purpose counter timers Counter B2 is reserved for external use as a general purpose counter timer For a more detailed description of counter group A and counters BO and B1 refer to the Analog Input and Analog Output sections Analog Input The 1200 Series boards have eight channels of analog input with software programmable gain and 12 bit A D conversion The 1200 Series boards also contain data acquisition timing circuitry for automatic timing of multiple A D conversions and include advanced options such as external triggering gating and clocking Figure 4 5 shows an analog input circuitry block diagram National Instruments Corporation 4 5 Lab PC 1200 Al User Manual Chapter 4 Theory of Operation ACHO ACH1 ACH2 ACH3 ACH4 ACH5 ACH6 ACH7 ACH1 ACH3 ACHS ACH7 AISENSE AIGND EXTTRIG OUTB1 O Connector Address Address e 8 lt j A D Data 17 Pro Data A D q Data Data Al L lt I FIFO grammable ADC 12 8 Gain Amp AD Digital Control 8 i RD Con
26. between the two codes and the noise is very near 0 5 LSB If the mean is near the center of a code and the noise is relatively small very little or no flicker is seen and the noise is reported by the ADC as nearly 0 LSB From the relationship between the mean of the noise and the measured rms magnitude of the noise the character of the noise can be determined National Instruments has determined that the character of the noise in the 1200 Series boards is fairly Gaussian so the noise specifications given are the amounts of pure Gaussian noise required to produce our readings Explanation of Dither The dither circuitry when enabled adds approximately 0 5 LSB rms of white Gaussian noise to the signal to be converted to the ADC This addition is useful for applications involving averaging to increase the resolution of the 1200 Series to more than 12 bits as in calibration In such applications which are often lower frequency in nature noise modulation is decreased and differential linearity is improved by the addition of dither For high speed 12 bit applications not involving averaging dither should be disabled because it only adds noise When taking DC measurements such as when calibrating the board enable dither and average about 1 000 points to take a single reading This process removes the effects of 12 bit quantization and reduces measurement noise resulting in improved resolution National Instruments Corporation A 5 Lab PC
27. conversion occurs on the next falling edge of EXTCONV Further transitions on the EXTTRIG line have no effect until a new data acquisition sequence is established Lab PC 1200 Al User Manual 3 22 National Instruments Corporation Chapter 3 Signal Connections Figure 3 11 shows a possible controlled data acquisition sequence using EXTCONV and EXTTRIG The rising edge of EXTCONV that enables external conversions must occur a minimum of 50 ns after the rising edge of EXTTRIG The first conversion occurs on the next falling edge of EXTCONV tn ee tm 50 ns min EXTTRIG Cu tg 50 ns min Vi rcon A AAA CONVERT t i Figure 3 11 Posttrigger Data Acquisition Timing In the PRETRIG mode EXTTRIG serves as a pretrigger signal Data is acquired both before and after the EXTTRIG signal occurs A D conversions are software enabled which initiates the data acquisition operation However the sample counter is not started until a rising edge is sensed on the EXTTRIG input Conversions remain enabled until the sample counter counts to zero The maximum number of samples acquired after the stop trigger is limited to 65 535 The number of samples acquired before the trigger is limited only by the size of the memory buffer available for data acquisition Figure 3 12 shows a pretrigger data acquisition timing sequence using EXTTRIG and EXTCONV The data acquisition operation has been initiated through softwa
28. customer communication xii B 1 to B 2 National Instruments Corporation D DAC timing 4 13 DACOOUT signal table 3 4 DACIOUT signal table 3 4 DACWRT signal 3 25 data acquisition and general purpose timing signal connections data acquisition timing connections 3 22 to 3 26 general purpose timing connections 3 26 to 3 29 pins 3 21 power connections 3 21 timing specifications 3 30 to 3 33 mode input timing 3 31 mode 1 output timing 3 32 mode 2 bidirectional timing 3 33 data acquisition operations 4 8 to 4 10 controlled acquisition mode 4 8 to 4 9 freerun acquisition mode 4 9 interval scanning acquisition mode 4 9 multichannel scanned data acquisition 4 10 single channel data acquisition 4 10 data acquisition rates analog input settling time versus gain table 4 11 maximum recommended rates table 4 11 theory of operation 4 10 to 4 11 A 6 data acquisition timing connections See also general purpose timing signal connections EXTCONV signal 3 22 to 3 24 EXTCONV signal timing figure 3 22 EXTTRIG signal 3 22 to 3 24 EXTUPDATE signal 3 25 to 3 26 interval scanning 3 24 to 3 25 Lab PC 1200 3 25 signal timing figure 3 25 pins 3 21 National Instruments Corporation 1 3 Index posttrigger and pretrigger modes 3 22 to 3 24 posttrigger timing figure 3 23 pretrigger timing figure 3 24 sample counter 3 22 sample interval counter 3 22 waveform generation timing sequence 3 2
29. maximum input voltage ratings caution 3 7 floating signal sources 3 9 ground referenced signal sources 3 9 input configurations 3 10 to 3 17 input ranges and maximum ratings 3 7 instrumentation amplifier 3 8 to 3 9 pins 3 6 single ended connections floating signal sources RSE configuration 3 14 to 3 15 grounded signal sources NRSE configuration 3 15 to 3 16 summary of input configurations table 3 10 types of signal sources 3 9 analog output signal connections 3 17 to 3 18 data acquisition and general purpose timing signal connections data acquisition timing connections 3 22 to 3 26 general purpose timing connections 3 26 to 3 29 pins 3 21 National Instruments Corporation Index power connections 3 21 digital I O signal connections illustration 3 20 logical input and output 3 19 to 3 20 pins 3 18 Port C pin connections 3 20 to 3 21 timing specifications 3 30 to 3 33 mode input timing 3 31 mode 1 output timing 3 32 mode 2 bidirectional timing 3 33 T O connector exceeding maximum ratings warning 3 1 pin assignments Lab PC 1200 figure 3 2 Lab PC 1200AI figure 3 3 signal descriptions table 3 4 to 3 6 signal sources See floating signal sources ground referenced signal sources single channel data acquisition 4 10 single ended connections floating signal sources RSE configuration 3 14 to 3 15 ground referenced signal sources NRSE configuration 3 15 to 3 16 purpose a
30. numbered channel to channel 0 and repeats the process Thus you can scan any number of channels from two to eight Notice that you use the same gain setting for all channels in the scan sequence 4 6 National Instruments Corporation Chapter 4 Theory of Operation The programmable gain amplifier applies gain to the input signal allowing an analog input signal to be amplified before being sampled and converted thus increasing measurement resolution and accuracy The instrumentation amplifier gain is software selectable The 1200 Series boards provide gains of 1 2 5 10 20 50 and 100 The dither circuitry when enabled adds approximately 0 5 LSB rms of white Gaussian noise to the signal to be converted to the ADC This addition is useful for applications involving averaging to increase the resolution of the 1200 Series to more than 12 bits as in calibration In such applications which are often lower frequency noise modulation decreases and differential linearity improves by adding dither For high speed 12 bit applications not involving averaging you should disable dither because it only adds noise When taking DC measurements such as when calibrating the board enable dither and average about 1 000 points to take a single reading This process removes the effects of 12 bit quantization and reduces measurement noise resulting in improved resolution Dither or additive white noise has the effect of forcing quantization noise t
31. specifications A 9 bus related configuration base I O address selection 2 3 DMA channel selection 2 3 interrupt channel selection 2 3 to 2 6 PC AT interrupt assignment map table 2 6 PC AT I O address map table 2 4 to 2 5 Plug and Play mode 2 2 switchless mode 2 3 C cabling custom 1 5 Calibrate _1200 function 5 3 calibration calibration DACs 5 1 EEPROM storage 5 2 equipment requirements 5 2 to 5 3 higher gains 5 2 methods 5 1 Lab PC 1200 Al User Manual l 2 overview 5 1 to 5 2 using the Calibrate_1200 function 5 3 circuitry See theory of operation CLK signals general purpose timing signal connections 3 26 to 3 29 timing requirements figure 3 29 CLKB 1 signal table 3 6 CLKB2 signal table 3 6 CNTINT signal 3 25 common mode signal rejection considerations 3 16 to 3 17 configuration See also input configurations analog input modes DIFF 2 10 NRSE 2 10 RSE 2 9 summary table 2 9 analog input polarity 2 8 analog I O 2 7 to 2 8 Lab PC 1200 2 7 Lab PC 1200AI 2 7 to 2 8 analog output polarity 2 8 bus related base I O address selection 2 3 DMA channel selection 2 3 interrupt channel selection 2 3 to 2 6 PC AT interrupt assignment map table 2 6 PC AT I O address map table 2 4 to 2 5 Plug and Play mode 2 2 switchless mode 2 3 controlled acquisition mode 4 8 to 4 9 Counter 0 on 82C53 A counter timer 3 22 Counter 1 on 82C53 A counter timer 3 22 custom cabling 1 5
32. the counter GATE input to start the counter Program the counter to start counting after receiving a low to high edge The time lapse since receiving the edge equals the counter value difference loaded value minus read value multiplied by the CLK period To perform frequency measurement program a counter to be level gated and count the number of falling edges in a signal applied to a CLK input The gate signal applied to the counter GATE input is of known duration In this case program the counter to count falling edges at the CLK input while the gate is applied National Instruments Corporation 3 27 Lab PC 1200 Al User Manual Chapter 3 Signal Connections The frequency of the input signal then equals the count value divided by the gate period Figure 3 16 shows the connections for a frequency measurement application You can also use a second counter to generate the gate signal in this application If you use a second counter however you must externally invert the signal 5V 100 kQ O CLK OUT C TOA GATE Signal Gate Counter Source Source o nn 13 DGND I O Connector 1200 Series Figure 3 16 Frequency Measurement Application The GATE CLK and OUT signals for counters B1 and B2 are available at the I O connector The GATE and CLK pins are internally pulled up to 5 V through a 100 kQ resistor Refer to Appendix A Specific
33. the signals to the 1200 Series board are less than 10 ft e All input signals share a common reference signal at the source If any of the preceding criteria is not met use the DIFF input configuration You can software configure the 1200 Series boards for two different types of single ended connections RSE configuration and NRSE configuration Use the RSE configuration for floating signal sources in this case the 1200 Series boards provide the reference ground point for the external signal Use the NRSE configuration for ground referenced signal sources in this case the external signal supplies its own reference ground point and the 1200 Series boards should not supply one 3 14 National Instruments Corporation Chapter 3 Signal Connections Single Ended Connections for Floating Signal Sources RSE Configuration Figure 3 6 shows how to connect a floating signal source to a 1200 Series board configured for RSE mode Configure the 1200 Series analog input circuitry for RSE input to make these types of connections Configuration instructions are in the Analog I O Configuration section of Chapter 2 Installation and Configuration Floating Signal Source 1 ACHO OO 2 ACHI O 60 9 3 ACH ACH7 ol so 9 AISENSE AIGND 7 Measured el ie l O Connector V ik Voltage AGND MM MV 1200 Series in RSE Configuration Natio
34. 2 0 02 of reading max 2 of reading max National Instruments Corporation Amplifier Characteristics Input impedance Normal powered on Powered off ee Overload annen Input bias current nee Input offset current ene Dynamic Characteristics Bandwidth Appendix A Specifications 100 GO in parallel with 50 pF 4 7 kQ min 4 7 kQ min 100 pA 100 pA 70 dB DC to 60 Hz Small signal 3 dB Settling time for full scale step Gain Bandwidth 1 10 250 kHz 20 150 kHz 50 60 kHz 100 30 kHz Gain Settling Time Accuracy 0 024 1 LSB 1 10 us typ 14 us max 2 10 13 us typ 16 us max 20 15 us typ 19 us max 50 27 us typ 34 us max 100 60 us typ 80 us max National Instruments Corporation A 3 Lab PC 1200 Al User Manual Appendix A Specifications Stability System noise Gain Dither off Dither on including quantization error 1 50 0 3 LSB rms 0 5 LSB rms 100 0 5 LSB rms 0 7 LSB rms Recommended warm up time 15 minutes Offset temperature coefficient PRE SAIN severmorsevanerermtenvns erevetenniien 15 uV C Postga esn onstervereennvantendeeeeiee ne 100 uV C Gain temperature coefficient 40 ppm C Explanation of Analog Input Specifications Lab PC 1200 Al User Manual Relative accuracy is a meas
35. 2 PC AT Interrupt Assignment Map nennen en venneenvennenn 2 6 Table 2 3 Analog I O Settings Lab PC 1200 ennen eneen 2 7 Table 2 4 Analog Input Settings Lab PC 1200AT ene 2 8 Table 2 5 Analog Input Modes for the 1200 Series Boards tees eee 2 9 Table 3 1 Signal Descriptions for 1200 Series I O Connector Pins 3 4 Table 3 2 Bipolar Analog Input Signal Range Versus Gain eee eee 3 7 Table 3 3 Unipolar Analog Input Signal Range Versus Gau sentent teneerste edere 3 7 Table 3 4 Summary of Analog Input Connections ennen 3 10 Table 3 5 Port C Signal Assignments annen ennereoeneene a 3 21 Table 3 6 Port C Signal Descriptions aaneen oneeeve reverse erven veenvenvennvenn 3 30 Table 4 1 Analog Input Recommended Settling Time Versus Gain 4 11 Table 4 2 1200 Series Maximum Recommended Data Acquisition Rates 4 11 Lab PC 1200 Al User Manual viii National Instruments Corporation About This Manual This manual describes the electrical and mechanical aspects of the 1200 Series boards and contains information concerning their operation and programming The Lab PC 1200 and Lab PC 1200AI boards are low cost analog digital and timing boards designed for use in PC AT series computers Additionally the Lab PC 1200 has analog output capabilities These boards are designed for high performance data acquisition DAQ and control for applicatio
36. 200 Series Complex switch circuitry is not shown in order to simplify the figure Lab PC 1200 Al User Manual Figure 3 9 Digital I O Connections In Figure 3 9 port A is configured for digital output and ports B and C are configured for digital input Digital input applications include receiving TTL signals and sensing external device states such as the switch in Figure 3 9 Digital output applications include sending TTL signals and driving external devices such as the LED shown in Figure 3 9 Port C Pin Connections The signals assigned to port C depend on the mode in which the 82C55A is programmed In mode 0 port C is considered to be two 4 bit I O ports In modes 1 and 2 port C is used for status and handshaking signals with two or three I O bits mixed in Table 3 5 summarizes the signal assignments of port C for each programmable mode 3 20 National Instruments Corporation Chapter 3 Signal Connections Table 3 5 Port C Signal Assignments Programmable Group A Group B Mode PC7 PC6 PC5 PC4 PC3 PC2 PCI PCO Mode 0 1 0 1 0 1 0 1 0 1 0 VO VO VO Mode 1 Input O 1 0 IBFa STBa INTRA STBp IBFBB INTRg Mode 1 Output OBF ACK4 1 0 1 0 INTR ACKp OBFg INTRg A Mode 2 OBF ACKy IBFa STBA INTRA VO VO VO Indicates that the signal is active low Power Connections Pin 49 of the I O connector supplies 5 V from th
37. 4 us max 100 60 us typ 80 us max Table 4 2 1200 Series Maximum Recommended Data Acquisition Rates Acquisition Mode Gain Rate Single channel 1 2 5 10 20 50 100 100 kS s Multichannel 1 90 kS s 2 5 10 77 kS s 20 66 6 kS s 50 37 kS s 100 16 6 kS s The recommended data acquisition rates in Table 4 2 assume that voltage levels on all the channels included in the scan sequence are within range for the given gain and are driven by low impedance sources National Instruments Corporation 4 11 Lab PC 1200 Al User Manual Chapter 4 Theory of Operation Analog Output Lab PC 1200 The Lab PC 1200 has two channels of 12 bit D A output Each analog output channel can provide unipolar or bipolar output The Lab PC 1200 also contains timing circuitry for waveform generation timed either externally or internally Figure 4 6 shows the analog output circuitry Two s Complement Address Address DACOWRT 7 gt A gt Data DACOOUT Data Data 8 z Isa Digital eos 5 8 he 8 Control 10 V Internal V 2 9 Control P contro Se counter Reference External Upaate 5 exruppaTe 4 5 Lp a Interrupt Interrupt DAC1WRT gt DAC1OUT 4 1 Two s Complement gt Figure 4 6 Lab PC 1200 Analog Output Circuitry Analog Output Circuitry Lab PC 1200 Al User Manual Each analog output channel conta
38. 5 to 3 26 data acquisition related configuration See configuration DATA signal description table 3 30 mode input timing figure 3 31 mode 1 output timing figure 3 32 mode 2 bidirectional timing figure 3 33 DGND signal table 3 5 DIFF input configuration 2 10 definition table 2 9 summary of input configurations table 3 10 differential connections 3 11 to 3 13 DIFF configuration 3 11 floating signal sources 3 12 to 3 13 ground referenced signal sources 3 11 to 3 12 purpose and use 3 11 differential nonlinearity analog input A 5 analog output A 7 digital I O circuitry 4 13 specifications A 8 digital I O signal connections illustration 3 20 logical input and output 3 19 to 3 20 pins 3 18 Port C pin connections 3 20 to 3 21 digital trigger specifications A 9 dither circuitry 4 7 A 5 to A 6 DMA channel selection 2 3 Lab PC 1200 Al User Manual Index documentation conventions used in manual x National Instruments documentation xi organization of manual ix related documentation xii E electronic support services B 1 to B 2 e mail support B 2 environment specifications A 10 equipment optional 1 5 event counting with external switch gating figure 3 27 general purpose timing signal connections 3 26 EXTCONV signal definition table 3 5 interval scanning data acquisition 3 24 to 3 25 maximum voltage input rating 3 26 posttrigger and pretrigger data acquisition 3 22 t
39. 7 National Instruments Corporation specifications and ratings of 82C53 I O signals 3 28 to 3 29 square wave generation 3 26 time lapse measurement 3 27 timing requirements for GATE CLK and OUT signals figure 3 29 ground referenced signal sources differential connections 3 11 to 3 12 purpose and use 3 9 single ended connections NRSE configuration 3 15 to 3 16 summary of input configurations table 3 10 H hardware configuration See configuration hardware installation 2 1 to 2 2 IBF signal description table 3 30 mode input timing figure 3 31 mode 2 bidirectional timing figure 3 33 input configurations differential connection considerations 3 11 floating signal sources differential connections 3 12 to 3 13 summary of input configurations table 3 10 ground referenced signal sources differential connections 3 11 to 3 12 summary of input configurations table 3 10 installation See also configuration hardware 2 1 to 2 2 software 2 1 unpacking the Lab PC 1200 AI 1 2 instrumentation amplifier 3 8 to 3 9 National Instruments Corporation l 5 Index integral nonlinearity A 4 interrupt channel selection 2 3 to 2 6 PC AT interrupt assignment map table 2 6 PC AT I O address map table 2 4 to 2 5 interval scanning data acquisition description 3 24 theory of operation 4 9 INTR signal description table 3 30 mode input timing figure 3 31 mode output timing
40. 7 gt for digital T O port A Pins 22 through 29 are connected to the digital lines PB lt 0 7 gt for digital I O port B Pins 30 through 37 are connected to the digital lines PC lt 0 7 gt for digital I O port C Pin 13 DGND is the digital ground pin for all three digital I O ports Refer to Appendix A Specifications for signal voltage and current specifications The logical input and output specifications and ratings apply to the digital T O lines All voltages are with respect to DGND 3 18 National Instruments Corporation Logical Input and Output National Instruments Corporation Absolute maximum voltage rating Digital I O lines Input logic low voltage Input logic high voltage Output logic low voltage Chapter 3 Signal Connections 0 5 to 5 5 V with respect to DGND 0 3 V min 0 8 V max 2 2 V min 5 3 V max 0 4 V max at output sink current 2 5 mA Output logic high voltage 3 7 V min at output source current 2 5 mA Input leakage current 0 lt Vin lt 5 V 1 uA min 1 pA max Lab PC 1200 Al User Manual Chapter 3 Signal Connections Figure 3 9 illustrates signal connections for three typical digital I O applications LED 5 V P 5 V lt NW 4 A Port A 14 PA WW o PA lt 7 0 gt De 22 PBO Pons PB lt 7 0 gt TTL Signal _ 30 PCO Port C I PC lt 7 0 gt Switch 13 ye DGND l O Connector 1
41. DAQ Lab PC 1200 Al User Manual Multifunctional 1 0 Board for the PC AT Ay NATIONAL ma July 1998 Editi gt INSTRUMENTS Part Ati SCDOT Internet Support E mail support natinst com FTP Site ftp natinst com Web Address www natinst com Bulletin Board Support BBS United States 512 794 5422 BBS United Kingdom 01635 551422 BBS France 01 48 65 15 59 Fax on Demand Support 512418 1111 Telephone Support USA Tel 512 795 8248 Fax 512 794 5678 International Offices Australia 03 9879 5166 Austria 0662 45 79 90 0 Belgium 02 757 00 20 Brazil 011 288 3336 Canada Ontario 905 785 0085 Canada Qu bec 514 694 8521 Denmark 45 76 26 00 Finland 09 725 725 11 France 01 48 14 24 24 Germany 089 741 31 30 Hong Kong 2645 3186 Israel 03 6120092 Italy 02 413091 Japan 03 5472 2970 Korea 02 596 7456 Mexico 5 520 2635 Netherlands 0348 433466 Norway 32 84 84 00 Singapore 2265886 Spain 91 640 0085 Sweden 08 730 49 70 Switzerland 056 200 51 51 Taiwan 02 377 1200 United Kingdom 01635 523545 National Instruments Corporate Headquarters 6504 Bridge Point Parkway Austin Texas 78730 5039 USA Tel 512 794 0100 Copyright 1996 1998 National Instruments Corporation All rights reserved Important Information Warranty Copyright Trademarks The Lab PC 1200 and Lab PC 1200AI are warranted against defects in materials and workmanship for a period of one year from the date of shipment as evidenced by receipts or oth
42. Scanning Acquisition Mode The 1200 Series boards use two counters for interval scanning data acquisition Counter B1 times the scan interval Counter AO times the sample interval In interval scanning analog input operations scan sequences are executed at regular specified intervals The amount of time that elapses between consecutive scans within the sequence is the sample interval The amount of time that elapses between consecutive scan sequences is the scan interval LabVIEW LabWindows CVI and NI DAQ support only multichannel interval scanning Single channel interval scanning is available only through register level programming Because interval scanning allows you to specify how frequently scan sequences are executed it is useful for applications in which you need to sample data at regular but relatively infrequent intervals For example to sample channel 1 wait 12 us sample channel 0 then repeat this process every 65 ms Then define the operation as follows e Start channel chl which gives a scan sequence of ch1 ch0 e Sample interval 12 us e _ Scan interval 65 ms The first channel will not be sampled until one sample interval from the scan interval pulse Since the A D conversion time is 10 us your sample interval must be at least this value to ensure proper operation National Instruments Corporation 4 9 Lab PC 1200 Al User Manual Chapter 4 Theory of Operation Single Channel Data Acquisition The 1200
43. Series boards execute a single channel analog input operation by performing an A D conversion on a specified analog input channel every sample interval The sample interval is the amount of time that elapses between successive A D conversions The sample interval is controlled either externally by EXTCONV or internally by counter AO To specify a single channel analog input operation select an analog input channel and a gain setting for that channel Multichannel Scanned Data Acquisition The 1200 Series boards execute a multichannel data acquisition operation by repeatedly scanning a sequence of analog input channels the same gain is applied to each channel in the sequence The channels are scanned in decreasing consecutive order the highest numbered channel is the start channel and channel 0 is the last channel in the sequence During each scan sequence the 1200 Series board scans the start channel the highest numbered channel first then the next highest numbered channel and so on until it scans channel 0 It repeats these scan sequences until the data acquisition operation stops For example if channel 3 is specified as the start channel the scan sequence is as follows ch3 ch2 ch1 chO ch3 ch2 chl ch0 ch3 ch2 To specify the scan sequence for a multichannel scanned analog input operation you select the start channel for the scan sequence and a gain setting Data Acquisition Rates Lab PC 1200 Al User Manual
44. alog output A bipolar configuration has a range of 5 to 5 V at the analog output If you select a bipolar range data values written to the analog output channel range from 2 048 to 2 047 F800 hex to 7FF hex If you select a unipolar range for a DAC the data values written to the analog output channel range from 0 to 4 095 0 to FFF hex Analog Input Polarity You can select the analog input on the 1200 Series board for either a unipolar range 0 to 10 V or a bipolar range 5 to 5 V If you select a bipolar range 5 V input corresponds to F800 hex 2 048 decimal and 5 V corresponds to 7FF hex 2 047 decimal If you select a unipolar mode 0 V input corresponds to 0 hex and 10 V corresponds to FFF hex 4 095 decimal Lab PC 1200 Al User Manual 2 8 National Instruments Corporation Chapter 2 Installation and Configuration Analog Input Mode The 1200 Series boards have three different input modes RSE input NRSE input and DIFF input The single ended input configurations use eight channels The DIFF input configuration uses four channels Table 2 5 describes these configurations Table 2 5 Analog Input Modes for the 1200 Series Boards Analog Input Modes Description RSE RSE mode provides eight single ended inputs with the negative input of the instrumentation amplifier referenced to analog ground reset condition NRSE NRSE mode provides eight single ended inputs with the negative input of the i
45. ase notes to install your driver software Find the installation section for your operating system and follow the instructions given there If you are using LabVIEW refer to your Lab VIEW release notes to install your application software After you have installed LabVIEW refer to the NI DAQ release notes and follow the instructions given there for your operating system and LabVIEW If you are using LabWindows CVI refer to your LabWindows CVI release notes to install your application software After you have installed LabWindows CVI refer to the NI DAQ release notes and follow the instructions given there for your operating system and LabWindows CVI Hardware Installation a Note You should install your NI DAQ software before installing your hardware Refer to your NI DAQ release notes for software installation instructions You can install your 1200 Series board in any unused expansion slot in your computer The following are general installation instructions Consult your computer user manual or technical reference manual for specific instructions and warnings 1 Write down your board serial number in the hardware and software configuration form in Appendix B Customer Communication You will need this information when you install and configure your board 2 Turn off your computer Remove the top cover or access port to the I O channel 4 Remove the expansion slot cover on the back panel of the computer National Instru
46. ation floating signal sources 3 12 to 3 13 grounded referenced signal sources 3 11 to 3 12 single ended connections 3 14 exceeding maximum input voltage ratings caution 3 7 floating signal sources 3 9 ground referenced signal sources 3 9 input configurations 3 10 to 3 17 input signal range versus gain table bipolar 3 7 unipolar 3 7 to 3 8 instrumentation amplifier 3 8 pins 3 6 single ended connections floating signal sources RSE configuration 3 14 to 3 15 grounded signal sources NRSE configuration 3 15 to 3 16 summary of input configurations table 3 10 types of signal sources 3 9 analog input specifications A 1 to A 2 amplifier characteristics A 3 dynamic characteristics A 3 to A 4 explanation A 4 to A 5 input characteristics A 1 to A 2 stability A 4 transfer characteristics A 2 analog I O configuration Lab PC 1200 default configuration 2 7 settings table 2 7 Lab PC 1200AI default configuration 2 7 settings table 2 8 analog output Lab PC 1200 Al User Manual Index circuitry 4 12 to 4 13 polarity 2 8 signal connections 3 17 to 3 18 specifications A 6 to A 7 dynamic characteristics A 7 explanation A 7 output characteristics A 6 stability A 7 transfer characteristics A 6 voltage output A 7 Analog to Digital Converter ADC 4 7 to 4 8 base I O address selection 2 3 bipolar analog input signal range vs gain table 3 7 bulletin board support B 1 bus interface
47. ations for signal voltage and current specifications The following specifications and ratings apply to the 82C53 I O signals e Absolute maximum voltage input rating 0 5 to 5 5 V with respect to DGND e 82C53 digital input specifications referenced to DGND V p input logic high voltage 2 2 V min 5 3 V max V input logic low voltage __ 0 3 V min 0 8 V max _ Input load current 10 uA min 10 WA max Lab PC 1200 Al User Manual 3 28 National Instruments Corporation Vin CLK VIL VIH GATE VIL Von OUT VoL Chapter 3 Signal Connections 82C53 digital output specifications referenced to DGND Von output logic high voltage 3 7 V min Vo output logic low voltage Top output source current at Veg Io output sink current at Var 0 45 V max 0 92 mA max 2 1 mA max Figure 3 17 shows the timing requirements for the GATE and CLK input signals and the timing specifications for the 82C53 OUT output signals tsc gt lt towh gt lt towl gt gt gy i th ee 4 tgwh dn t towl gt _ tug gt toute gt tec clock period 380 ns minimum town Clock high level 230 ns minimum tow clock low level 150 ns minimum tysu gate setup time 100 ns minimum ton gate hold time 50 ns minimum town gate high level 150 ns minimum tow gate low level 100 ns minimum toutg Output delay from clock 4 300 ns maximum toute Output delay fr
48. aximum error of 0 02 at all gains The 1200 Series boards are factory calibrated at all gains and NI DAQ automatically loads the correct values into the calibration DACs whenever you switch gains Calibration Equipment Requirements Lab PC 1200 Al User Manual The equipment you use to calibrate your 1200 Series board should have a 0 001 rated accuracy which is 10 times as accurate as the board However calibration equipment with only four times the accuracy as the board and a 0 003 rated accuracy is acceptable The inaccuracy of the calibration equipment results only in gain error offset error is unaffected Calibrate your 1200 Series board to a measurement accuracy of 0 5 LSBs which is within 0 012 of its input range 5 2 National Instruments Corporation Chapter 5 Calibration For analog input calibration use a precision DC voltage source such as a calibrator with the following specifications e Voltage Oto 10 V e Accuracy 0 001 standard 0 003 acceptable Using the Calibration Function NI DAQ contains the Calibrate_1200 function with which you can either load the calibration DACs with the factory constants or the user defined constants stored in the EEPROM or you can perform your own calibration and directly load these constants into the calibration DACs To use the Calibrate_1200 function for analog input calibration ground an analog input channel at the I O connector for offset calibration and appl
49. counter timer circuitry which counts the total number of samples taken during a controlled operation or through software in a freerun operation Controlled Acquisition Mode The 1200 Series boards use two counters counter AO and counter Al to execute data acquisition operations in controlled acquisition mode Counter AO is used as a sample interval counter while counter Al is used as a sample counter In controlled acquisition mode the board performs a specified number of conversions and then the hardware shuts off the conversions Counter AO generates the conversion pulses and counter Al gates off counter AO after the programmed count has expired The number of conversions in a single controlled acquisition mode data acquisition operation is limited to a 16 bit count 65 535 conversions 4 8 National Instruments Corporation Chapter 4 Theory of Operation Freerun Acquisition Mode The 1200 Series boards use one counter counter AO to execute data acquisition operations in freerun acquisition mode Counter AO continuously generates the conversion pulses as long as GATEAO is held at a high logic level The software keeps track of the number of conversions that have occurred and turns off counter AO either after the required number of conversions has been obtained or after some other user defined criteria have been met The number of conversions in a single freerun acquisition mode data acquisition operation is unlimited Interval
50. e CLK and GATE signals at the I O connector control the counters The single exception is counter BO which has an internal 2 MHz clock To perform pulse and square wave generation program a counter to generate a timing signal at its OUT output pin To perform event counting program a counter to count rising or falling edges applied to any of the 82C53 CLK inputs then read the counter value to determine the number of edges that have occurred You can enable or disable the counting operation by controlling the gate input Figure 3 15 shows connections for a typical event counting operation in which a switch gates the counter on and off 3 26 National Instruments Corporation Chapter 3 Signal Connections So Switch Counter from Group B Signal Source nt l O Connector 1200 Series Complex switch circuitry is not shown in order to simplify the figure Figure 3 15 Event Counting Application with External Switch Gating Level gating performs pulse width measurement The pulse you want to measure is applied to the counter GATE input Load the counter with the known count and program it to count down while the signal at the GATE input is high The pulse width equals the counter difference loaded value minus read value multiplied by the CLK period Perform time lapse measurement by programming a counter to be edge gated Apply an edge to
51. e I O pins These pins represent the three 8 bit I O ports A B and C of the 82C55A as well as PA lt 0 7 gt PB lt 0 7 gt and PC lt 0 7 gt on the 1200 Series I O connector Figure 4 7 shows the digital I O circuitry Address 17 Data 8 Control 4 DMA 3 Interrupt PC I O Channel ISA PnP Chip 1 Address gt A gt PA lt 0 7 gt Data DATA lt 0 7 gt 8 Digital q 7 gt PB lt 0 7 gt Control DIO RD WRT 8 Control 82C55A 5 Logic Programmable lt 2 PC lt 0 7 gt DMA Peripheral 8 Z gt Interface 7 Interrupt Q 1 PCO PC3 National Instruments Corporation Figure 4 7 Digital I O Circuitry All three ports on the 82C55A are TTL compatible When enabled the digital output ports can sink 2 5 mA of current and can source 2 5 mA of current on each digital I O line When the ports are not enabled the digital T O lines act as high impedance inputs Lab PC 1200 Al User Manual Calibration This chapter discusses the calibration procedures for the 1200 Series analog I O circuitry However the 1200 Series boards are factory calibrated and National Instruments can recalibrate your board if needed To maintain the 12 bit accuracy of the board analog input circuitry recalibrate at 6 month intervals If you have a Lab PC 1200 you should also recalibrate the analog output circuitry at 6 month intervals There are
52. e computer s power supply via a self resetting fuse The fuse will reset automatically within a few seconds after you remove the overcurrent condition Pin 49 is referenced to DGND and you can use the 5 V to power external digital circuitry e Power rating 1 A at 4 65 to 5 25 V AN Warning Do not directly connect this 5 V power pin to analog or digital ground or to any other voltage source on the 1200 Series or any other device Doing so can damage the 1200 Series board or your computer National Instruments is NOT liable for any damage due to incorrect power connections Data Acquisition and General Purpose Timing Signal Connections Pins 38 through 48 of the I O connector are connections for timing I O signals The 1200 Series timing input output circuitry uses two 82C53 counter timer integrated circuits One counter the 82C53 A is used exclusively for data acquisition timing and the other 82C53 B is available for general use Use pins 38 through 40 and pin 43 to carry external signals for data acquisition timing These signals are explained in the Data Acquisition Timing Connections Pins 41 through 48 carry general purpose timing signals from 82C53 B These signals are explained in the General Purpose Timing Signal Connections later in this chapter National Instruments Corporation 3 21 Lab PC 1200 Al User Manual Chapter 3 Signal Connections Data Acquisition Timing Connections Each 82C53 counter timer circuit contains
53. edure or equipment used to monitor or safeguard human health and safety in medical or clinical treatment Contents About This Manual Organization of This Manual nonnen venne ens enseenvenvennvenvennveneerneeneeenvenven ix Conventions Used in This Manual ccccessesssececceceecesseceeeeesaeceneeceeecsaeeeeeeeseeesaeeeeeees xX National Instruments Documentation neen soon venne venne renseenverenversnvensereenvenneeenn xi Related Docum nt ti h iera a aaee raaa Eai a TEER Ea EE Aa AEE ERA ova xii Customer CommunicatiOn eresie rE sire ESEE EE EEE AE E Ei xii Chapter 1 Introduction About the LabtPC 1200 A niinn E nets 1 1 What You Need to Get Started aaan oen enneronneenneeenervenvennerenverenveeneeeene 1 1 Unpacking cies sis serene nettere niel genes sss atk hee erde Redenen bee 1 2 Software Programming Choices nennen onnerneorneenevenverneenveenvenvennvenvennvenvennen 1 2 LabVIEW and LabWindows CVI Application Software eee 1 2 NI DAQ Driver Software nnen ra E e a e e ee enen 1 3 Register Level Programming nnn enner enne sirni ission i inisi iess 1 4 Optional Equipment serene eerdere anenveneenined eeno ees rees EESE EENES EES ER aneh 1 5 Custom Cabling enee r Eea r r a n Sei onderin T EErEE REEE E S 1 5 Chapter 2 Installation and Configuration Software Install ttOns ansessossebsnneenetien tenet dh O TATER 2 1 Hardware Installation Stes iets hockii tis cada Ate Wienke 2 1 Hardwa
54. egative input voltage common mode noise volts direct current differential input voltage ground loop losses video graphics array 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 software module VI which consists of a front panel user interface and a block diagram program volts input high volts input low measured voltage DAC output voltages signal source write signal G 8 National Instruments Corporation Index Numbers 5 V signal table 3 6 A ACH lt 0 7 gt signal analog input signal range vs gain table bipolar 3 7 unipolar 3 7 to 3 8 definition table 3 4 exceeding input range caution 3 7 ACK signal description table 3 30 mode 1 output timing figure 3 32 mode 2 bidirectional timing figure 3 33 A D FIFO 4 7 ADC Analog to Digital Converter 4 7 to 4 8 AGND signal table 3 4 AISENSE AIGND signal definition table 3 4 using for general analog power ground tie 3 6 analog input circuitry block diagram 4 6 theory of operation 4 6 to 4 8 analog input modes DIFF 2 10 NRSE 2 10 RSE 2 9 summary table 2 9 analog input polarity 2 8 analog input settling time versus gain table 4 11 analog input signal connections common mode signal rejection 3 16 to 3 17 differential connections 3 11 National Instruments Corpor
55. election is software configured and does not require you to manually change any board settings DMA Channel Selection The 1200 Series boards can use one DMA channel for data transfers with the analog input section of the board The 1200 Series boards can use DMA channels or 3 These selections are all software configured and do not require you to manually change any board settings Interrupt Channel Selection The 1200 Series boards can increase bus efficiency by using an interrupt channel You can use an interrupt channel for event notification without using polling techniques The 1200 Series boards can use interrupt channels 3 4 5 7 or 9 These selections are all software configured and do not require you to manually change any board settings Tables 2 1 and 2 2 provide information concerning possible resource conflicts when configuring your 1200 Series board National Instruments Corporation 2 3 Lab PC 1200 Al User Manual Chapter 2 Installation and Configuration Lab PC 1200 Al User Manual Table 2 1 PC AT I O Address Map I O Address Range Hex Device 100 to IEF Unreserved 1F0 to FF IBM PC AT Fixed Disk 200 to 20F PC and PC AT Game Controller reserved 210 to 213 PC DIO 24 default 218 to 21F Unreserved 220 to 23F Previous generation of AT MIO boards default 240 to 25F AT DIO 32F default 260 to 27F Lab PC default
56. en 0 Voltage Noise oOo and so on lt 7 l O Connector 1200 Series in NRSE Input Configuration Lab PC 1200 Al User Manual Figure 3 7 Single Ended Input Connections for Grounded Signal Sources Common Mode Signal Rejection Considerations Figures 3 5 and 3 7 show connections for signal sources that are already referenced to some ground point with respect to the 1200 Series In these cases the instrumentation amplifier can reject any voltage caused by ground potential differences between the signal source and the 1200 Series board In addition with differential input connections the instrumentation amplifier can reject common mode noise pickup in the leads connecting the signal sources to the 1200 Series board 3 16 National Instruments Corporation Chapter 3 Signal Connections The common mode input range of the instrumentation amplifier is the magnitude of the greatest common mode signal that it can reject The common mode input range for the 1200 Series depends on the size of the differential input signal V girs V in V in and the gain setting of the instrumentation amplifier In unipolar mode the differential input range is 0 to 10 V In bipolar mode the differential input range is 5 to 5 V In differential or NRSE mode the negative input AISENSE should remain within 5 V bipolar input range or 5 to 2 V unipolar input range of AGND The positive input should remain within 5 V
57. ent Form National Instruments encourages you to comment on the documentation supplied with our products This information helps us provide quality products to meet your needs Title Lab PC 1200 AI User Manual Edition Date July 1998 Part Number 371350A 01 Please comment on the completeness clarity and organization of the manual If you find errors in the manual please record the page numbers and describe the errors Thank you for your help Name Title Company Address E Mail Address Phone Fax Mail to Technical Publications Faxto Technical Publications National Instruments Corporation National Instruments Corporation 6504 Bridge Point Parkway 512 794 5678 Austin Texas 78730 5039 Glossary Prefix Meanings Value p pico 10 2 n nano 10 9 u micro 10 6 m milli 10 3 k kilo 103 M mega 106 G giga 10 t tera 10 Numbers Symbols 7 degrees gt greater than gt greater than or equal to lt less than negative of or minus not equal to Q ohms percent plus or minus positive of or plus 5 V 5 Volts signal National Instruments Corporation G 1 Lab PC 1200 Al User Manual Glossary A A ACH lt 0 7 gt ACK A D ADC AGND Al AISENSE AIGND ANSI AO AVAIL BBS BSC C c CH CLKB1 CLKB2 cm CNTINT Lab PC 1200 Al Use
58. er documentation National Instruments will at its option repair or replace equipment that proves to be defective during the warranty period This warranty includes parts and labor The media on which you receive National Instruments software are warranted not to fail to execute programming instructions due to defects in materials and workmanship for a period of 90 days from date of shipment as evidenced by receipts or other documentation National Instruments will at its option repair or replace software media that do not execute programming instructions if National Instruments receives notice of such defects during the warranty period National Instruments does not warrant that the operation of the software shall be uninterrupted or error free A Return Material Authorization RMA number must be obtained from the factory and clearly marked on the outside of the package before any equipment will be accepted for warranty work National Instruments will pay the shipping costs of returning to the owner parts which are covered by warranty National Instruments believes that the information in this manual is accurate The document has been carefully reviewed for technical accuracy In the event that technical or typographical errors exist National Instruments reserves the right to make changes to subsequent editions of this document without prior notice to holders of this edition The reader should consult National Instruments if errors are suspected
59. ernal Read Signal This signal is the read signal generated from the interface circuitry WRT Internal Write Signal This signal is the write signal generated from the inter face circuitry DATA _ Bidirectional Data Lines at the Specified Port This signal indicates when the data on the data lines at a specified port is or should be available Lab PC 1200 Al User Manual 3 30 National Instruments Corporation Chapter 3 Signal Connections Mode 1 Input Timing The timing specifications for an input transfer in mode are as follows 72 bn 1 lt gt STB o i Ot aat Eog i D IBF i l i Te o 1 I lt gt i INTR RD 1 i i T3 i T5 i DATA Name Description Minimum Maximum Tl STB pulse width 500 ns T2 STB 0 to IBF 1 300 T3 Data before STB 1 0 T4 STB 1 to INTR 1 300 T5 Data after STB 1 180 T6 RD 0 to INTR 0 400 T7 RD 1 to IBF 0 300 All timing values are in nanoseconds Figure 3 18 Mode 1 Timing Specifications for Input Transfers National Instruments Corporation 3 31 Lab PC 1200 Al User Manual Chapter 3 Signal Connections Mode 1 Output Timing The timing specifications for an output transfer in mode 1 are as follows oe WRT Ln TA 1 1 1 Dn gt OBE TT 4 ioo Te
60. explains how to build custom cables and unpack your board About the Lab PC 1200 Al Thank you for purchasing the Lab PC 1200 or Lab PC 1200AI board These boards are low cost high performance analog digital and timing boards for PC AT and compatible computers Additionally the Lab PC 1200 has analog output capabilities The 1200 Series boards have eight analog input channels that you can configure as eight single ended or four differential inputs a 12 bit successive approximation ADC 24 lines of TTL compatible digital I O and three 16 bit counter timers for timing TO The 1200 Series boards are completely switchless and jumperless data acquisition boards This allows DMA interrupts and base I O addresses to be assigned by your system to avoid resource conflicts with other boards in your system These boards are designed for high performance data acquisition and control for applications in laboratory testing production testing and industrial process monitoring and control Detailed specifications for your 1200 Series board are in Appendix A Specifications What You Need to Get Started To set up and use your 1200 Series boards you will need the following Q One of the following boards Lab PC 1200 Lab PC 1200AI Q Lab PC 1200 AI User Manual National Instruments Corporation 1 1 Lab PC 1200 Al User Manual Chapter 1 Introduction Unpacking 0 One of the following software packages and documentation LabVIEW for
61. ferenced to the same common mode voltage which floats with respect to the board analog ground This common mode voltage is subsequently subtracted by the input instrumentation amplifier The NRSE configuration is useful for measuring ground referenced signal sources Considerations for using the NRSE configuration are discussed in Chapter 3 Signal Connections Notice that in this mode the signal return path is through the negative terminal of the amplifier at the connector through the AISENSE AIGND pin DIFF Input Four Channels DIFF input means that each input signal has its own reference and the difference between each signal and its reference is measured The signal and its reference are each assigned an input channel With this input configuration the 1200 Series board can monitor four differential analog input signals Considerations for using the DIFF configuration are discussed in Chapter 3 Signal Connections Notice that the signal return path is through the amplifier s negative terminal and through channel 1 3 5 or 7 depending on which channel pair you select 2 10 National Instruments Corporation Signal Connections This chapter describes how to make input and output signal connections to the 1200 Series boards via the board I O connector and details the I O timing specifications The I O connector for the 1200 Series boards has 50 pins that you can connect to 50 pin accessories 1 0 Connector Figu
62. four ways to calibrate your board e If you have LabVIEW use the 1200 Calibrate VI This VI is located in the Calibration and Configuration palette e Ifyou have LabWindows CVI use the Calibrate_1200 function e If you do not have LabVIEW or LabWindows CVI use the NI DAQ Calibrate_1200 function e Use your own register level writes to the calibration DACs and the EEPROM To calibrate using the last method you need to know the details of the calibration process This information is in the Lab PC 1200 AI Register Level Programmer Manual Use the last calibration method only if NI DAQ does not support your operating system The 1200 Series boards are software calibrated The calibration process involves reading offset and gain errors from the analog input section also the analog output section if you have a Lab PC 1200 and writing values to the appropriate calibration DACs to null the errors There are four calibration DACs associated with the analog input section Lab PC 1200 The Lab PC 1200 has an additional four calibration DACs associated with the analog output section two for each output channel After the calibration process is complete each calibration DAC is at a known value Because these values are lost when the board is powered down they are also stored in the onboard EEPROM for future reference National Instruments Corporation 5 1 Lab PC 1200 Al User Manual Chapter 5 Calibration The factory informat
63. g output circuitry 4 12 to 4 13 DAC timing 4 13 Lab PC 1200 analog output circuitry figure 4 12 block diagram Lab PC 1200 4 1 Lab PC 1200AI 4 2 digital I O 4 13 functional overview 4 1 to 4 2 PC I O channel interface circuitry 4 2 to 4 3 timing circuitry 4 3 to 4 5 time lapse measurement 3 27 timing circuitry block diagram 4 4 theory of operation 4 3 to 4 5 timing I O specifications A 8 to A 9 timing signal connections See data acquisition timing connections general purpose timing signal connections timing specifications 3 30 to 3 33 mode input timing 3 31 mode output timing 3 32 mode 2 bidirectional timing 3 33 U unipolar analog input signal range vs gain table 3 7 to 3 8 unpacking the Lab PC 1200 AI 1 2 W WRT signal description table 3 30 mode 1 output timing figure 3 32 mode 2 bidirectional timing figure 3 33 National Instruments Corporation
64. gm POSTTRIG PnP PPI ppm PRETRIG R RD REQ RMA RSE RTD Lab PC 1200 Al User Manual output buffer full signal counter BO B1 output signals overflow error overrun error port A B or C 0 through 7 signals personal computer program postrigger mode Plug and Play programmable peripheral interface parts per million pretrigger mode read signal request return material authorization root mean square referenced single ended mode all measurements are made with respect to a common reference measurement system or a ground Also called a grounded measurement system resistance temperature detector G 6 National Instruments Corporation SCXI STB seconds samples Glossary Signal Conditioning eXtensions for Instrumentation the National Instruments product line for conditioning low level signals within an external chassis near sensors so only high level signals are sent to DAQ boards in the noisy PC environment strobe input signal minimum period gate hold time gate setup time gate high level gate low level minimum pulse width output delay from gate output delay from clock clock high level clock low level clock period transistor transistor logic typical National Instruments Corporation G 7 Lab PC 1200 Al User Manual Glossary U UP BP VGA VI VOUTO VOUTI y S W WRT Lab PC 1200 Al User Manual unipolar bipolar bit volts positive n
65. he 1200 Series board in the DIFF mode Each input signal is tied to the positive input of the instrumentation amplifier and its reference signal or return is tied to the negative input of the instrumentation amplifier When configuring the 1200 Series for DIFF input each signal uses two of the multiplexer inputs one for the signal and one for its reference signal Therefore only four analog input channels are available when using the DIFF configuration Use the DIFF input configuration when your DAQ system has any of the following conditions e Input signals are low level less than 1 V e Leads connecting the signals to the 1200 Series board are greater than 10 ft e Any of the input signals require a separate ground reference point or return signal e The signal leads travel through noisy environments Differential signal connections reduce picked up noise and increase common mode signal and noise rejection With these connections input signals can float within the common mode limits of the input instrumentation amplifier National Instruments Corporation 3 11 Lab PC 1200 Al User Manual Chapter 3 Signal Connections Differential Connections for Ground Referenced Signal Sources Figure 3 4 shows how to connect a ground referenced signal source to a 1200 Series board configured for DIFF input Configuration instructions are in the Analog I O Configuration section in Chapter 2 Installation and Configuration
66. i a lt gt INTR ACK 3 DATA D ger E Name Description Minimum Maximum T1 WRT 0 to INTR 0 450 T2 WRT 1 to output 350 T3 WRT 1 to OBF 0 650 T4 ACK 0 to OBF 1 350 T5 ACK pulse width 300 T6 ACK 1 to INTR 1 350 All timing values are in nanoseconds Figure 3 19 Mode 1 Timing Specifications for Output Transfers Lab PC 1200 Al User Manual 3 32 National Instruments Corporation Chapter 3 Signal Connections Mode 2 Bidirectional Timing The timing specifications for bidirectional transfers in mode 2 are as follows a cee gt WRT i T6 OBF INTR i I T7 1 En ACK tg gs STB TO an i 1 1 T10 1 nn 5 IBF RD 3 1 T2 iTS 1 1 T8 mt T9 1 P Name Description Minimum Maximum Tl WRT 1 to OBF 0 650 T2 Data before STB 1 0 T3 STB pulse width 500 T4 STB 0 to IBF 1 300 T5 Data after STB 1 180 T6 ACK 0 to OBF 1 350 T7 ACK pulse width 300 T8 ACK 0 to output 300 T9 ACK 1 to output float 20 250 T10 RD 1 to IBF 0 300 All timing values are in nanoseconds Figure 3 20 Mode 2 Timing Specification for Bidirectional Transfers National Instruments Corporation 3 33 Lab PC 1200 Al User Manual Theory of Operation This chapter explains the ope
67. ins a 12 bit DAC The DAC in each analog output channel generates a voltage proportional to the 10 V internal reference multiplied by the 12 bit digital code loaded into the DAC The voltage output from the two DACs is available at the DACOOUT and DACIOUT pins You can program each DAC channel for a unipolar voltage output or a bipolar voltage output range A unipolar output gives an output voltage range of 0 0000 to 9 9976 V A bipolar output gives an output voltage range of 5 0000 to 4 9976 V For unipolar output 0 0000 V output corresponds to a digital code word of 0 4 12 National Instruments Corporation DAC Timing Digital 1 0 Chapter 4 Theory of Operation For bipolar output 5 0000 V output corresponds to a digital code word of F800 hex One LSB is the voltage increment corresponding to an LSB change in the digital code word For both outputs 1Lsp CV 4 095 You can update the DAC voltages in two modes In immediate update mode the DAC output voltage is updated as soon as you write to the corresponding DAC In delayed update mode the DAC output voltage does not change until a low level is detected either from counter A2 of the timing circuitry or EXTUPDATE This mode is useful for waveform generation These two modes are software selectable The digital I O circuitry for the 1200 Series has an 82C55A integrated circuit The 82C55A is a general purpose programmable peripheral interface containing 24 programmabl
68. ion occupies one half of the EEPROM and is write protected The lower half of the EEPROM contains user areas for calibration data There are four different user areas outlined in the Lab PC 1200 AI Register Level Programmer Manual When the board is powered on or the conditions under which itis operating change you must load the calibration DACs with the appropriate calibration constants If you use your 1200 Series board with NI DAQ LabVIEW or LabWindows CVI the factory calibration constants are automatically loaded into the calibration DAC the first time a function pertaining to the board is called and again each time you change your configuration which includes gain You can instead choose to load the calibration DACs with calibration constants from the user areas in the EEPROM or you can recalibrate the board and load these constants directly into the calibration DACs Calibration software is included with the 1200 Series as part of the NI DAQ software Calibration at Higher Gains The 1200 Series boards have a maximum gain error of 0 8 This means that if the board is calibrated at a gain of 1 and if the gain is switched to 100 a maximum of 32 LSB error may result in the reading Therefore when you are recalibrating your 1200 Series board you should perform gain calibration at all other gains 2 5 10 20 50 and 100 and store the corresponding values in the user gain calibration data area of the EEPROM thus ensuring a m
69. k Controller 13 Coprocessor 12 AT DIO 32F default 11 AT DIO 32F default 10 AT MIO 16 default 9 PC Network default PC Network Alternate default 8 Real Time Clock 7 Parallel Port 1 LPT1 6 Diskette Drive Controller Fixed Disk and Diskette Drive Controller 5 Parallel Port 2 LPT2 PC DIO 24 default Lab PC default Lab PC 1200 AI recommended in switchless mode 4 Serial Port 1 COM1 BSC BSC Alternate 3 Serial Port 2 COM2 BSC BSC Alternate Cluster primary PC Network PC Network Alternate WD EtherCard default 3Com EtherLink default 2 IRQ 8 15 Chain from interrupt controller 2 1 Keyboard Controller Output Buffer Full 0 Timer Channel 0 Output Lab PC 1200 Al User Manual 2 6 National Instruments Corporation Chapter 2 Installation and Configuration Data Acquisition Related Configuration Analog 1 0 Configuration Lab PC 1200 Upon power up or after a software reset the Lab PC 1200 is set to the following configuration e Referenced single ended input mode e 5 V analog input range bipolar e 5 V analog output range bipolar Table 2 3 lists all of the available analog I O configurations for the Lab PC 1200 and shows the configuration in reset condition Table 2 3 Analog I O Settings Lab PC 1200 Parameter Configuration Analog Output CHO Polarity Bipolar 5 V reset condition Uni
70. ments Corporation 2 1 Lab PC 1200 Al User Manual Chapter 2 Installation and Configuration 5 Insert the board into an unused 8 bit or 16 bit ISA slot The fit may be tight but do not force the board into place 6 Screw the board s mounting bracket to the back panel rail of the computer to secure the 1200 Series board in place 7 Check the installation 8 Replace the top cover on the computer Your 1200 Series board is installed You are now ready to configure your board Hardware Configuration The 1200 Series boards are completely software configurable Two types of configuration are performed on the board bus related and data acquisition related Bus related configuration includes setting the base I O address DMA channel and interrupt channel Data acquisition related configuration includes such settings as analog I O polarity selection range selection digital I O configuration and other settings For more information about data acquisition related configuration refer to your NI DAQ documentation Bus Related Configuration Lab PC 1200 Al User Manual Your 1200 Series board works in either a Plug and Play mode or a switchless mode These modes dictate how the base I O address DMA channel and interrupt channel are determined and assigned to the board Plug and Play Mode The 1200 Series boards are fully compatible with the industry standard Intel Microsoft Plug and Play Specification version 1 0 Your Plug and
71. n use to comment on the product documentation When you contact us we need the information on the Technical Support Form and the configuration form if your manual contains one about your system configuration to answer your questions as quickly as possible National Instruments has technical assistance through electronic fax and telephone systems to quickly provide the information you need Our electronic services include a bulletin board service an FTP site a fax on demand system and e mail support If you have a hardware or software problem first try the electronic support systems If the information available on these systems does not answer your questions we offer fax and telephone support through our technical support centers which are staffed by applications engineers Electronic Services Bulletin Board Support National Instruments has BBS and FTP sites dedicated for 24 hour support with a collection of files and documents to answer most common customer questions From these sites you can also download the latest instrument drivers updates and example programs For recorded instructions on how to use the bulletin board and FTP services and for BBS automated information call 512 795 6990 You can access these services at United States 512 794 5422 Up to 14 400 baud 8 data bits 1 stop bit no parity United Kingdom 01635 551422 Up to 9 600 baud 8 data bits 1 stop bit no parity France 01 48 65 15 59 Up to 9 600 baud 8 da
72. nal Instruments Corporation Figure 3 6 Single Ended Input Connections for Floating Signal Sources Single Ended Connections for Grounded Signal Sources NRSE Configuration If you measure a grounded signal source with a single ended configuration configure the 1200 Series in the NRSE input configuration The signal connects to the positive input of the 1200 Series instrumentation amplifier and the signal local ground reference connects to the negative input of the 1200 Series instrumentation amplifier Therefore connect the ground point of the signal to the AISENSE pin Any potential difference between the 1200 Series ground and the signal ground appears as a common mode signal at both the positive and negative inputs of the instrumentation amplifier and is therefore rejected by the amplifier On the other hand if Lab PC 1200 Al User Manual Chapter 3 Signal Connections the input circuitry of the 1200 Series is referenced to ground such as in the RSE configuration this difference in ground potentials appears as an error in the measured voltage Figure 3 7 shows how to connect a grounded signal source to a 1200 Series board configured in the NRSE configuration Configuration instructions are in the Analog I O Configuration section of Chapter 2 Installation and Configuration Ground Referenced Signal a 8 ACH7 Source os sy 9 Common Measured AISENSE AIGND Mode 11 AGND han
73. nd Your Hardware Register Level Programming The final option for programming any National Instruments DAQ hardware is to write register level software Writing register level programming software can be very time consuming and inefficient and is not recommended for most users Even if you are an experienced register level programmer consider using NI DAQ LabVIEW or LabWindows CVI to program your National Instruments DAQ hardware Using the NI DAQ LabVIEW or LabWindows CVI software is easier than and as flexible as register level programming and can save weeks of development time Lab PC 1200 Al User Manual 1 4 National Instruments Corporation Chapter 1 Introduction Optional Equipment National Instruments offers a variety of products to use with your Lab PC 1200 AI board including cables connector blocks and other accessories as follows e Cables and cable assemblies e Connector blocks 50 pin screw terminals e SCXI modules and accessories for isolating amplifying exciting and multiplexing signals for relays and analog output With SCXI you can condition and acquire up to 3 072 channels The SCXI 1341 adapter is needed to use the Lab PC 1200 AI with SCXT e Low channel count signal conditioning modules boards and accessories including conditioning for strain gauges and RTDs simultaneous sample and hold and relays For specific information about these products refer to your National Instruments catalog
74. nd use 3 14 when to use 3 14 software installation 2 1 software programming choices LabVIEW and LabWindows CVI software 1 2 to 1 3 NI DAQ driver software 1 3 to 1 4 register level programming 1 4 specifications analog input A 1 to A 2 amplifier characteristics A 3 dynamic characteristics A 3 to A 4 explanation A 4 to A 5 input characteristics A 1 to A 2 stability A 4 Lab PC 1200 Al User Manual Index transfer characteristics A 2 analog output A 6 to A 7 dynamic characteristics A 7 explanation A 7 output characteristics A 6 stability A 7 transfer characteristics A 6 voltage output A 7 bus interface A 9 digital I O A 8 digital trigger A 9 environment A 10 physical A 9 power requirements A 9 timing I O A 8 to A 9 square wave generation 3 26 STB signal description table 3 30 mode input timing figure 3 31 mode 2 bidirectional timing figure 3 33 switchless mode 2 3 system noise A 5 T technical support B 1 to B 2 telephone and fax support numbers B 2 theory of operation analog input 4 5 to 4 11 analog input circuitry 4 6 to 4 8 block diagram 4 6 controlled acquisition mode 4 8 data acquisition operations 4 8 to 4 10 data acquisition rates 4 10 to 4 11 freerun acquisition mode 4 9 interval scanning acquisition mode 4 9 multichannel scanned data acquisition 4 10 single channel data acquisition 4 10 Lab PC 1200 Al User Manual 1 8 analog output 4 12 to 4 13 analo
75. ne ereennernveenvenveeneenven 3 9 Ground Referenced Signal Sources nennen 3 9 Input Configurations sisii s sirrin sssini oseko risset srito e te sirib aR Eso 3 10 Differential Connection Considerations DIFF Configuration annen venne eneee oneven vennen 3 11 Differential Connections for Ground Referenced Sigal SOULCES serveer zersenrvenrnervenseniendernderdeterennendndnedediden 3 12 Differential Connections for Nonreferenced or Floating Signal SOULCES s2 sc c ssehyssevesetese ee sssshhioes eke serene eeeedb onesies 3 13 Single Ended Connection Considerations 3 14 Single Ended Connections for Floating Signal Sources RSE Configuration ennen ene venne venne ene venne 3 15 Single Ended Connections for Grounded Signal Sources NRSE Configuration nennen onee one venne onver ene 3 15 Common Mode Signal Rejection Considerations 3 16 Analog Output Signal Connections nanos oneven sense envenvennvenv eneen 3 17 Digital I O Signal Connections nonnen neons envennenneenvernvenveenen 3 18 Logical Input and Output nnen enn ennernvenveenvennen 3 19 Port C Pin Connections os sisc scsscessscscssveestecessscdecsnetessguasdusoscseasssneiccs 3 20 Power Connections msnnen ergeren ieiseenen welkde esd EEE KE xt ed lent enden ees 3 21 Data Acquisition and General Purpose Timing Signal Connections 3 21 Data Acquisition Timing Connections
76. ng sources National Instruments Corporation 3 9 Lab PC 1200 Al User Manual Chapter 3 Signal Connections Input Configurations You can configure the 1200 Series for one of three input modes RSE NRSE or DIFF The following sections discuss the use of single ended and differential measurements and considerations for measuring both floating and ground referenced signal sources Table 3 4 summarizes the recommended input configurations for both types of signal sources Table 3 4 Summary of Analog Input Connections Signal Source Type Floating Signal Sources Grounded Signal Source Not Connected to Earth Ground Examples Examples Ungrounded thermocouples Plug in instruments with Signal conditioning with isolated outputs nonisolated outputs e Battery devices Differential DIFF See text for information on bias resistors NOT RECOMMENDED Referenced Single Ended Ground RSE Ground loop losses Vg are added to measured signal Nonreferenced Single Ended NRSE AIGND See text for information on bias resistors Lab PC 1200 Al User Manual 3 10 National Instruments Corporation Chapter 3 Signal Connections Differential Connection Considerations DIFF Configuration Differential connections are those in which each 1200 Series analog input signal has its own reference signal or signal return path These connections are available when you configure t
77. nput Connections for Floating Sources The 100 KQ resistors shown in Figure 3 5 create a return path to ground for the bias currents of the instrumentation amplifier If there is no return path the instrumentation amplifier bias currents charge stray capacitances resulting in uncontrollable drift and possible saturation in the amplifier Typically values from 10 to 100 KQ are used A resistor from each input to ground as shown in Figure 3 5 provides bias current return paths for an AC coupled input signal National Instruments Corporation 3 13 Lab PC 1200 Al User Manual Chapter 3 Signal Connections Lab PC 1200 Al User Manual If the input signal is DC coupled you need only the resistor that connects the negative signal input to ground This connection does not lower the input impedance of the analog input channel Single Ended Connection Considerations Single ended connections are those in which all 1200 Series analog input signals are referenced to one common ground The input signals are tied to the positive input of the instrumentation amplifier and their common ground point is tied to the negative input of the instrumentation amplifier When you configure the 1200 Series board for single ended input NRSE or RSE eight analog input channels are available Use single ended input connections when all of the input signals meet the following conditions e Input signals are high level greater than 1 V e Leads connecting
78. ns in laboratory testing production testing and industrial process monitoring and control Organization of This Manual The Lab PC 1200 AI User Manual is organized as follows e Chapter 1 Introduction describes the 1200 Series boards lists what you need to get started software programming choices and optional equipment and explains how to build custom cables and unpack your board e Chapter 2 Installation and Configuration describes how to install and configure your 1200 Series board e Chapter 3 Signal Connections describes how to make input and output signal connections to the 1200 Series boards via the board T O connector and details the I O timing specifications e Chapter 4 Theory of Operation explains the operation of each functional unit of the 1200 Series boards e Chapter 5 Calibration discusses the calibration procedures for the 1200 Series analog I O circuitry e Appendix A Specifications lists the specifications for the 1200 Series boards e Appendix B Customer Communication contains forms you can use to request help from National Instruments or to comment on our products e The Glossary contains an alphabetical list and description of terms used in this manual including abbreviations acronyms metric prefixes mnemonics and symbols e The Index contains an alphabetical list of key terms and topics in this manual including the page where you can find each one National Instruments Corp
79. nstrumentation amplifier tied to AISENSE AIGND and not connected to ground DIFF DIFF mode provides four differential inputs with the positive input of the instrumentation amplifier tied to channels 0 2 4 or 6 and the negative input tied to channels 1 3 5 or 7 respectively thus choosing channel pairs 0 1 2 3 4 5 or 6 7 While reading the following paragraphs you may find it helpful to refer to the Analog Input Signal Connections section of Chapter 3 Signal Connections which contains diagrams showing the signal paths for the three configurations RSE Input Eight Channels Reset Condition RSE input means that all input signals are referenced to a common ground point that is also tied to the 1200 Series board analog input ground The differential amplifier negative input is tied to analog ground The RSE configuration is useful for measuring floating signal sources With this input configuration your 1200 Series board can monitor eight different analog input channels Considerations for using the RSE configuration are discussed in Chapter 3 Signal Connections Notice that in this mode the signal return path is analog ground at the connector through the AISENSE AIGND pin National Instruments Corporation 2 9 Lab PC 1200 Al User Manual Chapter 2 Installation and Configuration Lab PC 1200 Al User Manual NRSE Input Eight Channels NRSE input means that all input signals are re
80. nto or is connected to your computer Use these manuals for hardware installation and configuration instructions specification information about your DAQ hardware and application hints Software documentation Examples of software documentation you may have are the LabVIEW and LabWindows CVI documentation sets and the NI DAQ documentation After you set up your hardware system use either the application software LabVIEW or LabWindows CVI manuals or the NI DAQ documentation to help you write your application If you have a large and complicated system it is worthwhile to look through the software documentation before you configure your hardware Accessory installation guides or manuals If you are using accessory products read the terminal block and cable assembly installation guides and accessory board user manuals They explain how to physically connect the relevant pieces of the system Consult these guides when you are making your connections SCXI chassis manuals If you are using SCXI read these manuals for maintenance information on the chassis and installation instructions xi Lab PC 1200 Al User Manual About This Manual Related Documentation The following National Instruments document contains information that you may find helpful as you read this manual e Application Note 025 Field Wiring and Noise Considerations for Analog Signals The following documents also contain information that you may find helpful
81. ny code will not deviate from a straight line by more than 1 LSB A 4 National Instruments Corporation Appendix A Specifications This specification is misleading because although a particularly wide code s center may be found within 1 LSB of the ideal one of its edges may be well beyond 1 5 LSB thus the ADC would have a relative accuracy of that amount National Instruments tests its boards to ensure that they meet all three linearity specifications defined in this appendix Differential nonlinearity DNL is a measure of deviation of code widths from their theoretical value of 1 LSB The width of a given code is the size of the range of analog values that can be input to produce that code ideally 1 LSB A specification of 1 LSB differential nonlinearity ensures that no code has a width of 0 LSBs that is no missing codes and that no code width exceeds 2 LSBs System noise is the amount of noise seen by the ADC when there is no signal present at the input of the board The amount of noise that is reported directly without any analysis by the ADC is not necessarily the amount of real noise present in the system unless the noise is considerably greater than 0 5 LSB rms Noise that is less than this magnitude produces varying amounts of flicker and the amount of flicker seen is a function of how near the real mean of the noise is to a code transition If the mean is near or at a transition between codes the ADC flickers evenly
82. o 3 24 posttrigger data acquisition timing figure 3 23 pretrigger data acquisition timing figure 3 24 timing requirements figure 3 22 EXTTRIG signal data acquisition timing 3 22 to 3 24 definition table 3 5 maximum voltage input rating 3 26 posttrigger and pretrigger modes 3 22 to 3 24 pretrigger data acquisition timing figure 3 24 EXTUPDATE signal data acquisition timing with Lab PC 1200 3 25 definition table 3 5 maximum voltage input rating 3 26 Lab PC 1200 Al User Manual 1 4 waveform generation timing 3 25 to 3 26 waveform generation timing sequence figure 3 26 F fax and telephone support numbers B 2 Fax on Demand support B 2 floating signal sources differential connections 3 12 to 3 13 purpose and use 3 9 single ended connections RSE configuration 3 14 to 3 15 freerun acquisition mode 4 9 frequency measurement general purpose timing signal connections 3 27 to 3 28 illustration 3 28 FTP support B 1 G GATBO signal table 3 5 GATB1 signal table 3 6 GATB2 signal table 3 6 GATE signals general purpose timing signal connections 3 26 to 3 29 timing requirements figure 3 29 general purpose timing signal connections See also data acquisition timing connections event counting 3 26 with external switch gating figure 3 27 frequency measurement 3 27 to 3 28 GATE CLK and OUT signals 3 26 to 3 29 pins 3 21 pulse generation 3 26 pulse width measurement 3 2
83. o become a zero mean random variable rather than a deterministic function of input For more information on the effects of dither see Dither in Digital Audio by John Vanderkooy and Stanley P Lipshitz Journal of the Audio Engineering Society Vol 35 No 12 Dec 1987 The 1200 Series use a 12 bit successive approximation ADC The converter 12 bit resolution allows it to resolve its input range into 4 095 different steps The ADC has an input range of 5 V and 0 to 10 V When an A D conversion is complete the ADC clocks the result into the A D FIFO The A D FIFO is 16 bits wide and 512 words deep This FIFO serves as a buffer to the ADC The A D FIFO can collect up to 512 A D conversion values before losing any information thus allowing the software some extra time to catch up with the hardware If you store more than 512 values in the A D FIFO before reading from it an error condition called A D FIFO overflow occurs and you lose A D conversion information The output from the ADC can be interpreted as either straight binary or two s complement depending on which coding scheme you select Straight binary is the recommended coding scheme for unipolar input mode With this scheme the data from the ADC is interpreted as a 12 bit straight binary number with a range of 0 to 4 095 Two s complement is the recommended coding scheme for bipolar input mode National Instruments Corporation 4 7 Lab PC 1200 Al User Manual Chapter 4
84. ograms device names functions variables file names and extensions and for statements and comments taken from program code NI DAQ refers to the NI DAQ software for PC compatibles unless otherwise noted SCXT stands for Signal Conditioning eXtensions for Instrumentation and is a National Instruments product line designed to perform front end signal conditioning for National Instruments plug in DAQ boards Abbreviations acronyms metric prefixes mnemonics symbols and terms are listed in the Glossary X National Instruments Corporation About This Manual National Instruments Documentation The Lab PC 1200 AI User Manual is one piece of the documentation set for your DAQ system You could have any of several types of manuals depending on the hardware and software in your system Use the manuals you have as follows National Instruments Corporation Getting Started with SCXI If you are using SCXI this is the first manual you should read It gives an overview of the SCXI system and contains the most commonly needed information for the modules chassis and software Your SCXI hardware user manuals If you are using SCXI read these manuals next for detailed information about signal connections and module configuration They also explain in greater detail how the module works and contain application hints Your DAQ hardware user manuals These manuals have detailed information about the DAQ hardware that plugs i
85. om gate 400 ns maximum Figure 3 17 General Purpose Timing Signals The GATE and OUT signals in Figure 3 17 are referenced to the rising edge of the CLK signal National Instruments Corporation 3 29 Lab PC 1200 Al User Manual Chapter 3 Signal Connections Timing Specifications Use the handshaking lines STB and IBF to synchronize input transfers Use the handshaking lines OBF and ACK to synchronize output transfers Table 3 6 lists the signals used in the mode timing diagrams Table 3 6 Port C Signal Descriptions Name Type Description STB Input Strobe Input A low signal on this handshaking line loads data into the input latch IBF Output Input Buffer Full A high signal on this handshaking line indicates that data has been loaded into the input latch This is primarily an input acknowledge signal ACK Input Acknowledge Input A low signal on this handshaking line indicates that the data written from the specified port has been accepted This signal is primarily a response from the external device that it has received the data from the 1200 Series OBF Output Output Buffer Full A low signal on this handshaking line indicates that data has been written from the specified port INTR Output Interrupt Request This signal becomes high when the 82C55A is requesting service during a data transfer Set the appropriate interrupt enable signals to generate this signal RD Int
86. on Chapter 3 Signal Connections ACHO ACH2 ACH4 ACH6 AISENSE AIGND AGND DGND PA1 PA3 PA5 PA7 PB1 PB3 PB5 PB7 PC1 PC3 PC5 PC7 NC OUTBO OUTB1 CLKB1 GATB2 5V O AJN 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 ACH1 ACH3 ACH5 ACH7 NC NC PAO PA2 PA4 PAG PBO PB2 PB4 PB6 PCO PC2 PC4 PC6 EXTTRIG EXTCONV GATBO GATB1 OUTB2 CLKB2 DGND National Instruments Corporation Figure 3 2 Lab PC 1200AI 1 0 Connector Pin Assignments Lab PC 1200 Al User Manual Chapter 3 Signal Connections 1 0 Connector Signal Descriptions Table 3 1 lists the connector pins on the 1200 Series boards I O connectors by pin number and gives each signal name and signal connector pin description Table 3 1 Signal Descriptions for 1200 Series 1 0 Connector Pins Pin Signal Name Direction Reference Description 1 8 ACH lt 0 7 gt Al AGND Analog Channel 0 through 7 Analog input channels 0 through 7 Each channel pair ACH i i 1 lt i 0 6 gt can be configured as either one differential input or two single ended inputs 9 AISENSE AIGND I O AGND Analog Input Sense Analog Input Ground Connected to AGND in RSE mode analog input sense in NRSE mode 10 DACOOUT AO AGND Digital to Analog Converter 0 Output Lab
87. oration ix Lab PC 1200 Al User Manual About This Manual Conventions Used in This Manual 1200 Series bold bold italic italic monospace NI DAQ SCXI Lab PC 1200 Al User Manual The following conventions are used in this manual This icon to the left of bold italicized text denotes a note which alerts you to important information This icon to the left of bold italicized text denotes a caution which advises you of precautions to take to avoid injury data loss or a system crash This icon to the left of bold italicized text denotes a warning which advises you of precautions to take to avoid being electrically shocked The symbol indicates that the text following it applies only to a specific 1200 Series board Angle brackets containing numbers separated by an ellipses represent a range of values associated with a bit signal or port for example ACH lt 0 7 gt stands for ACHO through ACH7 1200 Series refers to both the Lab PC 1200 and Lab PC 1200AI boards unless otherwise noted Bold text denotes menus menu items or dialog box buttons or options Bold italic text denotes a note caution or warning Italic text denotes emphasis a cross reference or an introduction to a key concept Text in this font denotes text or characters that are to be literally input from the keyboard sections of code and syntax examples This font is also used for the proper names of disk drives paths directories pr
88. polar 0 to 10 V Analog Output CHI Polarity Bipolar 5 V reset condition Unipolar 0 to 10 V Analog Input Polarity Bipolar 5 V reset condition Unipolar 0 to 10 V Analog Input Mode Referenced single ended RSE reset condition Nonreferenced single ended NRSE Differential DIFF Both the analog input and analog output circuitry is software National Instruments Corporation configurable Lab PC 1200AI Upon power up or after a software reset the Lab PC 1200AI is set to the following configuration e Referenced single ended input mode e 5 V analog input range bipolar 2 7 Lab PC 1200 Al User Manual Chapter 2 Installation and Configuration Table 2 4 lists the available analog input configurations for the Lab PC 1200AI and shows the configuration in reset condition Table 2 4 Analog Input Settings Lab PC 1200AI Parameter Configuration Analog Input Bipolar 5 V reset condition Polarity Unipolar 0 to 10 V Analog Input Referenced single ended RSE reset condition Mode Nonreferenced single ended NRSE Differential DIFF The analog input circuitry is completely software configurable Analog Output Polarity _Lab PC 1200 The Lab PC 1200 has two analog output channels at the I O connector You can configure each analog output channel for either unipolar or bipolar output A unipolar configuration has a range of 0 to 10 V at the an
89. poration Appendix A Specifications Digital logic levels Level Min Max Input low voltage 0 3 V 0 8 V Input high voltage 2 2V 5 3 V Output low voltage E our 2 1 mA 0 45 V Output high voltage T Ee our 0 92 mA 3 7 V Protection re Data transfer ennen Digital Trigger Compatibility ne RESPONSE evernrest enne veevseneierdan see Be derdes Pulse Width anene Bus Interface Power Requirement Power consumption Lab PC 1200 Lab PC 1200AI eeen Power available at I O connector Physical Dimensions sirenenet ntan en i T O connector renee National Instruments Corporation A 9 0 5 to 5 5 V powered on 0 5 V powered off Interrupts programmed I O Rising edge 50 ns min 185 mA at 5 VDC 45 150 mA at 5 VDC 45 4 65 to 5 25 V fused at 1 A 17 45 by 10 56 cm 6 87 by 4 16 in 50 pin male Lab PC 1200 Al User Manual Appendix A Specifications Environment Operating temperature eseeeeeeeee e 0 to 50 C Storage temperature eee 55 to 150 C Relative humidity cee 5 to 90 noncondensing Lab PC 1200 Al User Manual A 10 National Instruments Corporation Customer Communication For your convenience this appendix contains forms to help you gather the information necessary to help us solve your technical problems and a form you ca
90. r Data Acquisition Timing ann unseenveenvenven neen vennen 3 23 Figure 3 12 Pretrigger Data Acquisition Timing neven vennen envenneenvenvenn 3 24 Figure 3 13 Interval Scanning Signal Timing unne nnnvenvenneenvenneenvenvenneene 3 25 Figure 3 14 EXTUPDATE Signal Timing for Updating DAC Output 3 26 Figure 3 15 Event Counting Application with External Switch Gating 3 27 Figure 3 16 Frequency Measurement Application naan ce en ven vennvenn 3 28 Figure 3 17 General Purpose Timing Signals nennen erven vennen eneen 3 29 Figure 3 18 Mode 1 Timing Specifications for Input Transfers 3 31 Figure 3 19 Mode 1 Timing Specifications for Output Transfers 3 32 Figure 3 20 Mode 2 Timing Specification for Bidirectional Transfers 3 33 Figure 4 1 Lab PC 1200 Block Diagram naan ennen seen enve eneen vennen 4 1 Figure 4 2 __Lab PC 1200AI Block Diagram annen ornoo venvenve ensen erven 4 2 Figure 4 3 PE Interface Circuitry oeiee ispir riei eer rE a eene vaandel 4 3 Figure 4 4 1200 Series Timing Circuitry neee venveeneenvenvennvenv eneen 4 4 Figure 4 5 1200 Series Analog Input Circuitry annae oneven ensen 4 6 Figure 4 6 Lab PC 1200 Analog Output Circuitry eneen 4 12 Figure 4 7 Digital I O Circuitry eee reseo erte rossii ioti essiri 4 13 Tables Table 2 1 PC AT I O Address Map neer en verve envenveenvenvennvenn 2 4 Table 2
91. r Manual amperes analog channel 0 through 7 signals acknowledge input signal analog to digital analog to digital converter an electronic device often an integrated circuit that converts an analog voltage to a digital number analog ground signal analog input analog input sense analog input ground signal American National Standards Institute analog output available bulletin board system bisynchronous Celsius channel counter B1 B2 clock signals centimeters counter interrupt signal G 2 National Instruments Corporation CONV CTR D A DAC DAC OUTPUT UPDATE DACOOUT DAC1OUT DACWRT DAQ DAQD A DATA dB DC DGND DI DIFF DIO DMA DMATC DNL DO National Instruments Corporation G 3 Glossary conversion counter digital to analog digital to analog converter an electronic device often an integrated circuit that converts a digital number into a corresponding analog voltage or current DAC output update signal digital to analog converter 0 1 output signals DAC write signal data acquisition a system that uses the computer to collect receive and generate electrical signals data acquisition board data address line signal data lines at the specified port signal decibels direct current digital ground signal digital input differential digital input output direct memory access direct memory access terminal count differential nonlinearity digital output
92. r the rest of the scan interval after the desired channels have been scanned Refer to the Interval Scanning Acquisition Mode section in Chapter 4 Theory of Operation for more information on interval scanning Lab PC 1200 Al User Manual 3 24 National Instruments Corporation Chapter 3 Signal Connections gt id tm 50ns OUTB1 _ lt tm 50 ns E RR RR ER a is Lf CONVERT GATE ADC CH CH1 cro CH1 CHO Figure 3 13 Interval Scanning Signal Timing Lab PC 1200 National Instruments Corporation Only the Lab PC 1200 uses the EXTUPDATE signal It externally controls updating the output voltage of the 12 bit DACs and or generates an externally timed interrupt There are two update modes immediate update and delayed update In immediate update mode the analog output is updated as soon as a value is written to the DAC If you select the delayed update mode a value is written to the DAC however the corresponding DAC voltage is not updated until a low level on the EXTUPDATE signal is sensed Furthermore if you enable interrupt generation an interrupt is generated whenever a rising edge is detected on the EXTUPDATE bit Therefore you can perform externally timed interrupt driven waveform generation on the Lab PC 1200 The EXTUPDATE line is susceptible to noise caused by switching lines and could generate false interrupts The width of the EXTUPDATE pulse
93. rating N Caution Exceeding the input signal range even on unused analog input channels distorts input signals Exceeding the maximum input voltage rating can damage the 1200 Series board and the computer National Instruments is Nor liable for any damages resulting from such signal connections Table 3 2 Bipolar Analog Input Signal Range Versus Gain Gain Setting Input Signal Range 5 0 to 4 99756 V 2 2 5 to 2 49878 V 5 1 0 to 0 99951 V 10 500 to 499 756 mV 20 250 to 249 877 mV 50 100 to 99 951 mV 100 50 to 49 975 mV Table 3 3 Unipolar Analog Input Signal Range Versus Gain Gain Setting Input Signal Range 1 0 to 9 99756 V 2 0 to 4 99878 V 5 0 to 1 99951 V 10 0 to 999 756 mV 20 0 to 499 877 mV 3 7 Lab PC 1200 Al User Manual National Instruments Corporation Chapter 3 Signal Connections Lab PC 1200 Al User Manual Table 3 3 Unipolar Analog Input Signal Range Versus Gain Continued Gain Setting Input Signal Range 50 0 to 199 951 mV 100 0 to 99 975 mV How you connect analog input signals to your 1200 Series board depends on how you configure the board s analog input circuitry and the type of input signal source With different board configurations you can use the 1200 Series instrumentation amplifier in different ways Figure 3 3 shows a diagram of the 1200 Series instrumentation amplifier
94. ration of each functional unit of the 1200 Series boards Functional Overview The block diagrams in Figures 4 1 and 4 2 show the functional overviews of the 1200 Series boards gt Dither Address Address 16 3 ed ___2 p gt 4 4 12 Bit Program t Input 17 FIFO A D Gain Mux Data Digital 4 lt gt igita 8 E 5 p gt Calibration Control ogic 2 A 2 4 ita a 12 Bit 5 S DMA Interrupt 82C53 82C55A gt D A 8 O Counter Time Digital 72 Q A Group A Interface Po Bit 8 x p 12 2 T Interrupt gt D A Z aT Ee 82053 Timebase 8 Counter Timer gt Group B Time 2 MHz 10 MHz os h Oscillator Divider Timebase National Instruments Corporation Figure 4 1 Lab PC 1200 Block Diagram 4 1 Lab PC 1200 Al User Manual Chapter 4 Theory of Operation Address 17 Data 8 Control PC I O Channel Interrupt 1 Address gt Dither ag 4 12 Bit 4 Program lt Input 8 AFO A D Gain Pa Mux e 4 Digital 4 p 4 4 Ta 3 p gt Calibration 5 82C55A 24 D Digital EL gt Interface S Q gt 82053 Tenebra 8 Counter Timerld Lp gt Group B Time 2 MHz 10
95. re Notice that the sample counter has been programmed to allow five conversions after the rising edge on the EXTTRIG signal Additional transitions on the EXTTRIG line have no effect until you initiate a new data acquisition sequence National Instruments Corporation 3 23 Lab PC 1200 Al User Manual Chapter 3 Signal Connections EXTTRIG 4 Z tm ze tm 90 ns min RR RR RR RRRS CONVERT f f t j f Figure 3 12 Pretrigger Data Acquisition Timing Because both pretrigger and posttrigger modes use EXTTRIG input you can only use one mode at a time For interval scanning data acquisition counter B1 determines the scan interval Instead of using counter B1 you can externally time the scan interval through OUTB1 If you externally time the sample interval you should also externally time the scan interval Figure 3 13 shows an example of an interval scanning data acquisition operation The scan interval and the sample interval are being timed externally through OUTB1 and EXTCONV Channels 1 and 0 of the input multiplexers are being scanned once during each scan interval The first rising edge of EXTCONV must occur a minimum of 50 ns after the rising edge on OUTBI The first rising edge of EXTCONV after the rising edge of OUTB1 enables an internal GATE signal that allows conversions to occur The first conversion then occurs on the following falling edge of EXTCONV The GATE signal disables conversions fo
96. re Configuration anneer eenvenneenveenvenveenvenveenvenvennvenvennvenvernveneeenvenven 2 2 Bus Related Configuration nennen enn ennvenvennerseenserseenseenveenvenvenven 2 2 Plug and Play Mode te ze st dorsen deonwee en vicones den erenet nas aa ai 2 2 Switchless MOde sassen senden E i EAN EATE 2 3 Base I O Address Selection annen 2 3 DMA Channel Selection nnen eneen 2 3 Interrupt Channel Selection nennen eneen 2 3 Data Acquisition Related Configuration eenen vennen ennvennenneene 2 7 Analog I O Configuration nnen eneen vennvenvennveneennen 2 7 Analog Output Polarity nnen neen eenvenvenneeneeeneenven 2 8 Analog Input Polarity annen neons enneenvenvennveneerseenenn 2 8 Analog Input Mode 5500 tersersscetoronveren er roiroi iesise tita so iieis 2 9 RSE Input Eight Channels Reset Condition 2 9 NRSE Input Eight Channels eenen 2 10 DIFF Input Four Channels oneven oneven en 2 10 National Instruments Corporation Vv Lab PC 1200 Al User Manual Contents Chapter 3 Signal Connections VO Connector es Bh antenne neren T Gi ten bach nash E EES E Rr R EE a Reese wes 3 1 T O Connector Signal Descriptions avan onser erneenevenverveenvennen 3 4 Analog Input Signal Connections nanne ene orneeneerneeneeenvenveenvennen 3 6 Types of Signal Sources anar annerne ene erneenneenveenvenveeneenven 3 9 Floating Signal Sources avan ennerne e
97. res 3 1 and 3 2 show the pin assignments for the 1200 Series board I O connectors J Caution Connections that exceed any of the maximum ratings of input or output signals on the 1200 Series boards can damage your board and the computer This includes connecting any power signals to ground and vice versa You should not externally drive digital I O lines while the computer is powered off doing so can cause damage to the computer National Instruments is not liable for any damages resulting from signal connections that exceed these maximum ratings National Instruments Corporation 3 1 Lab PC 1200 Al User Manual Chapter 3 Signal Connections Lab PC 1200 Al User Manual ACHO ACH2 ACH4 ACH6 AISENSE AIGND AGND DGND PA1 PA3 PA5 PA7 PB1 PB3 PB5 PB7 PC1 PC3 PC5 PC7 EXTUPDATE OUTBO OUTB1 CLKB1 GATB2 5V O AJN Ni cn oo 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 ACH1 ACH3 ACH5 ACH7 DACOOUT DAC1OUT PAO PA2 PA4 PA6 PBO PB2 PB4 PB6 PCO PC2 PC4 PC6 EXTTRIG EXTCONV GATBO GATB1 OUTB2 CLKB2 DGND Figure 3 1 Lab PC 1200 I O Connector Pin Assignments 3 2 National Instruments Corporati
98. ries boards generate an interrupt in the following cases each of these interrupts is individually enabled and cleared Timing When a single A D conversion can be read from the A D FIFO memory When the A D FIFO is half full When a data acquisition operation completes including when either an OVERFLOW or an OVERRUN error occurs When the digital I O circuitry generates an interrupt When a DMA terminal count pulse is received The Lab PC 1200 can also generate an interrupt when a rising edge signal is detected on the DAC update signal The 1200 Series boards use two 82C53 counter timer integrated circuits for internal data acquisition timing and for general purpose I O timing functions National Instruments Corporation 4 3 Lab PC 1200 Al User Manual Chapter 4 Theory of Operation They are also used for analog output timing if you have a Lab PC 1200 Figure 4 4 shows a block diagram of both groups of timing circuitry counter groups A and B GATEB2 CLKB2 General lt lt GATEB2 Purpose Pi Counter ae gt OUTBO OUTB2 Oe 1 MHz Source GATEB1 GATEB1 CLKB1 MUX Scan MUX Interval General Purpose CLKB1 Counter CLKAO CTR RD OUTB1 OUTB1 Digital CTR WRT OUTBO gt OUTBO Control ATEB GATEBO Logic Data G 0 a 8 Timebase Extension General Purpose CLKAO 4 Counter 2 MHz GATEAO CLKBO Source Sample 82C53 Counter Timer Interval
99. round but has an isolated ground reference point Some examples of floating signal sources are transformer outputs thermocouples battery powered devices optical isolator outputs and isolation amplifiers Tie the ground reference of a floating signal to the 1200 Series board analog input ground to establish a local or onboard reference for the signal Otherwise the measured input signal varies or appears to float An instrument or device that supplies an isolated output falls into the floating signal source category Ground Referenced Signal Sources A ground referenced signal source connects in some way to earth ground and is therefore already connected to acommon ground point with respect to the 1200 Series board if the computer is plugged into the same power supply Nonisolated outputs of instruments and devices that plug into the power supply fall into this category The difference in ground potential between two instruments connected to the same power supply is typically between 1 and 100 mV but can be much higher if power distribution circuits are not properly connected The connection instructions that follow for grounded signal sources eliminate this ground potential difference from the measured signal x Note If you power both the 1200 Series board and your computer with a floating power source such as a battery your system may be floating with respect to earth ground In this case treat all of your signal sources as floati
100. s case code width is the difference between the analog values produced by consecutive digital codes A specification of 1 LSB differential nonlinearity ensures that the code width is always greater than 0 LSBs guaranteeing monotonicity and is always less than 2 LSBs National Instruments Corporation A 7 Lab PC 1200 Al User Manual Appendix A Specifications Timing 1 0 Lab PC 1200 Al User Manual Digital 1 0 Number of channels 0 0 0 24 I O three 8 bit ports uses the 82C55A PPI Compatibility ane TTL Digital logic levels Level Min Max Input low voltage 0 3 V 0 8 V Input high voltage 2 2V 5 3 V Output low voltage our 2 5 mA 0 4 V Output high voltage nr our 40 pA 4 2 V our 2 5 mA 3 7 V Power on state neee All ports mode 0 input Protection geri orenen 0 5 V to 5 5 V powered on 0 5 V powered off Data transfers eee Interrupts programmed I O Number of channels 0 0 0 0 3 counter timers Protec oirrese s 0 5 V to 5 5 V powered on 0 5 V powered off Resolution Counter timers 16 bits Compatibility ne TTL Base clock available 2 MHz Base clock accuracy eee eee 50 ppm max Max source frequency ee 8 MHz Min source pulse duration 125 ns Min gate pulse duration 50 ns A 8 National Instruments Cor
101. s that the signal is active low DI Digital Input DIO Digital Input Output NC Not Connected DO Digital Output N A Not Applicable The connector pins are grouped into analog input signal pins analog output signal pins digital I O signal pins timing I O signal pins and power connections The following sections describe the signal connection guidelines for each of these groups Analog Input Signal Connections Lab PC 1200 Al User Manual Pins through 8 are analog input signal pins for your 1200 Series board 12 bit ADC Pin 9 AISENSE AIGND is an analog common signal You can use this pin for a general analog power ground tie to the 1200 Series board in RSE mode or as a return path in NRSE mode Pin 11 AGND is the bias current return point for differential measurements Pins through 8 are tied to the eight single ended analog input channels of the input multiplexer through 4 7 kQ series resistors Pins 2 4 6 and 8 are also tied to an input multiplexer for DIFF mode 3 6 National Instruments Corporation Chapter 3 Signal Connections The signal ranges for inputs ACH lt 0 7 gt at all possible gains are shown in Tables 3 2 and 3 3 Exceeding the input signal range will not damage the input circuitry as long as you don t exceed the maximum powered on input voltage rating of 35 V or the powered off voltage rating of 25 V The 1200 Series board is guaranteed to withstand inputs up to the maximum input voltage
102. should therefore be as short as possible but greater than 50 ns Figure 3 14 illustrates a waveform generation timing sequence using the EXTUPDATE signal and the delayed update mode The DACs are updated by a high level on the DAC OUTPUT UPDATE signal which in this case is triggered by a low level on the EXTUPDATE line The CNTINT signal interrupts the computer The rising edge of EXTUPDATE generates this interrupt DACWRT is the signal that writes a new value to the DAC 3 25 Lab PC 1200 Al User Manual Chapter 3 Signal Connections EXTUPDATE DAC OUTPUT UPDATE DACWRT CNTINT J tm 50 ns min Lab PC 1200 Al User Manual Figure 3 14 EXTUPDATE Signal Timing for Updating DAC Output The absolute maximum voltage input rating for the EXTCONV EXTTRIG OUTB1 and EXTUPDATE signals is 0 5 to 5 5 V with respect to DGND For more information concerning the various modes of data acquisition and analog output refer to your NI DAQ documentation or to Chapter 4 Theory of Operation in this manual General Purpose Timing Signal Connections The general purpose timing signals include the GATE CLK and OUT signals for the three 82C53 B counters The 82C53 counter timers can be used for the 1200 Series board general purpose applications such as pulse and square wave generation event counting and pulse width time lapse and frequency measurement For these applications th
103. struments Corporation A 1 Eight single ended eight pseudodifferential or four differential software selectable Successive approximation 12 bits 1 in 4 096 100 kS s single channel Lab PC 1200 Al User Manual Appendix A Specifications Lab PC 1200 Al User Manual Max working voltage signal common mode Overvoltage protection Inputs protected eee FIFO buffer size eeeeeeeeeeere ener Data transfers ne Dithe tis inene sorene reni Transfer Characteristics Relative accuracy DNL oo ao taonseeneret ooo inebeenendittenetd No missing codes ne Offset error Pregain error after calibration Pregain error before calibration Postgain error after calibration In differential or NRSE mode the negative input AISENSE should remain within 5 V bipolar input range or 5 to 2 V unipolar input range of AGND The positive input should remain within 5 V to 10 V of AGND 35 V powered on 25 V powered off ACH lt 0 7 gt 512 Samples DMA interrupts programmed I O Available 0 5 LSB typ dithered 1 5 LSB max undithered 1 LSB max 12 bits guaranteed 10 uV max 20 mV max 1 mV max Postgain error before calibration 200 mV max Gain error relative to calibration reference After calibration Before calibration A
104. ta bits 1 stop bit no parity FTP Support To access our FTP site log on to our Internet host ftp natinst com aS anonymous and use your Internet address such as joesmith anywhere com as your password The support files and documents are located in the support directories National Instruments Corporation B 1 Lab PC 1200 Al User Manual Fax on Demand Support Fax on Demand is a 24 hour information retrieval system containing a library of documents on a wide range of technical information You can access Fax on Demand from a touch tone telephone at 512 418 1111 E Mail Support Currently USA Only You can submit technical support questions to the applications engineering team through e mail at the Internet address listed below Remember to include your name address and phone number so we can contact you with solutions and suggestions support natinst com Telephone and Fax Support National Instruments has branch offices all over the world Use the list below to find the technical support number for your country If there is no National Instruments office in your country contact the source from which you purchased your software to obtain support Country Australia Austria Belgium Brazil Canada Ontario Canada Qu bec Denmark Finland France Germany Hong Kong Israel Italy Japan Korea Mexico Netherlands Norway Singapore Spain Sweden Switzerland Taiwan United Kingdom United States Lab PC 1200
105. table 3 6 Lab PC 1200 Al User Manual 1 6 P PA lt 0 7 gt signal table 3 5 PB lt 0 7 gt signal table 3 5 PC lt 0 7 gt signal table 3 5 PC I O channel interface circuitry 4 2 to 4 3 physical specifications A 9 Plug and Play mode 2 2 polarity analog input polarity 2 8 analog output polarity 2 8 Port C signal assignments table 3 21 POSTTRIG mode 3 22 posttrigger data acquisition timing figure 3 23 power connections 3 21 power requirement specifications A 9 PRETRIG mode 3 23 pretrigger data acquisition timing figure 3 24 programmable gain amplifier 4 7 pulse generation 3 26 pulse width measurement 3 27 R RD signal description table 3 30 mode input timing figure 3 31 mode 2 bidirectional timing figure 3 33 referenced single ended mode See RSE input register level programming 1 4 relative accuracy analog input A 4 analog output A 7 RSE input configuration 2 9 definition table 2 9 single ended connections for floating signal sources 3 14 to 3 15 summary of input configurations table 3 10 National Instruments Corporation S sample counter 3 22 sample interval counter 3 22 signal connections analog input signal connections common mode signal rejection 3 16 to 3 17 differential connections 3 11 to 3 13 floating signal sources 3 12 to 3 13 ground referenced signal sources 3 11 to 3 12 overview 3 11 single ended connections 3 14 exceeding
106. three counters Counter 0 on the 82C53 A counter timer referred to as AO is a sample interval counter in timed A D conversions Counter on the 82C53 A counter timer referred to as Al is a sample counter in controlled A D conversions Therefore counter Al stops data acquisition after a predefined number of samples These counters are not available for general use Instead of counter AO you can use EXTCONV to externally time conversions Figure 3 10 shows the timing requirements for the EXTCONV input An A D conversion is initiated by a falling edge on EXTCONV EXTCONV can also be configured as an output and used as a strobe signal for SCXI through NI DAQ or LabVIEW A th tm250nsmin EXTCONV j 4 5 ta i P A D Conversion starts within 125 ns from this point Figure 3 10 EXTCONV Signal Timing The external control signal EXTTRIG can either start a data acquisition sequence or terminate an ongoing data acquisition sequence depending on the mode posttrigger POSTTRIG or pretrigger PRETRIG These modes are software selectable In the POSTTRIG mode EXTTRIG serves as an external trigger that initiates a data acquisition sequence When you use counter AO to time sample intervals a rising edge on EXTTRIG starts counter AO and the data acquisition sequence When you use EXTCONV to time sample intervals the data acquisition starts on a rising edge of EXTTRIG followed by a rising edge on EXTCONV The first
107. to 10 V of AGND Analog Output Signal Connections Lab PC 1200 Pins 10 through 12 on the I O connector are analog output signal pins Pins 10 and 12 are the DACOOUT and DACIOUT signal pins DACOOUT is the voltage output signal for analog output channel 0 DACIOUT is the voltage output signal for analog output channel 1 Pin 11 AGND is the ground reference point for both analog output channels as well as analog input The following output ranges are available Bipolar output 5 V Unipolar output Oto 10 V Maximum load current 2 mA for 12 bit linearity National Instruments Corporation 3 17 Lab PC 1200 Al User Manual Chapter 3 Signal Connections Figure 3 8 shows how to make analog output signal connections 10 DACOOUT Analog Output Load VOUT 0 Load VOUT 1 Channel 0 12 DAC1 T F on Analog Output I O Connector Channel 1 Lab PC 1200 Board Figure 3 8 Analog Output Signal Connections Digital 1 0 Signal Connections Lab PC 1200 Al User Manual Pins 13 through 37 of the I O connector are digital I O signal pins Digital T O on the 1200 Series boards uses the 82C55A integrated circuit The 82C55A is a general purpose peripheral interface containing 24 programmable I O pins These pins represent the three 8 bit ports PA PB and PC of the 82C55A Pins 14 through 21 are connected to the digital lines PA lt 0
108. trol fi BEE Control CONV Logic DMA _ Chip lake AVAIL lt q 4 Data 3 DMA _ a 8 Interrupt lt gt g WRT RD 1 3 E Gain Select l G Mux Counter nterrupt O oO gt amp mal i 2 gt Mux 8 Dither gt Dither Circuitry Dither Enable DAQ 4 Counter Timer External Trigger Timing Signals External Scan Interval Figure 4 5 1200 Series Analog Input Circuitry Analog Input Circuitry Lab PC 1200 Al User Manual The analog input circuitry consists of two analog input multiplexers muxes mux counter gain select circuitry a software programmable gain amplifier a 12 bit ADC and a 16 bit sign extended FIFO memory One of the input muxes has eight analog input channels channels 0 through 7 The other mux is connected to channels 1 3 5 and 7 for differential mode The input muxes provide input overvoltage protection of 35 V powered on and 25 V powered off The mux counters control the input muxes The 1200 Series can perform either single channel data acquisition or multichannel scanned data acquisition These two modes are software selectable For single channel data acquisition you select the channel and gain before data acquisition starts These gain and mux settings remain constant during the entire data acquisition process For multichannel scanned data acquisition you select the highest numbered channel and gain before data acquisition starts Then the mux counter decrements from the highest
109. ue or call the office nearest you Custom Cabling National Instruments offers cables and accessories for you to prototype your application or to use if you frequently change board interconnections If you want to develop your own cable however the following guidelines may be useful e For the analog input signals shielded twisted pair wires for each analog input pair yield the best results if you use differential inputs Tie the shield for each signal pair to the ground reference at the source e Route the analog lines separately from the digital lines e When using a cable shield use separate shields for the analog and digital halves of the cable Failure to do so results in noise coupling into the analog signals from transient digital signals The mating connector for the Lab PC 1200 AI is a 50 position polarized ribbon socket connector with strain relief National Instruments uses a polarized keyed connector to prevent inadvertent upside down connection to the Lab PC 1200 AI Recommended manufacturer part numbers for this mating connector are as follows e Electronic Products Division 3M part number 3425 7650 e T amp B Ansley Corporation part number 609 5041CE National Instruments Corporation 1 5 Lab PC 1200 Al User Manual Installation and Configuration This chapter describes how to install and configure your 1200 Series board Software Installation If you are using NI DAQ refer to your NI DAQ rele
110. ure of the linearity of an ADC However relative accuracy is a tighter specification than a nonlinearity specification Relative accuracy indicates the maximum deviation from a straight line for the analog input to digital output transfer curve If an ADC has been calibrated perfectly this straight line is the ideal transfer function and the relative accuracy specification indicates the worst deviation from the ideal that the ADC permits A relative accuracy specification of 1 LSB is roughly equivalent to but not the same as a 0 5 LSB nonlinearity or integral nonlinearity specification because relative accuracy encompasses both nonlinearity and variable quantization uncertainty a quantity often mistakenly assumed to be exactly 0 5 LSB Although quantization uncertainty is ideally 0 5 LSB it can be different for each possible digital code and is actually the analog width of each code Thus it is more specific to use relative accuracy as a measure of linearity than it is to use what is normally called nonlinearity because relative accuracy ensures that the sum of quantization uncertainty and A D conversion error does not exceed a given amount Integral nonlinearity INL in an ADC is an often ill defined specification that is supposed to indicate a converter s overall A D transfer linearity The manufacturer of the ADC chip National Instruments uses on the PCI 1200 specifies its integral nonlinearity by stating that the analog center of a
111. y an accurate voltage reference to another input channel for gain calibration Lab PC 1200 To calibrate the analog output section the DACO and DAC1 outputs must be wrapped back and applied to two other analog input channels To calibrate the analog input on your 1200 Series boards first configure the ADC for RSE mode and for the correct polarity at which you want to perform data acquisition Lab PC 1200 To calibrate the analog output first configure the analog input circuitry for RSE and for bipolar polarity then configure the analog output circuitry for the polarity at which you want to perform output waveform generation Refer to the NI DAQ Function Reference Manual for PC Compatibles or the NI DAQ Function Reference Online Help for more details on the Calibrate_1200 function National Instruments Corporation 5 3 Lab PC 1200 Al User Manual Specifications This appendix lists the specifications for the 1200 Series boards These specifications are typical at 25 C unless otherwise stated Analog Input Input Characteristics Number of channels Type OL ADG onverdroten Resolution neren ennen Max sampling rate Input signal ranges Board Range Board Gain Software Selectable Software Selectable 5 V 0 to 10 V 1 5 V Oto 10 V 2 22 5 V Oto5 V 5 1V 0to2 V 10 500 mV Otol V 20 250 mV 0 to 500 mV 50 100 mV 0 to 200 mV 100 50 mV 0 to 100 mV Input coupling nennen DC National In

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