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AMUX-64T User Manual - National Instruments

1. Es MoO 08199 6 INOS 15 O v DA 9 LO Osy Z 68501 ad 95 652693 o4 8 19 k 9 jo AS ojo 6 3 16 6 8899998 5 689 108503 6 UF 22259 ule 585 168204 CS E da 55555 0550000 9099008 9 R Wg 90000000 oo PILIH 10 essw Colo 5550 2 SEES o0000000L quem m puer 1 Q 0000000000000000000000000 CH m DEM p TEMPlIS 6 1 1 TN VECES E o OOOO UO OOOO AISENSE 696 OIA SAAISENsE n 0000000000000090 lt 5 5 AIGNDIZ TE Ot D o Res o o 1 5 33 29 96965 553 5 5695 9 cea O 6 195 CO 7 o Seago 6846 E oou 6 o sez o 4729
2. of the MIO board AMUX 64T Signals Sent to Input Signals Signal Conditioning Area MIO Board AIGND Jumper W1 Y 04 Temperature Sensor CHO GND CH1 CH2 Xo CH3 So CH4 CH5 So CH6 co CH7 CH28 CH29 H CH30 oo CH31 Jumper W1 ees AMUX 64T CH32 833 CH34 CH35 co CH36 6837 So CH38 CH39 CH60 e CH61 CH62 pe 1 ACH15 CH63 AISENSE AISENSE Screw Terminals J1 J2 and J42 Connectors on AMUX 64T on AMUX 64T Figure 3 1 AMUX 64T Signal Routing AMUX 64T User Manual 3 4 National Instruments Corporation Chapter 3 Signal Connections Differential Connections On the AMUX 64T channels 0 through 31 are connected to channels 0 through 7 of the MIO board AMUX 64T channels 32 through 63 are connected to channels 8 through 15 of the MIO board If the MIO board is configured for differential mode the AMUX 64T input channels are automatically used in differential mode The input screw terminals on the AMUX 64T are grouped together such that for differential mode all input signals SIG and the corresponding signal return path SIG input appear directly next to each other For example signal return path
3. 50 Ribbon Cable Daisy Chaining rack mount kit or ET Cable External 45 V anywhere else MIO Board o 0 9 16 single ended 9 9 T9 9 8 differential analog input channels Total of 64 single ended per board AISENSE Cascade to four AMUX 64T boards for a total of 256 single ended 128 differential analog input channels Figure 2 2 Daisy Chaining Multiple AMUX 64T Boards Table 2 6 lists the valid multiple board configurations for both single ended and differential modes Table 2 6 Channel Ranges for Multiple AMUX 64T Boards Number of External Channel Range Channel Range Multiplexer Boards Single Ended Differential 1 64 32 2 128 64 4 256 128 When you connect two or more AMUX 64T boards together the multiplexers on different boards must be enabled at different times Therefore each board is assigned a different channel address range determined by the configuration of switch U12 The switch settings for each board configuration are given in the following sections AMUX 64T User Manual 2 8 National Instruments Corporation Chapter 2 Configuration and Installation Single Board Configuration The AMUX 64T is shipped from the factory
4. Cold Junction Sensor Jumper selectable on differential channel 0 Output eed 10 mV C ACCUFACy serre 1 0 C from 0 to 110 C Power Requirement From computer through MIO board or external power VDC ES deridet 150 mA typ Physical Dimensions erre 12 75 by 3 80 in 32 43 by 9 65 cm connector esee Two 50 pin male ribbon cable connectors one 68 pin male shielded or ribbon cable connector 78 screw terminals National Instruments Corporation A 3 AMUX 64T User Manual Appendix A Specifications Environment Operating temperature 0 to 70 Storage 55 to 150 C Relative humidity esses 596 to 9096 noncondensing AMUX 64T User Manual A 4 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 can 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
5. eee 5 4 Table 5 2 Multiple AMUX 64T Board Addressing esses 5 5 Table 5 3 AMUX 64T Scanning Order for Each MIO Board Input Channel 5 10 AMUX 64T User Manual viii National Instruments Corporation About This Manual This manual describes the mechanical and electrical aspects of the AMUX 64T and contains information about configuring operating and programming the AMUX 64T The AMUX 64T is a front end analog multiplexer that quadruples the number of analog input signals that can be digitized with a National Instruments MIO board except the AT MIO 64 The AMUX 64T also has an integrated circuit temperature sensor that can be connected as a differential input to two of the 64 input channels jumper selectable for low cost thermocouple cold junction compensation The AMUX 64T also has signal conditioning positions available for all 64 input channels Organization of This Manual The AMUX 64T User Manual is organized as follows National Instruments Corporation Chapter 1 Introduction describes the AMUX 64T lists what you need to get started with your AMUX 64T describes the software programming choices and optional equipment and explains how to unpack your AMUX 64T Chapter 2 Configuration and Installation describes the configuration and installation of your AMUX 64T The topics discussed include switch and jumper configuration connection of the AMUX 64T board to the
6. National Instruments Corporation 5 1 AMUX 64T User Manual Chapter 5 Theory of Operation and Register Level Programming IC Temperature Sensor Jumper W1 Multiplexers CHO Fie CH1 6 o CH2 So 16 Analog Inputs CH3 4 Signal __ MUX Address DOA 5 5 5 Conditioning and Enables 3 0 8 8 8 Area Scanning E E e e Counter 15 g E CH60 Dus dd Lines o H o 6 di e CH62 B s CH63 6 o DIP Switch 64 Analog Inputs V 9 Switch 15V 5V Power Converter A A 15V LED External S 5 V To MIO board gt To Second AMUX 64T Optional AMUX 64T User Manual Figure 5 1 AMUX 64T Block Diagram The AMUX 64T multiplexers are controlled by a 4 bit scanning counter that is loaded via the 4 bit digital I O port A of the MIO board The MIO signal EXTSTROBE loads the value at digital I O port A into the AMUX 64T scanning counter The MIO signal SCANCLK which is active during scanned data acquisition switches the input channels automatically on the AMUX 64T after each A D conversion 5 2 National Instruments Corporation Chapter 5 Theory of Operation and Register Level Programming The DIP switch attached to the scanning
7. 8 6 8 JEUOI E y Table 3 3 NIST Polynomial Coefficients Type E E J J T T Temp 200 C to 0 C 0 C to 1 000 C 210 C to 0 C 0 C to 760 C 200 C to 0 C 0 C to 400 C Range 0 0 3 C to 0 01 C 0 02 C 0 0 3 C to 0 05 C 0 04 0 04 to 0 02 0 03 C Co 0 0000000 0 0000000 0 000000 0 000000 0 0000000 0 000000 1 1 6977288 2 1 7057035E 2 1 9528268E 2 1 978425E 2 2 5949 192E 2 2 592800E 2 C2 4 3514970E 7 2 3301759E 7 1 2286185E 6 2 001204E 7 2 1316967E 7 7 602961E 7 1 5859697E 10 6 5435585E 12 1 0752178E 9 1 036969E 11 7 9018692E 1 0 4 637791 11 C4 9 2502871E 14 7 3562749 17 5 9086933E 13 2 549687E 16 4 2527777E 13 2 165394E 15 C5 2 6084314E 17 1 7896001E 21 1 7256713E 16 3 585153E 21 1 3304473E 16 6 048144E 20 C6 4 1360199E 21 8 4036165E 26 2 8131513E 20 5 344285E 26 2 0241446E 20 7 293422 25 3 4034030E 25 1 3735879E 30 2 3963370E 24 5 099890E 31 1 2668171E 24 Cg 1 1564890E 29 1 0629823E 35 8 3823321E 29 Co 3 2447087 41 R R S S K K 50 C to 250 C 250 C to 1 200 C 50 C to 250 C 250 C to 1 200 C 200 C to 0 C 0 C to 500 C 0 02 C 0 005 C
8. 3 9 2159 661849 Hi H P eem S 96 06 9 e 3636 ov RS cueo S 51 5 o 618516 o g53O rj cues CER lo oa Hes E PCM B gt oj amp jo lom A 9 ol O RSSO S 69192 91 2 18536 o S o 219553 6 618376 683029 29 5 9 58 0 e 9 om cHe O 296 6 o O Re O CHa NATIONAL Ona 686860 415 6 od ol 085 exc m 6 586 518645 ul Sz AIGND x IGND AISENSE O N OF AIseNse Serial Number J1 J42 Temperature Sensor ONO U12 Product Name and Assembly Number 9 2 10 W3 11 SW1 12 J41 AMUX 64T User Manual Figure 2 1 AMUX 64T Parts Locator Diagram National Instruments Corporation Chapter 2 Table 2 1 Power Supply Selection Switch Description Configuration INT position Use this setting to sw1 Swi configure the AMUX 64T to draw 5 V INT N power through the MIO board factory e i setting EXT Internal Power Selected EXT position Use this setting to draw Swi 5 V power from an external supply INT connected to connector J41 EXT External Power Selected Table 2 2 Temperature Sensor Selection Jumper Description C
9. 1993 The following document contains information you may find helpful as you read this manual and is available from National Instruments upon request e Application Note 043 Measuring Temperature with Thermocouples In addition the National Instruments DAQ board user manuals contain information you may find helpful as you read this manual National Instruments Corporation Xi AMUX 64T User Manual About This Manual Customer Communication 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 AMUX 64T User Manual Xii National Instruments Corporation Introduction This chapter describes the AMUX 64T lists what you need to get started with your AMUX 64T describes the software programming choices and optional equipment and explains how to unpack your AMUX 64T About the AMUX 64T The AMUX 64T is a front end analog multiplexer that quadruples the number of analog input signals that can be digitized with a National Instruments MIO board except the AT MIO 64 The AMUX 64T has 16 separate four to one analog multiplexer circuits Four AMUX 64T boards can be cascaded to digitize up to
10. hex Two AMUX 64T boards 8 hex Four AMUX 64T boards 10 hex e Write FF41 to the Am9513 Command Register to load counter 1 e Write FFF1 to the Am9513 Command Register to step counter 1 e Write FF21 to the Am9513 Command Register to arm counter 1 After you apply this programming sequence counter 1 is configured to divide down SCANCLK during A D conversions Set the SCANDIV Bit in MIO Command Register 1 To enable SCANCLK division set the SCANDIV bit in Command Register 1 After this programming sequence the analog inputs on the AMUX 64T are automatically scanned during MIO scanned A D conversion operations AMUX 64T User Manual 5 12 National Instruments Corporation Specifications This appendix lists the specifications of the AMUX 64T These specifications are typical at 25 C unless otherwise noted Analog Input Input Characteristics Number of channels Single board Two boards Four boards connected Input signal ranges Differential analog Max working voltage signal common mode Active overvoltage protection 6 resistance National Instruments Corporation 1 64 single ended or 32 differential 128 single ended or 64 differential 256 single ended or 128 di
11. 1 3 linearizing thermocouple data 3 6 to 3 9 lowpass filters building 4 8 to 4 9 National Instruments Corporation I 3 Index lowpass filter on differential channel 1 figure 4 9 normalized frequency response figure 4 8 to 4 9 manual See documentation MIO board power budget table 2 5 multiple board configuration See configuration National Institute of Standards and Technology NIST polynomial coefficients for thermocouples table 3 8 NI DAQ driver software 1 3 to 1 5 nonreferenced or floating signal sources 4 5 to 4 6 bias return resistor for DC coupled floating source figure 4 6 differential inputs 4 5 to 4 6 single ended inputs 4 6 0 onboard temperature sensor See temperature sensor selection operation of AMUX 64T See theory of operation optional equipment 1 7 P parts locator diagram figure 2 2 physical specifications A 3 pin mapping See I O connector J1 J2 and J42 polynomial coefficients for thermocouples table 3 8 power requirement specifications A 3 AMUX 64T User Manual Index power supply selection MIO board power budget table 2 5 supplementary information 2 4 to 2 5 switch settings table 2 3 power on sequence 2 11 programming channel scanning 5 11 to 5 12 configuring Counter 1 to control MIO board scanning clock 5 12 initializing AMUX 64T scanning counter 5 11 setting SCANDIV bit in MIO Command Register 1 5 12 R register
12. 2 C is typical For more information on thermocouple wire errors and more specific data see Application Note 043 Measuring Temperature with Thermocouples Thermocouple Measurement Accuracies Table 3 4 lists the expected thermocouple accuracies in degrees Celsius subject to the following conditions e The MIO board must be correctly calibrated e The temperature of the screw terminals equals the temperature of the board no gradients on the board The uncertainties listed apply at either 0 C Type J K E T or 600 C Type S R The linearization errors of the NIST polynomials in Table 3 2 measurement error of a calibrated MIO board and the 1 C cold junction sensor error are included Thermocouple wire error is neglected because of dependence on several factors as listed above Finally these uncertainties are for the gains listed with a 10 V input range Table 3 4 Thermocouple Measurement Accuracies Type Gain J K E T S R 100 2 7 C 3 7 C 42 9 C 3 6 C 9 8 C 8 5 C 500 1 4 C 2 1 C 1 8 1 9 3 6 2 9 National Instruments Corporation 3 13 AMUX 64T User Manual Chapter 3 Signal Connections Other Connection Considerations Refer to the sections titled Analog Input Signal Connections and Cabling and Field Wiring in the Signal Connections chapter of the user manual that came with your MIO board for additional signal connection inf
13. 256 single ended or 128 differential signals by one MIO board The AMUX 64T has an integrated circuit temperature sensor that can be connected as a differential input to two of the 64 input channels jumper selectable for low cost thermocouple cold junction compensation Cold junction compensation is achieved by adding the temperature reading of the sensor to the temperature readings of thermocouples at the remaining 62 AMUX 64T input channels You can cascade up to four AMUX 64T boards to increase the number of thermocouple inputs with cold junction compensation to 248 in single ended mode or 124 in differential mode The AMUX 64T also has open component positions on all 64 input channels These positions are for building signal conditioning devices such as filters and attenuators Note When an MIO board is referred to without an AT MC NB NEC or SB prefix the reference applies to the AT MC NB NEC and SB versions of that board The AMUX 64T is a circuitboard assembly that is placed on a workbench or mounted in a 19 in rack You can configure the AMUX 64T to draw power from the MIO board or from an external 5 V supply A red LED indicates when the board is powered on Input signal leads are attached at screw terminals National Instruments Corporation 1 1 AMUX 64T User Manual Chapter 1 Introduction What You Need to Get Started Unpacking To set up and use your AMUX 64T you will need the following Q AMUX 64T bo
14. 3 gt AMUX 64T User Manual Figure 5 3 AMUX 64T Channel Address Mapping To perform an A D conversion on a single AMUX 64T channel perform the following programming steps 1 Select an analog input channel on the AMUX 64T by writing the appropriate channel address bits to digital I O port A bits 0 through 3 of the Digital Output Register 2 Write to the External Strobe Register to load the channel address into the AMUX 64T scanning counter 3 Write to the MA lt 3 0 gt bits in the Mux Gain Register to select the four to one multiplexer on the AMUX 64T you want to address Now follow the normal procedure for performing a single A D conversion or multiple A D conversions on a single input channel of the MIO board with one exception the bits MA lt 3 0 gt of the Mux Gain Register must correspond to the middle four bits of your channel address shown in Figure 5 3 5 6 National Instruments Corporation Chapter 5 Theory of Operation and Register Level Programming Automatic Channel Scanning with the AMUX 64T Automatic scanning of the AMUX 64T analog input channels is performed by the scanning counters on the AMUX 64T and the MIO board Scanning operations on the MIO board are controlled by the mux gain memory which holds a sequence of multiplexer addresses After each A D conversion the mux gain memory switches to the next multiplexer input in the sequence When the MIO board is used alone a single level multiplex
15. AMUX 64T channels are scanned for every MIO board input channel for different AMUX 64T configurations Observe that channels 0 through 15 of the MIO board are used for a single ended input configuration but only channels 0 through 7 are used for a differential input configuration Table 5 3 AMUX 64T Scanning Order for Each MIO Board Input Channel AMUX 64T Channels One Board Two Boards Four Boards MIO Board BoardA Board A Board B Board Board B Board C Board D 0 0 3 0 3 64 67 0 3 64 67 128 131 192 195 1 4 7 4 7 68 71 4 7 68 71 132 135 196 199 2 8 11 8 11 72 75 8 11 72 75 136 139 200 203 3 12 15 12 15 76 79 12 15 76 79 140 143 204 207 4 16 19 16 19 80 83 16 19 80 83 144 147 208 211 5 20 23 20 23 84 87 20 23 84 87 148 151 212 215 6 24 27 24 27 88 91 24 27 88 91 152 155 216 219 7 28 31 28 31 92 95 28 31 92 95 156 159 220 223 8 32 35 32 35 96 99 32 35 96 99 160 163 224 227 9 36 39 36 39 100 103 36 39 100 103 164 167 228 231 10 40 43 40 43 104 107 40 43 104 107 168 171 232 235 11 44 47 44 47 108 111 44 47 108 111 172 175 236 239 12 48 51 48 51 112 115 48 51 112 115 176 179 240 243 13 52 55 52 55 116 119 52 55 116 119 180 183 244 247 14 56 59 56 59 120 123 56 59 120 123 184 187 248 251 15 60 63 60 63 124 127 60 63 124 127 188 191 252 255 AMUX 64T User Manual 5 10 National Instru
16. MIO board power and signal connections Chapter 3 Signal Connections describes the AMUX 64T signal connections and has specifications and connection instructions for the AMUX 64T connector signals Chapter 4 Signal Conditioning discusses signal conditioning and describes how to build systems such as filters and attenuators for passive analog input signal conditioning Chapter 5 Theory of Operation and Register Level Programming contains a functional overview of the AMUX 64T and explains the operation of each functional unit making up the AMUX 64T This chapter also contains register level programming information for the MIO board Appendix A Specifications lists the specifications for the AMUX 64T ix AMUX 64T User Manual About This Manual e Appendix B Customer Communication contains forms you can use to request help from National Instruments or to comment on our products and manuals 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 Jndex contains an alphabetical list of key terms and topics in this manual including the page where you can find each one Conventions Used in This Manual ar LN bold italic italic E Series MC MIO board monospace NB PC AMUX 64T User Manual The following conventions are used in this manual This icon to the left of bold italic
17. 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 Under the cop
18. configuration chapter of the user manual that came with your MIO board An Example of Using Thermocouples Differential or Single Ended For this example assume that a J type thermocouple is connected to differential channel 1 and is being used to measure a high pressure boiler system The maximum temperature that can be reached is 300 C Before taking readings it is necessary that you configure the MIO board for the maximum resolution possible A thermocouple table shows that the output voltage will never exceed 16 to 17 mV recall that the exact voltage measured is a function of the AMUX 64T temperature as well as the temperature being measured Therefore you could select either a 5 V input range with a gain of 100 50 mV maximum signal or a 10 V input range with a gain of 500 20 mV maximum signal In this case the 10 V National Instruments Corporation 3 9 AMUX 64T User Manual Chapter 3 Signal Connections input range with a gain of 500 gives the best resolution Set the jumpers on the MIO board for differential input 10 V input range Note Set jumper W1 on the AMUX 64T to select the temperature sensor and connect the thermocouple to CH1 and CH33 Connect a resistor between CH33 and GND for the bias current return path Set the jumpers on the MIO board for single ended input 10 V input range Set jumper W1 on the AMUX 64T to select the temperature sensor and connect the thermocouple to Two software
19. counter configures the AMUX 64T for one board two board or four board operation Individual AMUX 64T boards are selected depending on the higher order two bits of the scanning counter The AMUX 64T contains an onboard switch to either power the AMUX 64T from the MIO board or to supply 5 V externally From the 5 V power an onboard DC to DC converter generates a 15 V source which is used to power the multiplexers The MIO board can supply enough 5 V power to drive up to four AMUX 64T boards except the MC MIO 16 which can power only two boards How to Address AMUX 64T Analog Input Channels A D Conversions on a Single AMUX 64T Analog Input Channel Before an AMUX 64T channel can be selected digital I O port A must be enabled as a digital output port You can enable this port by setting the bit in the MIO Command Register 2 this bit has different names depending on your MIO board This bit needs to be set only once after initializing the MIO board The scanning counter is used to select individual multiplexer inputs and individual AMUX 64T boards The bit assignment for the scanning counter and MIO board digital I O port A is shown in Figure 5 2 These Digital Output Register bits are loaded into the Scanning Counter and used to select AMUX 64T channels ADO3 ADO2 ADO1 ADOO Channel Select Board Select Figure 5 2 Scanning Counter Control Bits Bits ADOO and AD
20. in this example the input channel has a 6 37 resistor or closest standard value in its capacitor position G The closest standard 5 tolerance resistors are 6 2 kQ The closest standard 1 resistors are 6 34 kQ Figure 4 6 shows both the schematic and the component placement for a 50 kHz highpass filter placed on differential input channel 1 If the input signal source is floating you must place a bias return resistor in D position 8 in this case CF Note Highpass filters generally exhibit poorer common mode rejection characteristics than lowpass filters because capacitors are in the series input paths Capacitors have poorer tolerances than resistors and matching of the input impedances is crucial for good common mode rejection Do not install RC highpass filters on the AMUX 64T board open component locations when the MIO board is configured for single ended inputs National Instruments Corporation 4 11 AMUX 64T User Manual Chapter 4 Signal Conditioning E R67 A R5 Channel 1 B R6 in off C R7 Z Channel 33 F R68 in D R8 6 34 KQ Resistor 0 001 uF Capacitor Input Schematic Channel 2 gt E 0 001 uF To Input G 6 34 Multiplexer F 0 001 Channel 2 gt Figure 4 6 Highpass Filter on Differential Channel 1 Building Attenuators Voltage Dividers
21. the problem AMUX 64T 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 Hardware revision Serial number Temperature sensor selection temperature or CHO and CH32 Power supply selection internal or external Programming choice National Instruments software Other boards in system NI DAQ 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 Documentation Comment 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 AMUX 64T User Manual Edition Date January 1999 Part Number 320253 01 Please comment on the completeness clarity and organization of the manual If
22. to be a substitute for any form of established process procedure or equipment used to monitor or safeguard human health and safety in medical or clinical treatment Contents About This Manual Organization of This Manual 00 cece essent nennen nnnm ix Conventions Used in This Manual esee nennen X National Instruments Documentation enne xi Related Documentation pcne tame tre tit RR tel Re anes xi Customer Communication xii Chapter 1 Introduction About the e e es 1 1 What You Need to Get Started 1 2 Unpacking iem RUE ERR 1 2 Software Programming Choices seen 1 2 LabVIEW and LabWindows Application Software sess 1 3 NI DAQ Driver Software 1 3 Register Level Programming 1 6 Optional Equipment ee 1 7 Chapter 2 Configuration and Installation Board Configuration 2 1 Power Temperature Sensor and Shield Configuration 2 1 Supplementary Configuration Information serere 2 4 Power Supply Selection sss 2 4 Temperature Sensor espace itae 2 5 Shield Selection ili tee iter deter reis 2 6 Sin
23. with U12 set for single board configuration as shown in Table 2 5 Two Board Configuration For the two board single ended configuration assign one board channel addresses from 0 to 63 and assign the other board channel addresses from 64 to 127 For differential operation assign one board channel addresses 0 through 31 and assign the other board channel addresses 32 through 63 The board that you assign addresses 0 through 63 or 0 through 31 is referred to as board A and the board that you assign addresses 64 through 127 or 32 through 63 is referred to as board B You can configure any board as board A or board B as shown in Table 2 7 Table 2 7 U12 Switch Settings for Two Board Configuration Channel Address Range Switches Board Single Ended Differential Swi SW2 SW3 SW4 SW5 Board A 0 63 0 31 ON OFF ON OFF OFF Board B 64 127 64 95 OFF OFF ON OFF OFF The switch settings for board A and board B in a two board configuration are shown in Table 2 5 Four Board Configuration For the four board configuration each board has a different switch setting You assign the first board channel addresses from 0 to 63 the second board channel addresses from 64 to 127 the third board channel addresses from 128 to 191 and the fourth board channel addresses from 192 to 255 For differential operation assign the first board channel addresses 0 through 31 the second board channel addr
24. 0 02 C 0 01 C 0 04 C to 0 02 C 0 04 C to 0 05 C Co 0 0000000 1 334584505E 1 0 00000000 1 291507177E 1 0 000000 0 000000 1 1 8891380E 1 1 472644573E 1 1 84949460E 1 1 466298863 2 5173462E 2 2 508355E 2 Co 9 3835290E 5 1 844024844E 5 8 00504062E 5 1 534713402E 5 1 1662878E 6 7 860106E 8 C3 1 3068619E 7 4 031129726E 9 1 02237430E 7 3 145945973E 9 1 0833638E 9 2 503131 10 4 2 2703580E 10 6 249428360E 13 1 52248592E 10 4 163257839E 13 8 9773540E 13 8 315270E 14 C5 3 5145659E 13 6 468412046E 17 1 88821343E 13 3 187963771E 17 3 73423TTE 16 1 228034E 17 C6 3 8953900E 16 4 458750426E 21 1 59085941E 16 1 29163750E 21 8 6632643E 20 9 804036E 22 C7 2 8239471E 19 1 994710149E 25 8 23027880E 20 2 183475087E 26 1 0450598 23 4 413030 26 Cg 1 2607281E 22 5 313401790E 30 2 34181944E 23 1 447379511 31 5 1920577 28 1 057734 30 Co 3 135361 1E 26 6 481976217E 35 2 79786260E 27 8 211272125E 36 1 052755E 35 Cjo 3 3187769 30 101dey9 9 729 2 5 Chapter 3 Signal Connections These polynomials are accurate only within the temperature ranges specified Also all terms must be included to achieve the specified accuracy To avoid the long computation time required for these high order polynomials the operating ran
25. 1 R142 R143 R144 103 R104 C40 20 20 52 R145 R146 R147 148 R105 R106 C41 21 21 53 R149 150 R151 152 R107 108 C42 22 22 54 R153 R154 155 R156 109 110 C43 23 23 55 R157 158 R159 160 R111 112 C44 24 24 56 R161 R162 R163 R164 R113 114 C45 25 25 57 R165 R166 R167 168 R115 116 C46 26 26 58 R169 R170 R171 172 R117 118 C47 27 27 59 R173 R174 R175 R176 119 R120 C48 28 28 60 R177 R178 R179 180 R121 122 C49 29 29 61 R181 R182 R183 R184 R123 124 C50 National Instruments Corporation 4 3 AMUX 64T User Manual Chapter 4 Signal Conditioning Table 4 1 Component Positions in Each Channel Continued Channel Positions in Figure 4 1 Differential Single Channel A B G 30 30 62 R185 186 187 R188 125 126 C51 31 31 63 R189 190 191 192 127 128 C52 When the board is shipped jumpers are inserted in the E and F positions of the input network see Figure 4 1 You can easily remove these jumpers to build analog input signal conditioning circuits Several applications showing the use of these open component positions are discussed in the next section Application Notes Application Notes The open component positions on the AM
26. 42 National Instruments Corporation 3 1 AMUX 64T User Manual Chapter 3 Signal Connections Table 3 1 Pin Mapping for 1 0 Connectors J1 J2 and J42 50 Pin Connector 68 Pin Connector J42 J1 and J2 Pin Numbers Pin Numbers 1 2 24 27 29 32 56 59 64 67 3 68 4 34 5 33 6 66 7 65 8 31 9 30 10 63 11 28 12 61 13 60 14 26 15 25 16 58 17 57 18 23 19 62 20 22 21 21 22 20 23 54 55 24 33 4 7 9 12 13 15 18 35 36 39 44 50 53 AMUX 64T User Manual 3 2 National Instruments Corporation Chapter 3 Signal Connections Table 3 1 Pin Mapping for 1 0 Connectors J1 and J42 Continued 50 Pin Connector 68 Pin Connector J42 J1 and J2 Pin Numbers Pin Numbers 25 52 26 19 27 17 28 51 29 49 30 16 31 4T 32 48 34 35 8 14 36 46 37 45 38 11 39 10 40 43 41 42 42 41 43 40 44 6 45 5 46 38 47 37 48 3 49 2 50 1 National Instruments Corporation 3 3 AMUX 64T User Manual Chapter 3 Signal Connections The signals from the AMUX 64T input connector screw terminals are connected to the MIO board via J1 J2 or J42 as shown in Figure 3 1 Observe that AISENSE is connected directly to the MIO board AISENSE pin and that AIGND on the AMUX 64T is connected to the AIGND signal
27. 5 8935 59 9 amp Sigo uoo 9 lt Rioj 9 512 9 6 8610 of 8610 33 Fe c ORIS40 81916 rao o 9 566 SA cre 68 36 2 58 46 ar OfRizio O 081416 81035 O R7IJO O R13O E 08680 Ofriaio Sg 89 OR 681440 881545 6 87 618186 ichas 1 9 R73 o 170 cua 6368 Sg N c w oc SO 200 or 0 o n7sjo O Re1O SZ o jog CHS o lolol O R3O I5 GE cus 92 o 8786 o R240 O R77 O O R250 e 9 5 pe o o loi og270 87 6 O Re8O O LICH38 7 o esdo x AISENSE 7 y OZLAISENSE B 7 o 9 Sn E on g OMAIGND cat cae 5 8335 enado 5 SSeS EP Sge ou 55 58 7 528525 61 OE 18846 O o 1 cues o 9 o S joa 652869 2 o D 52806 57 6 9 9259 O 8578 5 99 0 5 SLC 8686 6816 65 5696 Oeo ww 9 oido 6 14 G 618446 5 o 618486 E 6 Bee 69486 1 e O R470 cess o 15586 S
28. 8 pin shielded or ribbon cable from the 68 pin MIO board I O connector to J42 on the AMUX 64T If you use more than one AMUX 64T you can daisy chain the boards by connecting J1 or J2 on one AMUX 64T to J1 or J2 on another AMUX 64T and so on see Figure 2 2 You can install the AMUX 64T into a 19 in rack mount kit as shown in Figure 2 3 If you use a round 68 pin shielded cable route the cable as shown leaving passage for the ribbon cable if you use it for daisy chaining in the other direction AMUX 64T User Manual 2 10 National Instruments Corporation Chapter 2 Configuration and Installation Figure 2 3 Cable Positioning for the AMUX 64T Power On Sequence If the AMUX 64T is powered by an external power source you must turn on power to the AMUX 64T before turning on the computer Similarly you must turn off power to the AMUX 64T after turning off the computer The red LED labeled D2 indicates when power is applied to the board National Instruments Corporation 2 11 AMUX 64T User Manual Signal Connections AN Warning AN Caution This chapter describes the AMUX 64T signal connections and has specifications and connection instructions for the AMUX 64T connector signals The following warnings contain important safety information concerning hazardous voltages Connections that exceed any of the maximum ratings of input signals on the AMUX 64T board can damage the AMUX 64T the M
29. 879 6277 0662 45 79 90 19 02 757 03 11 011 288 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 9 640 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 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
30. AN Warning AMUX 64T User Manual You can connect attenuators voltage dividers to the analog inputs of the AMUX 64T board when the inputs from its DAQ board are in differential mode Do not install voltage dividers on the AMUX 64T board open component locations when the MIO board is configured for single ended inputs You can use attenuators to reduce a signal that is outside the normal input range of the DAQ board 10 V max The AMUX 64T board is not designed for any input voltages greater than 42 V even if a user installed voltage divider reduces the voltage to within the input range of the DAQ board Input voltages greater than 42 V can result in damage to the AMUX 64T board any and all boards connected to it and the host computer Overvoltage can also cause an electric shock hazard for the operator National Instruments is Nor liable for damage or injury resulting from such misuse 4 12 National Instruments Corporation Chapter 4 Signal Conditioning A three resistor circuit for attenuating voltages at the differential inputs of the AMUX 64T board is shown in Figure 4 7 The figure also shows the placement of the resistors on the open component positions for differential Channel 1 The gain G of this attenuator is given by the following equation G 4 3 Therefore the input to the MIO board is Vuro Vsc where Vgc is the voltage applied to the screw terminals of the AMUX 64T The accuracy of this g
31. DAQ AMUX 64T User Manual Analog Multiplexer with Temperature Sensor NATIONAL i J 1999 Editi INSTRUMENTS Part suber EAE Internet Support E mail support natinst com FTP Site ftp natinst com Web Address http 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 512 418 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 1989 1999 National Instruments Corporation All rights reserved Important Information Warranty Copyright Trademarks The AMUX 64T is warranted against defects in materials and workmanship for a period of one year from the date of shipment as evidenced by receipts or other documentation
32. Figure 4 5 Normalized Frequency Response of Highpass Filter When measuring high frequency signals about 50 kHz if you have 50 Hz noise on your inputs you can add a highpass filter with a cutoff frequency of 50 kHz The 50 Hz noise then attenuates by 60 dB Notice that your 50 kHz signal also attenuates but by only 3 dB Do not neglect any potential attenuation of signals of interest if you add a low order filter You must also choose the filter component values You can select the resistance or the capacitance arbitrarily one value determines the other Picking the capacitor first and letting its value determine the resistance required is preferable because more standard resistor values are available 4 10 National Instruments Corporation Chapter 4 Signal Conditioning The filter circuit has one series capacitor on each input of the differential channel Because the two capacitors are in series the capacitance value that must be substituted into equation 4 2 is the series capacitance of the two capacitors in series For two capacitors in series the net capacitance is the reciprocal of the sum of the reciprocals of the two capacitances For example two 0 001 uF capacitors in series have a net capacitance of 0 0005 uF The two capacitors should be the same value or the common mode rejection is degraded If capacitors of 0 001 UF are available the resistance is by substitution into equation 4 2 6 366 Q or about 6 4 Therefore
33. IO board or the computer This includes connecting any power signals to ground and vice versa Maximum input ratings are given in Appendix A Specifications National Instruments is liable for any damages resulting from signal connections that exceed these ratings Do NOT OPERATE DAMAGED EQUIPMENT The safety protection features built into this board can become impaired if the board becomes damaged in any way If it is damaged disconnect power and do not use the board until service trained personnel can check its safety If necessary return the board to National Instruments for service and repair to ensure that its safety is not compromised Do NOT SUBSTITUTE PARTS OR MODIFY EQUIPMENT Because of the danger of introducing additional hazards do not install unauthorized parts or modify the board Return the board to National Instruments for service and repair to ensure that its safety features are not compromised NEVER connect a signal to screw terminals CHO CH63 that violates their overvoltage protection limits When the AMUX 64T is powered on the screw terminals CH0 CH63 overvoltage protection is 35 V when the AMUX 64T is powered off overvoltage protection is 20 V 1 0 Connector Connectors J1 and J2 are connected together pin by pin and have exactly the same pinout as the 50 pin MIO board I O connector J42 has the exact same pinout as the 68 pin MIO board I O connector Table 3 1 shows the pin mapping between J1 J2 and J
34. MUX 64T to the MIO board power and signal connections Board Configuration The AMUX 64T contains two sets of switches and three jumpers to change the multiplexer settings and power connection configurations of the board These jumpers and switches are shown in Figure 2 1 The five position switch at U12 configures the AMUX 64T for single board or multiple board operation Switch SW1 selects either the internal 5 V power from the MIO board or an external 5 V power source for the AMUX 64T Jumper W1 optionally connects the onboard temperature sensor to Channels 0 and 32 of the AMUX 64T Jumper W2 connects the AMUX 64T analog ground to the shield of a rack mounted chassis Jumper W3 connects the AMUX 64T 68 pin connector shield to the shield of a rack mounted chassis Power Temperature Sensor and Shield Configuration To configure the AMUX 64T board use the three user configurable jumpers W1 W3 shown in the parts locator diagram Figure 2 1 Tables 2 1 to 2 3 list the description and configuration of the user configurable jumpers National Instruments Corporation 2 1 AMUX 64T User Manual Chapter 2 Configuration and Installation
35. 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 documet 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 In no event shall
36. O address each four to one multiplexer on the AMUX 64T and work in combination with the MIO Mux Gain Register the Mux Mem Register in the AT MIO 16F 5 to select the analog input channel An address map for selecting analog input channels on a single AMUX 64T is shown in Table 5 1 National Instruments Corporation 5 3 AMUX 64T User Manual Chapter 5 Theory of Operation and Register Level Programming Table 5 1 AMUX 64T Channel Selection Channel Mux Gain Register Digital Port A Bits Number lt 3 0 gt ADO lt 1 0 gt 0 0000 00 1 0000 01 2 0000 10 3 0000 11 4 0001 00 5 0001 01 6 0001 10 7 0001 11 28 0111 00 29 0111 01 30 0111 10 31 0111 11 32 1000 00 33 1000 01 34 1000 10 35 1000 11 60 1111 00 61 1111 01 62 1111 10 63 1111 11 AMUX 64T User Manual 5 4 National Instruments Corporation Chapter 5 Theory of Operation and Register Level Programming Bits ADO2 and ADO3 select each individual AMUX 64T board in a multiple board configuration If you use only one AMUX 64T board ADO2 and ADO3 are ignored If you use two AMUX 64T boards only ADO 2 is used An address map for the different channel groups is shown in Table 5 2 Table 5 2 Multiple AMUX 64T Board Addressing Digital Port A Bits ADO lt 3 2 gt Board Selected Channels Selected 00 A 0 63 01 B 64 127 10 C 128 191 11 D 192 255 Observ
37. UX 64T board make adding signal conditioning components to the analog input signals easier Several applications are covered in this section including filtering and attenuation The figures in this section give examples on a specific input channel If you want to install the circuit on a different channel consult Table 4 1 to determine the equivalent component positions for the other channels Soldering and Desoldering on the AMUX 64T Board Cr Note The following applications require you to make modifications to the printed circuit board usually in the form of removing jumpers and adding components The AMUX 64T board is shipped with wire jumpers in the E and F positions see Table 4 1 and Figure 4 1 Remove the plastic insulator on the bottom of the AMUX 64T before removing wire jumpers or adding components to the board To remove the insulator unscrew the standoffs from the top of the board the insulator and standoffs should fall off Replace the insulator and standoffs after completing your modifications to the board AMUX 64T User Manual Use a low wattage soldering iron 20 to 30 W when soldering to the board To desolder on the AMUX 64T use vacuum type tools for best results Use care when desoldering to avoid damaging component pads You should use only rosin core electronic grade solder Acid core solder damages the printed circuit board and components 4 4 National Instruments Corporation Chapter 4 Signal Condition
38. ain equation depends on the tolerances of the resistors used Channel 1 B R6 in ff 2 33 m 10 kQ Resistor Input Schematic Channel oS eae E 10 kQ G To Vsc 10 MIO board F 10 Channel ZEE Figure 4 7 Attenuator for Use with Differential Inputs Vio National Instruments Corporation 4 13 AMUX 64T User Manual Chapter 4 Signal Conditioning Example Using the values in Figure 4 7 Qus UN m 10kQ4 10kKQ 10kQ 3 Therefore 1 3 C When the MIO board is configured for 10 V inputs the board can acquire x30 V signals with this attenuator circuit AMUX 64T User Manual 4 14 National Instruments Corporation Theory of Operation and Register Level Programming This chapter contains a functional overview of the AMUX 64T and explains the operation of each functional unit making up the AMUX 64T This chapter also contains register level programming information for the MIO board If you plan to use a software package such as Lab Windows NI DAQ or LabVIEW with your MIO board you need not read this chapter Functional Overview Figure 5 1 shows the block diagram of the AMUX 64T The AMUX 64T contains 16 CMOS four to one analog multiplexers for a total of 64 channels Each analog multiplexer expands a single MIO analog input channel to four AMUX 64T analog input channels
39. alent to the NI DAQ software except that the SCXI functions are not included in the LabWindows CVI software for Sun Using LabVIEW or LabWindows 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 digital I O counter timer operations SCXI RTSI self calibration messaging and acquiring data to extended memory National Instruments Corporation 1 8 AMUX 64T User Manual Chapter 1 Introduction NI DAQ has both high level DAQ functions for maximum ease of use and low level data acquisition 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 data acquisition device NI DAQ does not sacrifice the performance of National Instruments data acquisition devices because it lets multiple devices operate at their peak performance up t
40. ard AMUX 64T User Manual L 0 2 0 5 1 0 or 2 0 m cable L MIO board Detailed specifications of the AMUX 64T are listed in Appendix A Specifications Your AMUX 64T board is shipped in an antistatic package to prevent electrostatic damage to the device Electrostatic discharge can damage several components on the device To avoid such damage in handling the device take the following precautions e Touch the antistatic package to a metal part of your computer chassis before removing the device from the package e Remove the device from the package and inspect the device for loose components or any other sign of damage Notify National Instruments if the device appears damaged in any way Do not install or connect a damaged device in your computer or to your MIO device e Never touch the exposed pins of connectors Software Programming Choices AMUX 64T User Manual There are four options to choose from when programming your National Instruments DAQ and SCXI hardware You can use LabVIEW LabWindows NI DAQ or register level programming software Your accessory hardware kit does not include software The AMUX 64T works with LabVIEW for Windows LabVIEW for Macintosh LabWindows for DOS and LabWindows CVI for Windows NI DAQ for PC compatibles and NI DAQ for Macintosh 1 2 National Instruments Corporation Chapter 1 Introduction LabVIEW and LabWindows Application Software LabVIEW and LabWindows are innovat
41. ard is configured for differential inputs ground referenced signal sources connected to the AMUX 64T board need no special components added to the AMUX 64T board You can leave the inputs of the AMUX 64T board in the factory original condition that is with only jumpers in the two series positions E and F see Table 4 1 You can build signal conditioning circuitry such as filters and attenuators described in Building Lowpass Filters Building Highpass Filters and Building Attenuators Voltage Dividers later in this chapter in the open component positions Single Ended Inputs When measuring ground referenced signals the external signal supplies its own reference ground point and the MIO board should not supply one Therefore you should configure the MIO board for nonreferenced single ended input mode In this configuration you should tie all of the signal grounds to AISENSE which connects to the negative input of the instrumentation amplifier on the MIO board You can leave the inputs of the AMUX 64T board in the factory default condition that is with jumpers in the series position or F depending on the channel You should not use the open positions that connect the input to AIGND B and D see Table 4 1 and Figure 4 1 in this configuration Therefore you should not build signal conditioning circuitry requiring a ground reference in the open component positions Referencing the signal to AIGND can cause inaccurate measurements
42. ass filters on the AMUX 64T board open component locations when the MIO board is configured for single ended inputs E R67 EN 1 B R6 in G C4 C R7 F R68 pron 33 mF mm 19 8 kQ Resistor 1 uF Capacitor Input Schematic Channel 19 8 To G ____1 Input Multiplexer F 19 8 kQ Channel Figure 4 4 Lowpass Filter on Differential Channel 1 National Instruments Corporation 4 9 AMUX 64T User Manual Chapter 4 Signal Conditioning Building Highpass Filters You can easily install simple RC highpass filters in the AMUX 64T board on any differential input channel The filters are useful for accurate high frequency measurement and low frequency noise rejection By substituting resistance and capacitance values into the following equation hereafter referred to as equation 4 2 you can calculate a simple one pole filter to have a 3 dB point fc or cutoff frequency _ 1 fe 2xRC 4 2 The frequency response rolls off at a rate of 20 dB per decade decrease thereafter A Bode plot of the amplitude versus normalized frequency is shown in Figure 4 5 Amplitude 14 0 1 4 0 01 7 0 001 4 0 0001 4 0 0001 0 001 0 01 0 1 1 10 fe Normalized Frequency AMUX 64T User Manual
43. ating source to the ground of the DAQ board to establish a local or onboard reference for the signal Differential Inputs To provide a return path for the instrumentation amplifier bias currents floating sources must have a resistor connected to AIGND on one input if the signal is DC coupled or both inputs if the signal is AC coupled For more detailed information on connections to floating signal sources and differential inputs refer to the configuration chapter in the user manual that came with your MIO board You can install these bias resistors in positions B and D Table 4 1 and Figure 4 1 of the AMUX 64T board Figure 4 2 shows both the schematic and the component placement for a single 100 bias return resistor on the negative input from a floating source connected to channel 1 the D position in Table 4 1 You can build additional signal conditioning circuitry such as filters and attenuators described in Building Lowpass Filters Building Highpass Filters and Building Attenuators Voltage Dividers later in this chapter in the open component positions National Instruments Corporation 4 5 AMUX 64T User Manual Chapter 4 Signal Conditioning E 867 A R5 Channel 1 O em B R6 G c4 Jumper C R7 Channel 33 en aM 100 kO Resistor Input Schematic Channel 2 O p AIGND To Input G Multiplexer 100 kQ 5 Channel 2 O O g
44. attenuates by 40 dB Notice that your 4 Hz signal also attenuates but by only 3 dB Do not neglect any potential attenuation of signals of interest by this low order filter You must also choose the filter component values You can select the resistance or the capacitance arbitrarily one value determines the other Picking the capacitor first and letting its value determine the resistance required is preferable because more standard resistor values are available AMUX 64T User Manual 4 8 National Instruments Corporation Chapter 4 Signal Conditioning If a capacitance of 1 UF is available the resistance is by substitution into the equation 39 789 Q or about 39 8 kO This resistance must be divided by two to get the resistor value on each input of a differential channel Therefore in this example each input has a 19 89 kQ resistor or closest standard value in its series positions E and F The closest standard 5 tolerance resistors are 20 kO The closest standard 0 5 resistors are 19 8 kQ National Instruments recommends using 1 or better tolerance resistors in this application because differences between the resistor values degrade the common mode rejection ratio Figure 4 4 shows both the schematic and the component placement for a 4 Hz lowpass filter placed on differential input channel 1 If the input signal source is floating you must place a bias return resistor in the D position R6 in this case Do not install RC lowp
45. board 4 4 signal connections 3 1 to 3 14 cautions and warnings 3 1 differential connections 3 5 exceeding maximum input ratings warning 3 1 I O connector 3 1 to 3 4 AMUX 64T signal routing figure 3 4 pin mapping for J1 J2 and J42 table 3 2 to 3 3 other connection considerations 3 14 thermocouple measurements using AMUX O64T 3 5 to 3 13 differential measurements 3 9 National Instruments Corporation examples differential or single ended 3 9 to 3 11 linearizing the data 3 6 to 3 9 NIST polynomial coefficients for thermocouples table 3 8 selecting gain and input ranges 3 5 to 3 6 single ended measurement 3 11 sources of error 3 12 to 3 13 thermocouple measurement accuracies 3 13 thermocouple output extremes table 3 6 using more than one AMUX 64T 3 12 single board configuration See configuration single ended inputs ground referenced signal sources 4 7 nonreferenced or floating signal sources 4 6 single ended thermocouple measurement example 3 9 to 3 11 procedure 3 11 software programming choices LabVIEW and LabWindows application software 1 3 NI DAQ driver software 1 3 to 1 5 register level programming 1 6 soldering and desoldering on AMUX 64T board 4 4 specifications AMUX 64T settling times to 12 bit precision A 2 to A 3 analog input A 1 cold junction sensor A 3 environment A 4 physical A 3 power requirement A 3 switch settings See configuration National Instrum
46. compensation procedures for this example follow Procedure 1 is more accurate but procedure 2 is faster and requires less computation Procedure 1 1 AMUX 64T User Manual Read the voltage from the temperature sensor channel 0 If you are using NI DAQ you can use the AI_Read and AI_Scale functions to do the reading This voltage is 10 mV C so the gain should be either 1 or 10 10 for the best resolution Multiply the voltage by 100 to get the AMUX 64T temperature in degrees Celsius For example if the reading is 0 25 V the AMUX 64T is at 25 C Translate the reading into the voltage for a J type thermocouple at that temperature using either a look up table or an NIST polynomial Notice that the polynomials required here are the inverses of those given in Table 3 3 For your reading of 25 C you would have 1 277 mV Read the voltages on any thermocouple channels If you are using NI DAQ you can use the Read and A1 Scale functions to read each channel For the example given assume that you get a reading of 9 39 mV on channel 1 Add the voltage from step 2 to the voltage measured in step 3 You then have 1 277 9 39 10 667 mV Translate the result into a temperature using either a look up table or a polynomial such as one from Table 3 3 For example assume that the reading from the J type thermocouple is 10 667 mV By applying the third formula in the Linearizing the Data section and using the coefficients fro
47. e If you are using the thermocouples in a known temperature range consult a book of thermocouple tables to determine the approximate millivolt output and the best gain and input range settings National Instruments Corporation 3 5 AMUX 64T User Manual Chapter 3 Signal Connections AN Caution NEVER connect a signal to screw terminals CHO CH63 that violates their overvoltage protection limits When the AMUX 64T is powered on the screw terminals CH0 CH63 overvoltage protection is 35 V when the AMUX 64T is powered off overvoltage protection is 20 V Table 3 2 Thermocouple Voltage Output Extremes mV Thermocouple Low High J 8 095 at 210 C 69 553 at 1 200 C K 6 458 at 270 C 54 886 at 1 372 C E 9 835 at 270 C 76 373 at 1 000 C T 6 258 at 270 C 20 872 at 400 C S 0 236 at 50 C 18 693 at 1 768 C R 0 226 at 50 C 21 101 at 1 768 C B 0 000 at 0 C 13 820 at 1 820 C Source of information is NIST Monograph 175 Temperature Electromotive Force Reference Functions and Tables for the Letter Designated Thermocouple Types Based on the ITS 90 National Institute of Standards and Technology 1993 All temperatures are the difference between the measuring end and the cold junction or AMUX 64T screw terminals in this case Linearizing the Data AMUX 64T User Manual Thermocouple output voltages are highly nonlinear The Seebeck coefficient or
48. e semiconductor Counter Interrupt signal digital to analog Data Address signal digital to analog converter DAC output update signal DAC Write signal Digital to Analog Converter 0 1 Output signals data acquisition Data Acquisition Board Data Address Line signal Data Lines at the Specified Port signal decibels direct current Digital Ground signal differential G 2 National Instruments Corporation DIN DIP DMA E EEPROM EPP EXTCONV EXTTRIG EXTUPDATE F ft G GATB lt 0 2 gt H hex IBF INTR LSB Glossary Deutsche Industrie Norme dual inline package direct memory access electrically erased programmable read only memory Enhanced Parallel Port External Convert signal External Trigger signal External Update signal feet Counter BO B1 B2 Gate signals hexadecimal Input Buffer Full signal inches Interrupt Request signal input output light emitting diode least significant bit National Instruments Corporation G 3 AMUX 64T User Manual Glossary min MIO MSB NRSE 0 OBF OUTBO OUTBI P PA PB PC lt 0 7 gt POSTTRIG PRETRIG R RC RD Rext RSE RTSI AMUX 64T User Manual meters maximum megabytes of memory minutes multifunction I O most significant bit nonreferenced single ended Output Buffer Full signal Counter BO B1 Output signals Port A B or C 0 through 7 signals Posttrigger mode Pretr
49. e that channels on a single AMUX 64T are labeled 0 through 63 If you use more than one AMUX 64T board however channel numbering changes see Table 5 2 When you use four AMUX 64T boards with channel addresses ranging from 0 to 255 eight bits are required to address any single channel This 8 bit address must be split and written to the Digital Output Register and the Mux Gain Register the Mux Mem Register in the AT MIO 16F 5 Figure 5 3 shows the mapping of the 8 bit channel address to the Digital Output and Mux Gain Registers To select a given channel write the two least significant bits to bits ADOO and ADOI of digital I O port A the four middle bits to bits MA 3 0 of the Mux Gain Register and the two most significant bits to bits ADO3 and ADO2 of digital I O port A Notice that for differential operation bit MA3 which corresponds to bit 5 of the channel address becomes a don t care bit This occurs because only eight multiplexers are used for differential operation National Instruments Corporation 5 5 AMUX 64T User Manual Chapter 5 Theory of Operation and Register Level Programming 7 6 5 8 Bit Channel Address 4 3 2 1 0 CA7 CA6 CA5 CA4 CA3 CA2 CA1 CAO ADOO Select AMUX 64T ADO1 Channel lt 0 3 gt MAO 4 Select AMUX 64T MA2 Multiplexer lt 0 15 gt MA3 2 Select AMUX 64T ADO3 Board lt 0
50. els A D conversions on single analog input channel 5 3 to 5 6 channel address mapping figure 5 6 channel selection table 5 4 l 1 AMUX 64T User Manual Index multiple AMUX 64T board addressing table 5 5 scanning counter control bits figure 5 3 addressing analog input channels 5 3 to 5 6 component positions in each channel table 4 2 to 4 4 configuring input mode 4 5 cold junction compensation 3 5 cold junction sensor specifications A 3 configuration 2 1 to 2 10 channel configurations 4 5 four board configuration instructions 2 9 switch settings table 2 10 jumpers and switches on AMUX 64T 2 1 multiple board configuration channel ranges for multiple boards table 2 8 daisy chaining multiple boards figure 2 8 jumper settings table 2 7 parts locator diagram figure 2 2 power supply selection MIO board power budget table 2 5 supplementary information 2 4 to 2 5 switch settings table 2 3 shield selection jumper settings table 2 4 supplementary information 2 6 single board configuration factory settings 2 9 jumper settings table 2 7 temperature sensor selection jumper settings table 2 3 supplementary information 2 5 to 2 6 AMUX 64T User Manual l 2 two board configuration instructions 2 9 switch settings table 2 9 customer communication xii B 1 to B 2 D differential inputs ground referenced signal sources 4 7 nonreferenced or floating signal sources 4 5 t
51. emperature voltage conversions Procedure 2 is faster but introduces an error of 2 C To determine if the error from procedure 2 is acceptable or not in your application you can work through some examples both ways Use a thermocouple reference table and consider voltages and temperatures close to those in your application Single Ended Measurement Connect the temperature sensor to channels 0 and 32 by configuring jumper W1 as shown in Table 2 2 Temperature Sensor Selection Connect the positive leads of the thermocouples to any AMUX 64T input channels except CHO and CH32 Connect the negative leads to GND Notice that some thermocouples such as those from Omega Engineering have red insulation on the negative terminal Check with the vendor to determine the output polarity of any particular thermocouple Configure the MIO board for ground referenced single ended inputs For more information about signal sources and their connections see the Signal Connections chapter of the user manual that came with your MIO board National Instruments Corporation 3 11 AMUX 64T User Manual Chapter 3 Signal Connections Using More Than One AMUX 64T Sources of Error AMUX 64T User Manual Two cold junction compensation options are possible when thermocouples are being used with two or more AMUX 64T boards connected to one MIO board If all AMUX 64T boards are at approximately the same temperature only one needs to have the temperature sensor c
52. entary Configuration Information AMUX 64T User Manual Power Supply Selection The shaded area indicates the position of the jumper Switch SW1 selects internal or external 5 V power for the AMUX 64T Set SWI to the INT position to power the AMUX 64T by drawing power through the MIO board Set SW1 to the EXT position to draw power from an external 5 V source connected to J41 2 4 National Instruments Corporation Chapter 2 Configuration and Installation With the exception of the MC MIO 16 all MIO boards are capable of powering up to four AMUX 64T boards The MC MIO 16 has enough remaining power to start up to two AMUX 64T boards Each AMUX 64T board typically draws 78 mA Table 2 4 shows the amount of power the MIO boards can supply to the AMUX 64T Table 2 4 MIO Board Power Budget Total Number of AMUX 64Ts That Can Be Powered through Board Power Allotted Power Used Power Remaining MIO Board AT MIO 16 no restriction 15 10A 4 limited by a fuse AT MIO 16D no restriction 1 75 A 1 0A 4 limited by a fuse AT MIO 16F 5 no restriction 1 6A 1 0A 4 limited by a fuse AT MIO 16X no restriction 1 6A 1 0A 4 limited by a fuse E Series no restriction 1 0A 1 0A 4 limited by a fuse MC MIO 16 1 6A 14 0 2A 2 NB MIO 16 2 0A 15 0 5 4 NB MIO 16X 2 0 A 14 0 6A 4 SB MIO 16E 4 2 0 A 15 0 5 4 This value depends on the computer model and configuration of
53. ents Corporation l 5 Index T technical support B 1 to B 2 telephone and fax support numbers B 2 temperature sensor selection jumper settings table 2 3 supplementary information 2 5 to 2 6 theory of operation 5 1 to 5 11 A D conversions on single analog input channel 5 3 to 5 6 channel address mapping figure 5 6 channel selection table 5 4 multiple AMUX 64T board addressing table 5 5 scanning counter control bits figure 5 3 addressing analog input channels 5 3 to 5 6 automatic channel scanning 5 7 to 5 9 scanning order for different configurations figure 5 9 two level multiplexer arrangement figure 5 7 block diagram of AMUX 64T figure 5 2 functional overview 5 1 to 5 3 scanning order 5 10 to 5 11 thermocouple measurements using AMUX 64T 3 5 to 3 13 differential measurements 3 9 examples differential or single ended 3 9 to 3 11 linearizing the data 3 6 to 3 9 NIST polynomial coefficients for thermocouples table 3 8 selecting gain and input ranges 3 5 to 3 6 single ended measurement 3 11 sources of error 3 12 to 3 13 thermocouple measurement accuracies 3 13 AMUX 64T User Manual Index thermocouple output extremes table 3 6 using more than one AMUX 64T 3 12 U unpacking the AMUX 64T 1 2 voltage dividers See attenuators voltage dividers building AMUX 64T User Manual National Instruments Corporation
54. equipment 1 7 overview 1 1 parts locator diagram figure 2 2 requirements for getting started 1 2 software programming choices 1 2 to 1 6 LabVIEW and LabWindows application software 1 3 NI DAQ driver software 1 3 to 1 5 register level programming 1 6 unpacking 1 2 analog input 4 1 to 4 4 A D conversions on single channel 5 3 to 5 6 component positions in each channel table 4 2 to 4 4 input characteristics specifications A 1 onboard equivalent circuit figure 4 2 attenuators voltage dividers building 4 12 to 4 14 attenuators for use with differential inputs figure 4 13 input voltage greater than 42 V warning 4 12 National Instruments Corporation automatic channel scanning See channel scanning block diagram of AMUX 64T figure 5 2 board configuration See configuration bulletin board support B 1 cables See also shield selection optional equipment 1 7 63 screw terminals never connecting signals to caution 3 1 channel scanning automatic 5 7 to 5 9 scanning order for different configurations figure 5 9 two level multiplexer arrangement figure 5 7 programming 5 11 to 5 12 configuring Counter to control MIO board scanning clock 5 12 initializing AMUX 64T scanning counter 5 11 setting SCANDIV bit in MIO Command Register 1 5 12 scanning counter control bits figure 5 3 scanning order description 5 10 to 5 11 MIO board input channels table 5 10 chann
55. er switches the 16 input channels to the analog to digital converter ADC A two level multiplexer must be controlled when an AMUX 64T board is connected to the MIO board The AMUX 64T switches 64 inputs down to 16 outputs and the MIO board switches 16 inputs down to 1 output going to the ADC as shown in Figure 5 4 AMUX 64T CHO CH1 CHa CH2 WRA 8 ooo oo CH6 1 A 677 fg CH6 Gra cuz CHio CH8 Xo o o CH9 To ADC eec CH10 AN CH11 duc CH12 m y CH13 Be o CH14 Pa CH15 CH60 CH61 CH62 lt CH63 e Cable 64 to 16 Multiplexer 16 to 1 Multiplexer MIO board Figure 5 4 Two Level Multiplexer Arrangement Showing Channel 9 Selected National Instruments Corporation 5 7 AMUX 64T User Manual Chapter 5 Theory of Operation and Register Level Programming AMUX 64T User Manual When operating stand alone the MIO board selects a new input channel after each A D conversion A clock signal SCANCLK is generated by the MIO board and starts each A D conversion on the rising edge of the signal This clock also increments the onboard scanning counter When a single AMUX 64T board is connected to the MIO board four AMUX 64T input channels must be scanned for every MIO b
56. eries DAQ boards are packaged with NI DAQ software for Sun which comes with a language interface for ANSI C 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 The only users who should consider writing register level software should meet at least one of the following criteria e National Instruments does not support your operating system or programming language e You are an experienced register level programmer who is more comfortable writing your own register level software Even if you are an experienced register level programmer always consider using NI DAQ LabVIEW or LabWindows to program your National Instruments DAQ hardware Using the NI DAQ LabVIEW or LabWindows software is easier than and as flexible as register level programming and can save you weeks of development time The AMUX 64T User Manual and your software manuals contain complete instructions for programming your AMUX 64T with NI DAQ LabVIEW or LabWindows For register level programming information see Chapter 5 Theory of Operation and Register Level Programming If you are using NI DAQ with LabWindows use this manual and your LabWindows software manual If you are using LabVIEW use your LabVIEW manual If you are using NI DAQ LabVIEW or LabWind
57. esses 32 through 63 the third board channel addresses 64 through 95 and the fourth board channel addresses 96 through 127 The board that you assign addresses 0 through 63 or 0 through 31 is referred to as board A the board that you assign addresses 64 through 127 or 32 through 63 is referred to as board B the board that you assign addresses 128 to 191 or 64 through 95 is referred to as board C and the board that you assign addresses 192 through 255 or 96 through 127 is referred to as board D You can configure any board as board A board B board C or board D as shown in Table 2 8 National Instruments Corporation 2 9 AMUX 64T User Manual Chapter 2 Configuration and Installation Table 2 8 U12 Switch Settings for Four Board Configuration Channel Address Range Switches Board Single Ended Differential Swi SW2 SW3 SW4 SW5 Board A 0 63 0 31 ON ON ON ON OFF Board B 64 127 64 95 OFF ON ON ON OFF Board C 128 191 128 159 ON OFF ON ON OFF Board D 192 255 192 223 OFF OFF ON ON OFF The switch settings for boards A B C and D in a four board configuration are shown in Table 2 5 Installation Warning Power off all units connected to your computer before you install the AMUX 64T If you have a 50 pin MIO board connect 50 pin ribbon cable from the 50 pin MIO board I O connector to either connector J1 or J2 on the AMUX 647T If you have a 68 pin MIO board connect a 6
58. fferential 10 V 5 10 V selectable on MIO board Each input should remain within 12 V of ground 35 V powered on 20 V powered off AMUX 64T User Manual Appendix A Specifications AMUX 64T Settling Times to 12 Bit Precision Settling time to 0 5 LSB 12 bit precision in us One AMUX 64T Board AT MIO 16E 2 AT MIO 16E 10 NB MIO 16 Gain FS 0 0 5 FS Oto FS FS Oto FS ES 5 3 9 8 1 5 3 9 8 14 12 2 5 3 9 8 5 5 3 9 8 10 6 4 9 8 20 15 20 6 5 10 9 50 7 6 11 10 100 9 8 12 11 20 20 500 50 50 Two AMUX 64T Boards AT MIO 16E 2 AT MIO 16E 10 NB MIO 16 Gain FS 0 0 5 FS Oto 5 FS Oto 5 6 5 10 8 1 6 5 10 8 25 12 2 6 5 10 8 5 7 6 10 9 10 7 6 11 9 35 15 20 7 7 11 10 50 8 7 13 12 100 11 10 15 14 60 30 500 70 60 AMUX 64T User Manual A 2 National Instruments Corporation Appendix A Specifications Four AMUX 64T Boards AT MIO 16E 2 AT MIO 16E 10 NB MIO 16 Gain FS 0to FS FS 0to FS FS 0to FS 5 8 8 13 12 1 8 8 13 12 25 12 2 9 8 13 12 5 9 9 13 12 10 9 9 13 12 50 30 20 11 10 14 13 50 11 11 15 14 100 14 13 17 16 70 50 500 110 100
59. figurations The AMUX 64T is designed so that up to four AMUX 64T boards can be daisy chained and connected to a single MIO board as shown in Figure 2 2 You can configure the five position switch labeled U12 according to the number of boards daisy chained together This switch is also used to assign distinct channel addresses to different AMUX 64T boards Table 2 5 lists the description and configuration of the switches Note In all of the following dual in line package DIP switch illustrations the dark shaded end of the switch is the end that you press down Table 2 5 Single and Multiple Board Configuration Jumper Description Configuration SW1 SW2 SW3 SW4 5 6 S single board OFF OFF OFF OFF OFF configuration factory Z setting U12 Set for U12 U12 two board m o z configuration Board A Board B U12 Set for U12 U12 U12 U12 four board Lame Rug LE configuration PE a a L a Board A Board B Board C Board D National Instruments Corporation 2 7 AMUX 64T User Manual Chapter 2 Configuration and Installation Mounting holes for standoffs or for mounting
60. figure Counter 1 to Control the MIO Board Scanning Clock 5 12 Set the SCANDIV Bit in MIO Command Register 1 5 12 AMUX 64T User Manual vi National Instruments Corporation Contents Appendix A Specifications Appendix B Customer Communication Glossary Index Figures Figure 1 1 The Relationship between the Programming Environment NI DAQ and Your 1 5 Figure 2 1 AMUX 64T Parts Locator 1 2 2 Figure 2 2 Daisy Chaining Multiple AMUX 64T 2 8 Figure 2 3 Cable Positioning for the AMUX 64T 2 11 Figure 3 1 AMUX 64T Signal Routing eese 3 4 Figure 4 1 Onboard Equivalent Circuit eese enne 4 2 Figure 4 2 Bias Return Resistor for DC Coupled Floating Source on Channel eate e eie deret ee 4 6 Figure 4 3 Normalized Frequency Response of Lowpass Filter 4 8 Figure 4 4 Lowpass Filter on Differential Channel 1 sess 4 0 Figure 4 5 Normalized Frequency Response of Highpass Filter 4 10 Figure 4 6 Highpass Filter on Differential Channel 1 5595995999 4 12 Figure 4 7 Attenuator for Use with Differential 4 13 Figure 5 1 AMUX 64T Block Diagram eene 5 2 Figure 5 2 Scann
61. for channel 0 is channel 32 and the signal return path for channel 31 is channel 63 Using the AMUX 64T for Thermocouple Measurements The AMUX 64T is equipped with a temperature sensor for thermocouple cold junction compensation Because thermocouple output voltages are typically a few millivolts you must use a high gain board any speed for best resolution Thermocouples may be measured in either differential or single ended configurations Differential connection tends to yield the best results but single ended connection allows twice as many thermocouples to be used on each AMUX 64T The cold junction compensation is accurate only if the temperature sensor reading is close to the temperature of the screw terminals Therefore when thermocouples are being read you should keep the AMUX 64T away from drafts or other temperature gradients such as those caused by heaters radiators fans very warm equipment and so on Selecting the Gain and Input Ranges Since thermocouple output voltages are very low a gain of 500 or 100 is usually necessary for best resolution You should set the input range on the MIO board to 5 V to improve resolution You can use these settings in all buta few cases such as a fairly high output thermocouple type that is being used at elevated temperatures Table 3 2 lists the voltage extremes from several popular thermocouple types Use it as a guide for determining the best gain and input range settings to us
62. ge of a thermocouple can be subdivided into several smaller ranges Each of the smaller ranges can then be approximated by a much lower order polynomial 1 6 third or fourth degree Further examples of polynomials including lower order polynomials for subdivided temperature ranges can be found in NIST Monograph 175 Temperature Electromotive Force Reference Functions and Tables for the Letter Designated Thermocouple Types Based on the ITS 90 Differential Measurements Connect the temperature sensor to channel 0 and channel 32 differential channel 0 by configuring jumper W1 as shown in Table 2 2 Temperature Sensor Selection Connect the thermocouples to the appropriate pairs of input channel screw terminals for example CH1 and CH33 CH2 and CH34 and so on Notice that some thermocouples such as those from Omega Engineering have red insulation on the negative terminal Check with the vendor to determine the output polarity of any particular thermocouple Since thermocouples are floating signal sources you must attach a bias return resistor between the negative channel and ground which is connected to the MIO board AIGND analog input ground pin The signal path of each channel has component locations for such resistors Refer to the Connecting Nonreferenced or Floating Signal Sources section of Chapter 4 Signal Conditioning for the resistor component locations For more information about signal sources and their connections see the
63. gle Board and Multiple Board Configurations seen 2 7 Single Board Configuration sess 2 9 Two Board Configuration 2 9 Four Board Configuration sess eee 2 9 Installation EOD RR 2 10 Power On Sequence ne E 2 11 Chapter 3 Signal Connections VO Connector eS 3 1 Differential Connections eiie diete teet e 3 5 National Instruments Corporation V AMUX 64T User Manual Contents Using the AMUX 64T for Thermocouple Measurements 3 5 Selecting the Gain and Input Ranges 3 5 Linearizing Data ice 3 6 Differential Measurements sssi 3 9 An Example of Using Thermocouples Differential or Single Ended 3 9 Procedure edes 3 10 Procedure 2 soe fed heeled PR RR 3 11 Ro E E rie 3 11 Single Ended Measurement sese eene 3 11 Using More Than One AMUXC 64T 3 12 Sources Of ETOT eL 3 12 Thermocouple Measurement Accuracies essen 3 13 Other Connection Considerations essent en
64. igger mode resistance capacitance Read signal external resistance referenced single ended Real Time System Integration G 4 National Instruments Corporation S SCXI SDK SERCLK SERDATIN SERDATOUT SLOTOSEL SPICLK SS STB T TTL typ UP BP Vin Vom VDC V EXT VI National Instruments Corporation G 5 Glossary seconds Signal Conditioning eXtensions for Instrumentation bus Software Developer s Kit Serial Clock signal Serial Data In signal Serial Data Out signal Slot 0 Select signal Serial Peripheral Interface Clock signal Slot select signal Strobe Input signal transistor transistor logic typical Unipolar bipolar bit volts positive negative input voltage common mode noise differential input voltage volts direct current external voltage virtual instrument measured voltage AMUX 64T User Manual Glossary Viis volts root mean square signal source W watts WRT Write signal AMUX 64T User Manual G 6 National Instruments Corporation Index A accuracy of thermocouple measurement 3 13 addressing AMUX 64T analog input channels A D conversions on single analog input channel 5 3 to 5 6 channel address mapping figure 5 6 channel selection table 5 4 multiple AMUX 64T board addressing table 5 5 scanning counter control bits figure 5 3 AMUX 64T block diagram 4 2 damaged equipment warning 3 1 features 1 1 optional
65. ing Channel Configurations You can configure the analog input channels of an MIO DAQ board for one of three input modes differential input referenced single ended input or nonreferenced single ended These modes may be referred to as DIFF RSE and NRSE input modes respectively As described in Chapter 2 Configuration and Installation of your MIO user manual the input configuration of the MIO board depends on the type of signal source There are two types of signal sources nonreferenced or floating signals and ground referenced signals To measure floating signal sources configure the MIO board for referenced single ended input or differential input with bias resistors To measure ground referenced signal sources configure the MIO board for non referenced single ended input or differential input Both types of signal sources and the recommended methods for MIO board connection are discussed as follows Connecting Nonreferenced or Floating Signal Sources A floating signal source is a signal source that is not connected in any way to the building ground system but has an isolated ground reference point If an instrument or device has an isolated output that instrument or device falls into the floating signal source category Some examples of floating signal sources are outputs for the following thermocouples transformers battery powered devices optical isolators and isolation amplifiers You must tie the ground reference of a flo
66. ing Counter Control Bits esee 5 3 Figure 5 3 AMUX 64T Channel Address Mapping 5 6 Figure 5 4 Two Level Multiplexer Arrangement Showing Channel 9 Selected 5 7 Figure 5 5 Scanning Order for Different AMUX 64T Board Configurations 5 9 Tables Table 2 1 Power Supply Selection 2 3 Table 2 2 Temperature Sensor Selection seen 2 3 Table 2 3 Shield Sel etiofis etre eer ge 2 4 Table 2 4 MIO Board Power Budget sese 2 5 National Instruments Corporation Vii AMUX 64T User Manual Contents Table 2 5 Single and Multiple Board Configuration eee sese 2 7 Table 2 6 Channel Ranges for Multiple AMUX 64T 2 8 Table 2 7 U12 Switch Settings for Two Board Configuration 2 9 Table 2 8 U12 Switch Settings for Four Board Configuration 2 10 Table 3 1 Pin Mapping for I O Connectors J1 J2 and J42 3 2 Table 3 2 Thermocouple Voltage Output Extremes 3 6 Table 3 3 NIST Polynomial Coefficients eese 3 8 Table 3 4 Thermocouple Measurement 3 13 Table 4 1 Component Positions in Each Channel sees 4 2 Table 5 1 AMUX 64T Channel Selection
67. ive program development software packages for data acquisition and control applications Lab VIEW uses graphical programming whereas LabWindows enhances traditional programming languages Both packages include extensive libraries for data acquisition instrument control data analysis and graphical data presentation LabVIEW currently runs on four different platforms AT MC EISA computers running Microsoft Windows NEC computers running Windows the Macintosh platform and the Sun SPARCstation platform 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 Libraries are functionally equivalent to the NI DAQ software except that the SCXI functions are not included in the LabVIEW software for Sun LabWindows has two versions LabWindows for DOS is for use on PCs running DOS and LabWindows CVI is for use on PCs running Windows and for Sun SPARCstations LabWindows CVI features interactive graphics a state of the art user interface and uses the ANSI standard C programming language The LabWindows Data Acquisition Library a Series of functions for using LabWindows with National Instruments DAQ hardware is included with the NI DAQ software kit The LabWindows Data Acquisition libraries are functionally equiv
68. ized 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 Bold italic text denotes a note caution or warning Italic text denotes emphasis a cross reference or an introduction to a key concept Refers to MIO and AI boards such as the AT MIO 16XE 10 NB MIO 16 NEC AI 16E 4 and AT AI 16XE 10 boards Refers to the Micro Channel Series computers Refers to multichannel I O DAQ boards that have MIO in their names such as the AT MIO 16 AT MIO 16D and NEC MIO 16E 4 Text in this font denotes text or characters that you should literally enter from the keyboard programming examples and syntax examples This font is also used for device names functions variables filenames and extensions and for statements and comments taken from program code NB refers to the NuBus series computers PC refers to the IBM PC XT the IBM PC AT and compatible computers X National Instruments Corporation About This Manual National Instruments Documentation The AMUX 64T User Manual is one piece of the documentation set for your system You could have any of several types of documentation depending on the hardware and software in y
69. jumper to the NC position keeps the AMUX 64T AIGND isolated from the rack Jumper W3 connects the shield of the 68 position connector to the rack mount kit Setting this jumper to the CABLE SHLD position connects the shield of the 68 position connector to the metal standoff in the lower left corner of the board Setting this jumper to the NC position keeps the computer chassis isolated from the rack Both jumpers ground configurations may or may not be desired for your application For most applications you should not connect the grounds together with these jumpers Connecting jumper W3 may cause ground currents to flow between the computer chassis and the rack mount chassis These currents are likely to couple noise into the analog signals in the cabling Connecting jumper W2 may cause ground currents to flow between the MIO board AIGND signal measurement ground and the rack mount chassis These currents directly interfere with measurements made with the analog signals especially when the MIO board is in RSE mode If the rack mount chassis is floating that is not earth grounded you should ground it Ground the rack via a ground strap or other recommended ways You may ground it using jumper W3 In general you will get the best results if all grounds and shields have exactly one conduction path to earth ground 2 6 National Instruments Corporation Chapter 2 Configuration and Installation Single Board and Multiple Board Con
70. level programming 1 6 requirements for getting started 1 2 resistance capacitance RC filters See highpass filters lowpass filters S scanning See channel scanning screw terminals 63 never connecting signals to caution 3 1 Seebeck coefficient 3 6 settling times to 12 bit precision A 2 to A 3 four AMUX 64T boards table A 3 single AMUX 64T board table A 2 two AMUX 64T boards table A 2 shield selection jumper settings table 2 4 supplementary information 2 6 signal conditioning 4 1 to 4 14 analog input 4 1 to 4 4 component positions in each channel table 4 2 to 4 4 onboard equivalent circuit figure 4 2 application notes 4 4 to 4 14 AMUX 64T User Manual l 4 building attenuators voltage dividers 4 12 to 4 14 attenuators for use with differential inputs figure 4 13 input voltage greater than 42 V warning 4 12 building highpass filters 4 10 to 4 12 highpass filter on differential channel 1 figure 4 12 normalized frequency response figure 4 10 building lowpass filters 4 8 to 4 9 lowpass filter on differential channel 1 figure 4 9 normalized frequency response figure 4 8 to 4 9 channel configurations 4 5 connecting ground referenced signal sources 4 7 differential inputs 4 7 single ended inputs 4 7 connecting nonreferenced or floating signal sources 4 5 to 4 6 differential inputs 4 5 to 4 6 single ended inputs 4 6 soldering and desoldering on AMUX 64T
71. m Table 3 3 you can calculate that the temperature is 198 C 3 10 National Instruments Corporation Chapter 3 Signal Connections Procedure 2 1 Read the voltage from the temperature sensor channel 0 If you are using NI DAQ you can use the Read and AI_Scale functions to do the reading This voltage is 10 mV C so the gain should be either 1 or 10 10 for the best resolution Multiply the voltage by 100 to get the AMUX 64T temperature in degrees Celsius For example if the reading is 0 25 V the AMUX 64T is at 25 2 Read the voltages any thermocouple channels If you are using NI DAQ you can use the AT Read and Scale functions to read each channel or you can use the SCAN functions to scan all the channels at once If you use the SCAN functions use a sample interval of 100 us between channels For the example given the gain is at 500 for channel 1 Other thermocouple types may require other gains 3 Translate the reading into a temperature using either a look up table or a polynomial such as one from Table 3 3 For example when reading 9 39 mV from a type J thermocouple the temperature is 175 C 4 Add the cold junction temperature from step 1 to the temperature obtained in the previous step This result is the temperature at the measuring end of the thermocouple For the example given the temperature is 175 C 25 C 200 C Comments Procedure is more accurate but it requires two t
72. ments Corporation Chapter 5 Theory of Operation and Register Level Programming For example if one AMUX 64T board is used channels 0 through 3 on the AMUX 64T are automatically scanned whenever channel 0 on the MIO board is selected in the scan sequence If two AMUX 64T boards are used channels 0 through 3 board A and channels 64 through 67 board B are automatically scanned If four AMUX 64T boards are used channels 0 through 3 board A channels 64 through 67 board B channels 128 through 131 board C and channels 192 through 195 board D are automatically scanned If the MIO board is programmed with a sequential channel scan sequence 0 through 7 or 0 through 15 the AMUX 64T channels are scanned from top to bottom in the order given in Table 5 3 If only one AMUX 64T board is used the channels are scanned in the order 0 through 63 for single ended configuration The scanning order becomes complex only when more than one AMUX 64T board is used During interval scanning the number of channels scanned during an interval is four times the channel scan sequence for one AMUX 64T board eight times for two AMUX 64T boards and sixteen times for four AMUX 64T boards Programming Channel Scanning with the AMUX 64T To program the MIO board to conduct a scanning operation with the AMUX 64T the following steps must be added to the instructions for programming multiple A D conversions with channel scanning given in Chapter 4 of
73. n ComponentWorks Conventional LabVIEW Programming Environment LabWindows CVI or VirtualBench NI DAQ Driver Software Personal kard Computer or Workstation Figure 1 1 The Relationship between the Programming Environment NI DAQ and Your Hardware The National Instruments PC AT MC DAQCard and DAQPad Series DAQ hardware is packaged with NI DAQ software for PC compatibles NI DAQ software for PC compatibles comes with language interfaces for Professional BASIC QuickBASIC Visual Basic Borland Turbo Pascal Turbo C Borland C Microsoft Visual C and Microsoft C for DOS and Visual Basic Turbo Pascal Microsoft C with SDK and Borland C for Windows and Microsoft Visual C for Windows NT You can use your AMUX 647 together with other PC AT MC EISA DAQCard and DAQPad Series DAQ and SCXI hardware with NI DAQ software for PC compatibles The National Instruments NB Series DAQ boards are packaged with NI DAQ software for Macintosh NI DAQ software for Macintosh comes with language interfaces for MPW C THINK C Pascal and Microsoft QuickBASIC Any language that uses Device Manager Toolbox calls can access NI DAQ software for Macintosh You can use NB Series DAQ boards and SCXI hardware with NI DAQ software for Macintosh National Instruments Corporation 1 5 AMUX 64T User Manual Chapter 1 Introduction The National Instruments SB S
74. o 4 6 signal connections 3 5 differential measurement of thermocouples example 3 9 to 11 procedure 3 9 documentation conventions used in manual x National Instruments documentation xi organization of manual ix x related documentation xi E electronic support services B 1 to B 2 e mail support B 2 environment specifications A 4 equipment optional 1 7 errors in thermocouple measurement sources of 3 12 F fax and telephone support numbers B 2 Fax on Demand support B 2 filters See highpass filters lowpass filters floating signal sources 4 5 to 4 6 bias return resistor for DC coupled floating source figure 4 6 differential inputs 4 5 to 4 6 single ended inputs 4 6 FTP support B 1 National Instruments Corporation G gain and input ranges for thermocouples selecting 3 5 to 3 6 ground referenced signal sources differential inputs 4 7 single ended inputs 4 7 H highpass filters building 4 10 to 4 12 highpass filter on differential channel 1 figure 4 12 normalized frequency response figure 4 10 input modes configuring 4 5 installation cable positioning figure 2 11 instructions 2 10 power on sequence 2 11 unpacking the AMUX 64T 1 2 connector J1 J2 and J42 3 1 to 3 4 AMUX 64T signal routing figure 3 4 pin mapping for J1 J2 and J42 table 3 2 to 3 3 J jumpers and switches See configuration L LabVIEW and LabWindows application software
75. o 500 kS s on ISA computers and up to 1 MS s on EISA computers NI DAQ includes a Buffer and Data Manager that uses sophisticated techniques for handling and managing data acquisition buffers so that you can simultaneously acquire and process data NI DAQ functions for the DAQCard DIO 24 can transfer data using interrupts or software polling With the NI DAQ Resource Manager you can simultaneously use several functions and several DAQ devices The Resource Manager prevents multiple device contention over DMA channels interrupt levels and RTSI channels NI DAQ can send event driven messages to DOS Windows or Windows NT applications whenever a user specified event occurs Thus polling is eliminated and you can develop event driven data acquisition applications An example of an NI DAQ user event is when a specified digital I O pattern is matched NI DAQ also internally addresses many of the complex issues between the computer and the DAQ hardware such as programming the PC interrupt 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 Figure 1 1 illustrates the relationship between NI DAQ and LabVIEW and LabWindows You can see that the data acquisition parts of LabVIEW and LabWindows are functionally equivalent to the NI DAQ software AMUX 64T User Manual 1 4 National Instruments Corporation Chapter 1 Introductio
76. oard channel SCANCLK increments the AMUX 64T scanning counter on every A D conversion and Counter 1 on the MIO board must be used to divide the onboard scanning counter clock by four The Single Board Configuration section of Figure 5 5 shows the scanning order for the four AMUX 64T channels multiplexed to MIO board channel 0 If two AMUX 64T boards are attached to the MIO board eight AMUX 64T channels must be scanned for every MIO board input channel For example channels 0 through 3 on AMUX 64T board A and channels 64 through 67 on AMUX 64T board B are multiplexed together into MIO board channel 0 The Two Board Configuration section of Figure 5 5 shows the order in which these eight AMUX 64T channels are scanned Observe that the first four channels on board A are scanned first followed by the first four channels on board B If four AMUX 64T boards are attached to the MIO board 16 AMUX 64T channels must be scanned for every MIO board input channel For example channels 0 through 3 on AMUX 64T board A channels 64 through 67 on AMUX 64T board B channels 128 through 131 on AMUX 64T board C and channels 192 through 195 on board D are multiplexed together into MIO board channel 0 The Four Board Configuration section of Figure 5 5 shows the order in which these 16 AMUX 64T channels are scanned the first four channels on board A are scanned first followed by the first four channels on board B the first four channels on board C and finally
77. olynomials are by nature approximations of the true thermocouple output The linearization error is dependent on the degree of polynomial used Table 3 3 lists the linearization errors for the NIST polynomials Measurement error is the result of inaccuracies in the MIO board These include gain and offset errors If the board is properly calibrated the offset error should be zeroed out The only remaining error is a gain error of 0 08 of full range see the MIO board specifications If the input range is 10 V and the gain is 500 gain error will contribute 0 0008 x 20 mV or 16 LV of error If the Seebeck coefficient of a thermocouple is 32 this measurement error will add 0 5 C of uncertainty to the measurement 3 12 National Instruments Corporation Chapter 3 Signal Connections For best results use a well calibrated MIO board so that you can ignore offsets You can eliminate offset error however by grounding one channel on the AMUX 64T and measuring it This value is the offset of the MIO board and it can then be subtracted in software from all other readings For the best results you should use an average of many readings about 100 or so When you take these measures typical accuracies are about 2 C Finally thermocouple wire error is caused by inhomogeneities in the thermocouple manufacturing process These errors vary widely depending on the thermocouple type and even the gauge of wire used but a value of
78. onfiguration CHO and CH32 position Use this setting to select CHO and CH32 factory setting Temp position Use this setting to select the temperature sensor CHO CH32 Temp Channel 0 and 32 Selected Factory Setting CHO CH32 Temp Temperature Sensor Selected National Instruments Corporation 2 3 AMUX 64T User Manual Configuration and Installation Chapter 2 Configuration and Installation Table 2 3 Shield Selection Jumper Description Configuration No Connect position Use this setting Chassis to disconnect the AMUX 64T analog Y ground from the shield of a rack mounted chassis factory setting NC w2 A AIGND AIGND position Use this setting to Chassis connect the AMUX 64T analog ground to the shield of a rack mounted chassis w2 AIGND No Connect position Use this setting W3 to disconnect the AMUX 64T 68 pin Chassis connector shield from the shield of a w3 rack mounted chassis factory setting Js NC T Cable Shield CABLE SHLD position Use this Chassis setting to connect the AMUX 64T 68 pin connector shield to the shield of w3 55 rack mounted chassis JIS Shield Connected Note Supplem
79. onnected to channels 0 and 32 These two channels on the other boards are then free for more thermocouples If the AMUX 64T boards are not at approximately the same temperature you should use the temperature sensor on each AMUX 64T Using the temperature sensors on each board reduces the chance of cold junction compensation error but it does increase software overhead and reduce the number of channels available for general use If you use two AMUX 64T boards the sensors will appear at channel 0 for board A and channel 64 for board B If you use four AMUX 64T boards the sensors will appear at channel 0 for board A channel 64 for board B channel 128 for board C and channel 192 for board D see the Single Board and Multiple Board Configurations section in Chapter 2 Configuration and Installation There are several major sources of error when making thermocouple measurements with the AMUX 64T and an MIO board These sources of error are compensation linearization measurement and thermocouple wire errors Compensation error can arise from two sources inaccuracy of the temperature sensor and temperature differences between the sensor and the screw terminals The sensor on the AMUX 64T is specified to be accurate to 1 C You can minimize temperature differences between the sensor and the screw terminals by keeping the AMUX 64T away from drafts heaters warm equipment and so on Linearization error is a consequence of the fact that the p
80. ormation AMUX 64T User Manual 3 14 National Instruments Corporation Signal Conditioning Analog Input This chapter discusses signal conditioning and describes how to build systems such as filters and attenuators for passive analog input signal conditioning Each differential analog input has seven open positions for signal conditioning components Six of these positions are designated as resistors and one is designated as a capacitor The board is shipped with jumpers in two positions for each input The equivalent circuit of one input is shown in Figure 4 1 You can use the board when the MIO board is configured for both 16 single ended inputs and eight differential inputs For thermocouple and other low level applications you can obtain best results when using differential inputs For specific applications illustrating signal conditioning with both single ended and differential inputs refer to Application Notes later in this chapter National Instruments Corporation 4 1 AMUX 64T User Manual Chapter 4 Signal Conditioning ACH33 ACH1 SIGNAL SIGNAL e SCREW 5 TERMINALS 5 M pou Jumpers Installed at Factory B as m 2 0 ADM ML AIGND E AIGND Reg iF 867 SE Y G Y ACH aer en on MIO board Fig
81. other boards in the system Temperature Sensor Table 2 2 shows the positions for jumper W1 The AMUX 64T is equipped with an onboard temperature sensor for use with thermocouple cold junction compensation This sensor is a National Semiconductor LM 35CZ that provides a voltage output of 10 m V C with an accuracy of 1 C The sensor is jumper selected on differential input channel 0 National Instruments Corporation 2 5 AMUX 64T User Manual Chapter 2 Configuration and Installation AMUX 64T User Manual Configure the host MIO board for differential inputs if you plan to use this temperature sensor Use jumper W1 to select either the temperature sensor or the external screw terminals as the input source for differential channel 0 The AMUX 64T is shipped from the factory with the jumpers set so that CHO and CH32 are connected to the terminal block the temperature sensor is not selected Shield Selection The AMUX 64T is shipped from the factory with the jumpers set so that AIGND and CABLE SHLD are disconnected from CHASSIS Table 2 3 shows the jumper W2 and jumper W3 settings The AMUX 64T has two optional connections that are relevant when using a rack mount kit to mount the AMUX 64T jumpers W2 and W3 Jumper W2 connects the analog input ground AIGND to the rack mount kit Setting this jumper to the AIGND position connects the AIGND signal to the metal standoff in the lower left corner of the board Setting this
82. our system Use the different types of documentation you have as follows e Your DAQ hardware user manuals These manuals have detailed information about the DAQ hardware that plugs into or is connected to your computer Use these manuals for hardware installation and configuration instructions specification information about your DAQ hardware and application hints e Software documentation Examples of software manuals you may have are the LabVIEW and LabWindows CVI Virtual Bench Component Works Measure and NI DAQ documentation After you set up your hardware system use either your application software documentation 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 e Accessory installation guides or manuals TIf you are using accessory products read the terminal block and cable assembly installation guides or 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 Related Documentation The following document contains information you may find helpful as you read this manual e NIST Monograph 175 Temperature Electromotive Force Reference Functions and Tables for the Letter Designated Thermocouple Types Based on the ITS 90 National Institute of Standards and Technology
83. ows to control your board you should not need the programming information in Chapter 5 Theory of Operation and Register Level Programming Chapter 5 Theory of Operation and Register Level Programming contains low level programming details such as register maps bit descriptions and register programming hints that you will need only for register level programming AMUX 64T User Manual 1 6 National Instruments Corporation Chapter 1 Introduction Optional Equipment Contact National Instruments to order any of the following optional equipment e 8 50 I O connector 50 screw terminals with 0 5 or 1 0 m cable e SCB 68 I O connector 68 screw terminals with 0 5 or 1 0 m cable e 596868 shielded cable assembly with 1 2 5 or 10 m cable e 596850 shielded cable assembly with 1 2 5 or 10 m cable e R68681 m ribbon cable assembly e 6850 1 m ribbon cable assembly e Rack mount kit with acrylic plastic cover single or double height e Rack mount kit with metal wraparound cover single or double height For more information about optional equipment available from National Instruments refer to your National Instruments catalog or call the office nearest you National Instruments Corporation 1 7 AMUX 64T User Manual Configuration and Installation This chapter describes the configuration and installation of your AMUX 64T The topics discussed include switch and jumper configuration connection of the A
84. resulting from an incorrect ground reference NEVER connect a signal to screw terminals CH0 CH63 that violates their overvoltage protection limits When the AMUX 64T is powered on the screw terminals CH0 CH63 overvoltage protection is 35 V when the AMUX 64T is powered off overvoltage protection is 20 V National Instruments Corporation 4 7 AMUX 64T User Manual Chapter 4 Signal Conditioning Building Lowpass Filters You can easily install simple resistance capacitance RC lowpass filters in the AMUX 64T board on any differential input channel The filters are useful for accurate measurement and noise rejection By substituting resistance and capacitance values into the following equation hereafter referred to as equation 4 1 you can calculate a simple one pole RC filter to have 3 dB point f or cutoff frequency _ 1 x fc RRO 4 1 The frequency response rolls off at a rate of 20 dB per decade of increase thereafter A Bode plot of the amplitude versus normalized frequency is shown in Figure 4 3 Amplitude dB 1 o 20 0 01 T 40 0 001 60 0 0001 1 80 0 1 1 10 100 1 000 10 000 f Normalized Frequency Figure 4 3 Normalized Frequency Response of Lowpass Filter When measuring low frequency signals about 4 Hz if you have 400 Hz noise on your inputs you can add a lowpass filter with a cutoff frequency of 4 Hz The 400 Hz noise then
85. t AMUX 64T User Manual Figure 4 2 Bias Return Resistor for DC Coupled Floating Source on Channel 1 Single Ended Inputs When measuring floating signal sources you should configure the MIO board to supply a ground reference Therefore you should configure the MIO board for referenced single ended input In this configuration the negative input of the MIO board instrumentation amplifier is tied to the analog ground Therefore you should use the AMUX 64T board in its factory configuration In the factory configuration jumpers are in the two series positions E and F see Table 4 1 In this configuration you should tie all of the signal grounds to AIGND You can build signal conditioning circuitry such as filters and attenuators described in Building Lowpass Filters Building Highpass Filters and Building Attenuators Voltage Dividers later in this chapter in the open component positions 4 6 National Instruments Corporation Chapter 4 Signal Conditioning Connecting Ground Referenced Signal Sources N Caution A grounded signal source is connected in some way to the building system ground therefore the signal source is already connected to a common ground point with respect to the DAQ board assuming the host computer is plugged into the same power system Nonisolated outputs of instruments and devices that plug into the building power system fall into this category Differential Inputs If the MIO DAQ bo
86. the first four channels on board D 5 8 National Instruments Corporation Chapter 5 Theory of Operation and Register Level Programming Single Board Configuration Scanning Order so 0 CH1 1 Board A CH2 7 CHO MIO Board cH Two Board Configuration Scanning Order CHO CH1 1 Board A CH2 E CHO MIO Board 0837 23 60 64 CH1 65 Board B CH2 66 p CH3 67 scs mE 6 o Four Board Configuration Scanning Order CHO 6700 CH1 Board A 6 0 1 CH2 CHO Board CH3 6 gt 2 64 Board B CH1 65 a 5 CH2 66 CHS 67 po CHO 128 159 5 Board 13 fe CH3 131 a o CH0 192 _ CH1 193 Board 0 194 o F CH3 195 Pah Channel Number as Addressed from MIO Board Channel Number as Labeled on AMUX 64T Figure 5 5 Scanning Order for Different AMUX 64T Board Configurations National Instruments Corporation 5 9 AMUX 64T User Manual Chapter 5 Theory of Operation and Register Level Programming Scanning Order The order in which channels are scanned depends on the contents of the mux gain memory The mux gain memory on the MIO board can be loaded with a sequence to scan the MIO onboard channels in any order Figure 5 5 shows the scanning order on the AMUX 64T Table 5 3 shows the order in which the
87. 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 data 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 AMUX 64T User Manual Fax on Demand Support Fa
88. the user manual that came with your MIO board These steps can be added any time before initiating the A D conversions Initialize the AMUX 64T Scanning Counter The DOUTENO bit in the MIO board Command Register 2 this bit has different names depending on your MIO board must be set in order to load the AMUX 64T scanning counter To initialize the AMUX 64T scanning counter use the following programming sequence 1 Write 0 to digital I O port A 2 Write to the External Strobe Register to load 0 into the AMUX 64T scanning counter National Instruments Corporation 5 11 AMUX 64T User Manual Chapter 5 Theory of Operation and Register Level Programming Configure Counter 1 to Control the MIO Board Scanning Clock Counter 1 on the MIO board is used to divide the onboard scanning clock controlling the scanning counter so that the onboard multiplexers switch at a slower rate than the AMUX 64T multiplexers To program counter 1 use the following programming sequence All operations are 16 bit write operations All values given are hexadecimal e Write FFO1 to the Am9513 Command Register to select the Counter 1 Mode Register e Write 0325 hex to the Am9513 Data Register to store the Counter 1 mode value e Write FF09 to the Am9513 Command Register to select the Counter 1 Load Register Write the divide down value to the Am9513 Data Register to load counter 4 The divide down values are as follows One AMUX 64T board 4
89. tren 3 14 Chapter 4 Signal Conditioning Amalos Input onm t eR REOR ee Hr RR FORE reri E eS 4 1 Application Notes oce RR CHEER PERIERE EE 4 4 Soldering and Desoldering on the AMUX 64T 4 4 Channel Configurations nenne 4 5 Connecting Nonreferenced or Floating Signal 4 5 Differential 4 5 Single Ended 180005 e iTi 4 6 Connecting Ground Referenced Signal Sources sss 4 7 Differential Inputs iere mtem irem 4 7 Single Ended Inputs 4 7 Building Lowpass Filters enne 4 8 Building Highpass 11 6 5 4 10 Building Attenuators Voltage Dividers eese 4 12 Chapter 5 Theory of Operation and Register Level Programming Functional Overview itt e os ud i t 5 1 How to Address AMUX 64T Analog Input Channels eese 5 3 A D Conversions on a Single AMUX 64T Analog Input Channel 5 3 Automatic Channel Scanning with the AMUX 64T essen 5 7 Scanning Order nee t ee e P RU e Ere rers 5 10 Programming Channel Scanning with the 417 64 sese 5 11 Initialize the AMUX 64T Scanning Counter eese 5 11 Con
90. ure 4 1 Onboard Equivalent Circuit The components are numbered differently for each channel Table 4 1 lists the components in each channel and their correspondence to the circuit shown in Figure 4 1 Table 4 1 Component Positions in Each Channel Channel Positions in Figure 4 1 Differential Single Channel A B G 0 0 32 R2 R3 R4 R65 R66 C3 1 1 33 R5 R6 R7 R8 R67 R68 C4 2 2 34 R9 R10 R11 R12 R69 R70 C5 3 3 35 R13 R14 R15 R16 R71 R72 C6 4 4 36 R17 R18 R19 R20 R73 R74 C7 5 5 37 R21 R22 R23 R24 R75 R76 C8 AMUX 64T User Manual 4 2 National Instruments Corporation Chapter 4 Signal Conditioning Table 4 1 Component Positions in Each Channel Continued Channel Positions in Figure 4 1 Differential Single Channel A B G 6 6 38 R25 R26 R27 R28 R77 R78 C9 7 7 39 R29 R30 R31 R32 R79 R80 C10 8 8 40 R33 R34 R35 R36 R81 R82 11 9 9 41 R37 R38 R39 R40 R83 R84 C12 10 10 42 R41 R42 R43 R44 R85 R86 C13 11 11 43 R45 R46 R47 R48 R87 R88 C14 12 12 44 R49 R50 R51 R52 R89 R90 C15 13 13 45 R53 R54 R55 R56 R91 R92 C16 14 14 46 R57 R58 R59 R60 R93 R94 C17 15 15 47 R61 R62 R63 R64 R95 R96 C18 16 16 48 R129 R130 R131 R132 R97 R98 C37 17 17 49 R133 R134 R135 R136 R99 R100 C38 18 18 50 R137 R138 R139 140 R101 102 C39 19 19 51 R14
91. voltage change per degree of temperature change can vary by a factor of three or more over the operating temperature range of some thermocouples For this reason the temperature from thermocouple voltages must either be approximated by often complex polynomials or matched against a look up table The polynomial approach is easier to use but it trades measurement time for memory usage The polynomials are in the following form _ 2 T agta xtayx a x where x is the thermocouple voltage in volts T is the temperature difference between the measuring end and the AMUX 64T screw terminals in degrees Celsius and a through a are coefficients that are specific to each thermocouple type To speed computation time a polynomial should be 3 6 National Instruments Corporation Chapter 3 Signal Connections computed in nested form Consider the following fourth order polynomial 2 3 4 T dg t GjX Q X 44x If this polynomial is evaluated as it is written several extra multiplications will be performed to raise x to the various powers If the polynomial is instead written as follows T ag x a xaj and evaluated this way no powers are computed and execution proceeds much faster Table 3 3 lists the National Institute of Standards and Technology NIST polynomial coefficients for several popular thermocouples National Instruments Corporation 3 7 AMUX 64T User Manual enue 195
92. x 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 AMUX 64T 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 9 640 0085 08 730 49 70 056 200 51 51 02 377 1200 01635 523545 512 795 8248 B 2 Fax 03 9
93. 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 t0 Technical Publications Faxt0 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 n nano 10 9 u micro 10 6 m milli 10 3 k kilo 103 M mega 106 Numbers Symbols P degrees gt greater than gt greater than or equal to lt less than negative of or minus Q ohms percent plus or minus positive of or plus 5 V 5 Volts signal A A amperes ACH lt 0 7 gt Analog Channel 0 through 7 signals ACK Acknowledge Input signal A D analog to digital National Instruments Corporation G 1 AMUX 64T User Manual Glossary ADC AGND AISENSE AIGND ANSI AWG CLKB1 CLKB2 cm CMOS CNTINT D D A D A DAC DAC OUTPUT UPDATE DACWRT DACOOUT DACIOUT DAQ DAQD A DATA dB DC DGND DIFF AMUX 64T User Manual analog to digital converter Analog Ground signal Analog Input Sense Analog Input Ground signal American National Standards Institute American Wire Gauge Celsius Counter B1 B2 Clock signals centimeters complementary metallic oxid
94. yright 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 ComponentWorks LabVIEW Measure natist com NI DAQ RTSI SCXI and VirtualBench are trademarks of National Instruments Corporation Product and company names mentioned herein 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

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