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National Instruments SCXI-1121 manual

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Table of contents for the manual

  • Page 1

    SCXI ™ SCXI-1121 User Manual Four-Channel Isolated Universal Transducer Module for Signal Conditioning SCXI-1121 User Manual September 1999 Edition Part Number 3204 26C-01[...]

  • Page 2

    Worldwide Technical Support and Product Info rmation www.natinst.com National Instruments Corporate Headquarters 11500 North Mopac Expressway Austin, Texas 78759-3504 USA Tel: 512 794 0100 Worldwide Offices Australia 03 9879 5166, Austria 0662 45 79 90 0, Belgium 02 757 00 20, Brazil 011 284 5011, Canada (Calgary) 403 274 9391, Canada (Ontario) 905[...]

  • Page 3

    Important Information Warranty The SCXI-1121 is warranted against defec ts in materials and workmanshi p for a period of one year from the date of shipment, as evidenced by receipts or other documentation. National Instruments will, at its option, repair or replace equipment that proves to be defect ive d uring the warrant y pe riod. T hi s wa rran[...]

  • Page 4

    © National Instruments Corporation v SCXI-1121 User Manual Contents About This Manual Conventions ............ ........... ........... ............... ........... ........... ........... ............... ........... ....... x i Related Documentation ............ ........... ........... ... ........... ... ............ ........... ... ........... ..[...]

  • Page 5

    Contents SCXI-1121 User Manual vi www.natinst.com Chapter 3 Theory of Operation Functional Overview ............. ........... ............ .............. ........... ........... ............... ........... ... 3-1 SCXIbus Connector ................. ........... ... ........... ............ ... ........... ........... ... ...... 3-3 SCXIbus Connecto[...]

  • Page 6

    Contents © National Instruments Corporation vii SCXI-1121 User Manual 2. Module Programming ................................................................... 5-10 3. Programming the Slot 0 Hardscan Circuitry ................. .............. .. 5-13 4. Acquisition Enable, Triggering, and Servicing ...................... ....... 5-14 Scanning Exam[...]

  • Page 7

    Contents SCXI-1121 User Manual viii www.natinst.com Figures Figure 2-1. SCXI-1121 General Parts Locator Diagram ............................. ............ 2-2 Figure 2-2. SCXI-1121 Detailed Parts Locator Diagram .......................... .............. 2-3 Figure 2-3. SCXI-1121 Front Connector Pin Assignment ........................ ..............[...]

  • Page 8

    Contents © National Instruments Corporation ix SCXI-1121 User Manual Figure E-2. SCXI-1180 Rear Connections ............................................................... E-9 Figure E-3. SCXI-1180 Front Panel Installation ..................... ............... .............. .... E-10 Figure E-4. Cover Removal ........... .............. ..........[...]

  • Page 9

    © National Instruments Corporation xi SCXI-1121 User Manual About This Manual This manual describes the electrical and mechanical aspects of the SCXI-1121 and contains information concerning its operation and programming. The SCXI-1121 is a member of the National Instruments Signal Conditioning eXtensions for Instrumentation (SCXI) Series for the [...]

  • Page 10

    About This Manual SCXI-1121 User Manual xii www.natinst.com monospace T ext in this font denotes text or characters that you should enter from the ke yboard, sections of code, programming examples, and syntax examples. This font is also used for the proper names of d isk dri ves, paths, directories, programs, subprograms, subroutines, device names,[...]

  • Page 11

    © National Instruments Corporation 1-1 SCXI-1121 User Manual 1 Introduction This chapter describes the SCXI-1121; lists the contents of your SCXI-1121 kit; describes the optio nal software, option al equipment, and custom cables; and explains how to unpack the SCXI-1121 kit. The SCXI-1121 consists of four isolated input chan nels and four isolated[...]

  • Page 12

    Chapter 1 Introduction SCXI-1121 User Manual 1-2 www .natinst.com What Y our Kit Should Contain The contents of the SCXI-1121 kit (part number 776572-21) are listed as follows: If your kit is mi ssing an y of the components, contact Nati onal Instruments . Optional Software This manual contains complete inst ruct ions for directly pro gram mi ng th[...]

  • Page 13

    Chapter 1 Introduction © National Instruments Corporation 1-3 SCXI-1121 User Manual for DOS and V isual Basic, T urbo Pascal, Microsoft C with SDK, and Borland C++ for W indo ws. NI-D A Q software for DOS/W indo ws/LabW indows is on high-density 5.25 in. and 3.5 in. diskettes. Y ou can use the SCXI-1121, together with the Lab-LC or NB Series data [...]

  • Page 14

    Chapter 1 Introduction SCXI-1121 User Manual 1-4 www .natinst.com Optional Equipment Equipment Part Number NB6 cable 0.5 m 181305-01 1.0 m 181305-10 SCXI-1320 front terminal block 776573-20 SCXI-1321 of fs et-null and shunt-calibration terminal block 776573-21 SCXI-1328 high-accuracy isothermal terminal block 776573-28 SCXI-1330 32-pin connector-an[...]

  • Page 15

    Chapter 1 Introduction © National Instruments Corporation 1-5 SCXI-1121 User Manual Refer to the Signal Connections section in Chapter 2, Configuration and Installation , and to Appendix E, SCXI-1121 Cabling , for additional information on cabling, connectors, and adapters. Custom Cables The SCXI-1121 rear signal connector is a 50-pin male ribbon-[...]

  • Page 16

    Chapter 1 Introduction SCXI-1121 User Manual 1-6 www .natinst.com Unpacking Your SCXI-1121 module is shipped in an anti st atic package to prevent electrostatic damage to the modu le. Several components on the module can be damaged by electrostatic discharge. To avoid such damage in handling the module, take the following precautions. • T ouch th[...]

  • Page 17

    © National Instruments Corporation 2-1 SCXI-1121 User Manual 2 Configuration and Installation This chapter describes the SCXI-1121 jumper configurations, installation of the SCXI-1121 into the SCXI chassis, signal connections to the SCXI-1121, and cable wiring. Module Configuration The SCXI-1121 contains 49 jumpers that are shown in the parts loca[...]

  • Page 18

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-2 www .natinst.com Figure 2-2. SCXI-1121 Detailed Parts Locator Diagram The jumpers are used as follo ws: • Fixed jumpers – On Revision A and B modules, jumper W32 is unused and should not be connected. – Jumper W45 is reserved and should not be reconfigured. – On Re vision A [...]

  • Page 19

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-3 SCXI-1121 User Manual – Jumpers W3, W19, W29, and W41 configure the f irst-stage g ain of input channels 0 through 3, respecti v ely . – Jumpers W4, W20, W30, and W42 configure the second-stage gain of inpu t channels 0 throug h 3, respecti vely . – Jumpers W5, W[...]

  • Page 20

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-4 www .natinst.com On Revision C or later modules, jumper W44 does not exist. SLO T0SEL* is alw ays b uf fered to the INTR* line. Jumper W38 Position 1 connects, after buffering, the SCXIb us MISO line to the SERDATOUT pin of the rear signal connector. In this setting, along with the [...]

  • Page 21

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-5 SCXI-1121 User Manual W38 in its factory default position (position 1). On all b ut one of the SCXI-1121s that are cabled to the data acquisition board, mo v e jumper W32 to position 3. It d oes not matter which of the SCXI-1121 modu les that are cabled to the data acq[...]

  • Page 22

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-6 www .natinst.com Analog Configuration The SCXI-1121 has 45 analog configuration jumpers. Before starting, notice that the jumper conf igurations for each input channel and each excitation channel are similar only the jumper numbers dif fer . Therefore, when you learn ho w to set up [...]

  • Page 23

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-7 SCXI-1121 User Manual Position AB-R1 connects the analog reference to the SCXIb us guard. Position A-R0R1 is the parking positi on and the factory setting. Position AB-R2 enables the Pseudodifferential Reference mode and connects the analog reference to the OUTREF pin [...]

  • Page 24

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-8 www .natinst.com Input Channel Jumpers Gain Jumpers Each input channel has two gain stages. The first gain stage provides gains of 1, 10, 50, and 100 and the second stage pro vides gains of 1, 2, 5, 10, and 20. Tables 2-3 and 2-4 show how to set up the gain for each channel. The boa[...]

  • Page 25

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-9 SCXI-1121 User Manual Filter Jumpers Two-stage filtering is also available on your SCXI-1121 module. The first stage is located in the isolated section of the input channel, whereas the second stage is located in the nonisolated section of the input channel. This permi[...]

  • Page 26

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-10 www .natinst.com Excitation Level Each excitation channel of your SCXI-1121 has two different current or voltage levels. You can set a given channel to one of the following level modes: • In the Current mode 0.150 or 0.450 mA • In the V oltage mode 3.333 or 10 V It is important[...]

  • Page 27

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-11 SCXI-1121 User Manual After selecting the excitation mode of operation desired—V oltage or Current—as described in the pre vious section, use T able 2-8 to set your SCXI-1121 for the lev el of operation. Y our SCXI-1121 is shipped with the V oltage mode set to 3.3[...]

  • Page 28

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-12 www .natinst.com Using the Internal Half-Bridge Completion Your SCXI-1121 includes half-bridge completion for half-bridge and quarter-bridge setups. The completion network consists of two 4.5 k Ω ± 0.05% ratio tolerance resistors with a temperature coefficient of 5 ppm/°C. Thes[...]

  • Page 29

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-13 SCXI-1121 User Manual 2 W27 and W28 3 W39 and W40 Table 2-9. Completio n Network Jumpers (Continued) Channel Jumpers Enable Comp le tion Disable Network (F actory Setting) A B W28 W27 1 2 3 • • • • • • • A B W28 W27 1 2 3 • • • • • • • A B [...]

  • Page 30

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-14 ww w .natinst.com Hardware Installation You can install the SCXI-1121 in any available SCXI chassis. After you have made any necessary changes and have verified and recorded the jumper settings on the form in Ap pendi x G, Technical Supp ort Resources , you are ready to install the[...]

  • Page 31

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-15 SCXI-1121 User Manual Signal Connections This section describes the input and output signal connecti ons to th e SCXI-1121 board via the SCXI-1121 front connector and rear signal connector, and includes specifications and connection instructions for the signals given [...]

  • Page 32

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-16 www .natinst.com When connecting or disconnecting signal lines to the SCXI terminal block scre w terminals, make sure the lines are po wered of f. Potential differences between the lines and the SCXI ground create a shock hazard while you connect the lines. Connect the signal wires[...]

  • Page 33

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-17 SCXI-1121 User Manual Figure 2-3. SCXI-1121 Front Connector Pin Assignment Pin Number Signal Name Column A B C Signal Name 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 CGND +5 V EGND2 EX1+ EGND3 EX3+ CH3+ EX2+ CH2+ EGND1 CH1+ [...]

  • Page 34

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-18 www .natinst.com Front Connector Signal Descriptions Pin Signal Name Description A2 CGND Chassis Ground—This pin is tied to the SCXI chassis. C2 DTEMP Direct T emperature Sensor—This pin connects the temperature sensor to the MCH4+ when the terminal block is configured for dire[...]

  • Page 35

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-19 SCXI-1121 User Manual The signals on the front connector are all analog except pins A6, C6, and C8, which are digital controls. These analog signals can be di vided into three groups—the analog input channels, the excitation channels, and the temperature sensor . A2[...]

  • Page 36

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-20 www .natinst.com Analog Input Channels The positive input channels are located in column A. Their corresp onding negative input channels are located in column C. Each input corresponds to a separate amplifier and is fully isolated from the other channels and from earth ground. The [...]

  • Page 37

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-21 SCXI-1121 User Manual Figure 2-6. Floating AC-Coupled Signal Connection Figure 2-7. AC-Coupled Signal Connection with High Common-Mode V oltage For A C-coupled signals, you should connect an external resistor from the positi ve input channel to the signal reference. T[...]

  • Page 38

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-22 www .natinst.com Warning Exceeding the input signal range and the common-mode input range results in distorted signals. Exceeding the maximum input voltage rating (250 V rms between positi ve and negati v e terminals and between any terminal and earth ground) can damage th e SCXI-1[...]

  • Page 39

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-23 SCXI-1121 User Manual 3. T urn off your SCXI chassis. 4. Slide the selected module out of the SCXI chassis. 5. Remov e the module co v er . 6. Place one jack scre w on the SCXI-1121 as indicated in Figure 2-8. 7. While holding the jack scre w in place, insert the lock[...]

  • Page 40

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-24 www .natinst.com SCXI-1320, SCXI-1328, and SCXI-1321 T erminal Blocks The second type of connector available to connect the transducers to the SCXI-1121 inputs is a terminal b lock with an onboard temperature sensor and screw terminals for easy connection. One terminal block, the S[...]

  • Page 41

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-25 SCXI-1121 User Manual SCXI-1321 Offset-Null and Shunt-Calibration T erminal Block The SCXI-1321 terminal block operates only with Rev ision C and later SCXI-1121 modules. In addition to the 18 scre w terminals, the SCXI-1321 has circuitry for of fset-null adjust of Wh[...]

  • Page 42

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-26 www .natinst.com The v alue of all the nulling resistors on your term inal block is 39 k Ω . Notice that these resistors are socketed for easy replacement. These sockets best f it a 1/4 W resistor lead size. T o determine your nulling range, use the following formula (refer to Fi[...]

  • Page 43

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-27 SCXI-1121 User Manual Assuming a strain-gauge range with a g auge factor of GF = 2 and a quarter-bridge conf iguration, this range corresponds to ±1,498 µ ε as giv e n by the strain formula for a quarter -bridge strain-gauge configuration: where Figure 2-9. Nulling[...]

  • Page 44

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-28 www .natinst.com SCXI-1121 S hunt Calib ration Shunt calibration circuits are independent from each other but are controlled together. In other words, when SCAL is set to 1 on the SCXI-1121, all the shunt switches close when SCAL is cleared to 0, all the switches open. At startup o[...]

  • Page 45

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-29 SCXI-1121 User Manual Figure 2-10. Shunt Cir cuit The shunting resistors R SCAL are sock eted so that you can replace them with a resistor of another v alue to achie v e the required changes. The R SCAL resistors on your terminal block have a 301 k Ω ±1% value. Ass[...]

  • Page 46

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-30 www .natinst.com T erminal Block T emperature Sensor To accommodate thermocouples with the SCXI-1121, the terminal block has an onboard temperature sensor for cold-junction compensation. You can connect this temperature sensor in two ways: • Y ou can connect the temperature senso[...]

  • Page 47

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-31 SCXI-1121 User Manual a = 1.288 x 10 –3 b = 2.356 x 10 –4 c = 9.556 x 10 –8 R T = resistance of the thermistor in Ω V TEMPOUT = output voltage of the temperature sensor where T (°F) and T (°C) are the temperature readings in degrees Fahrenheit and degrees Ce[...]

  • Page 48

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-32 www .natinst.com T ables 2-13, 2-14, and 2-15 show the jumper settings on the SCXI-132 0, SCXI-1328, and SCXI-1321 terminal blocks. Table 2-13. Jumper Settings on the SCXI-1320 T erminal Block Jum p e r Pos i t i on Description W1 MTS mode selected; factory setting; parking positio[...]

  • Page 49

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-33 SCXI-1121 User Manual T erminal Block Signal Connection Warnings The chassis GND terminals on your terminal block are for grounding high impedance sources such as a floating source (1 mA maximum). Do not use these terminals as safety earth grounds. If high voltages ( [...]

  • Page 50

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-34 www .natinst.com Figure 2-11. SCXI-1320 Parts Locator Diagram[...]

  • Page 51

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-35 SCXI-1121 User Manual Figure 2-12. SCXI-1328 Parts Locator Diagram[...]

  • Page 52

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-36 www .natinst.com Figure 2-13. SCXI-1321 Parts Locator Diagram T erminal Block Installation To connect the terminal block to the SCXI-1121 front conn ector, perform the following steps: 1. Connect the SCXI-1121 front connector to its mating connector on the terminal block. 2. Make s[...]

  • Page 53

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-37 SCXI-1121 User Manual Rear Signal Connector Note If you are using the SCXI-1121 with a National Instruments data acquisition board and cable assembly , you do not need to read the remainder of this chapter . If you are using the SCXI-1180 feedthrough p anel, the SCXI-[...]

  • Page 54

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-38 www .natinst.com Rear Signal Connector Signal Descriptions Pin Signal Name Description 1-2 AO G N D Analog Output Ground—These pins are connected to the analog reference when jumper W33 is in position AB-R0. 3-12 MCH0± through MCH4± Analog Output Channels 0 through 4—Connects[...]

  • Page 55

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-39 SCXI-1121 User Manual The signals on the rear signal connector can be classified as analog output signals, digital I/O signals, or timing I/O signals. Signal connection guidelines for each of these groups are giv en in the follo wing section. Analog Output Signal Conn[...]

  • Page 56

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-40 www .natinst.com Digital I/O Signal Connections Pins 24 through 27, 29, 33, 36, 37, and 43 constitute the digital I/O lines of the rear signal connector. They are divided into three categories—the digital input signals, the digital output signals, and the digital timing signals. [...]

  • Page 57

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-41 SCXI-1121 User Manual The digital timing signals are pins 36 and 43. • Pin 36 is used as a clock by the SCXI-1121 to increment the MUXCOUNTER after each con version b y the data acquisition board during scanning. This signal is referred to as SCANCLK. See Chapter 3,[...]

  • Page 58

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-42 ww w .natinst.com T iming Requirements and Communication Protocol T iming Signal The data acquisition timing signal is SCANCLK. SCANCLK is used to increment MUXCOUNTER on its rising edge. Figur e 2-15 sh o ws the timing requirements of the SCANCLK signal. These requirements will en[...]

  • Page 59

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-43 SCXI-1121 User Manual Figure 2-16. Slot-Select Timing Diagr am T o write the 16-bit slot-select number to Slot 0, follo w these steps: 1. Initial conditions: SERD A TIN = don't care D A QD*/A = don't care SLO T0SEL* = 1 SERCLK = 1 2. Clear SLO T0SEL* to 0. T[...]

  • Page 60

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-44 www .natinst.com Figure 2-17 sho ws the timing requirements on the SERCLK and SERD A TIN signals. Y ou must observe these timing requirements for all communications. T delay is a specification of the SCXI-1121. Figure 2-17. Serial Data Timing Diagram After the Slot-Select line to a[...]

  • Page 61

    Chapter 2 Configuration and Installation © National Instruments Corporation 2-45 SCXI-1121 User Manual 3. Pull SLO T0SEL* lo w to deassert the SS* line and establish conditions for writing a ne w slot-select number to the Slot 0 Slot-Select Re gister . 4. If you are not selecting another slot, you shou ld write zero to the Slot 0 Slot-Select Regis[...]

  • Page 62

    Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-46 www .natinst.com Figure 2-19 illustrates a read of the SCXI-1121 Module ID Register . Figure 2-19. SCXI-1121 Module ID Register Timing Diagram For further details on programming these signals, refer to Chapter 5, Programming . SLOT0SEL* SS* SERCLK 00 00 00 0000 000 0000 000 0000 00[...]

  • Page 63

    © National Instruments Corporation 3-1 SCXI-1121 User Manual 3 Theor y of Operation This chapter contains a functional overview of the SCXI-112 1 module and explains the operation of each functional unit making up the SCXI-1121. Functional Over view The block diagram in Figure 3-1 illustrates the key functio nal components of the SCXI-1121. Figure[...]

  • Page 64

    Chapter 3 Theory of Operation SCXI-1121 User Manual 3-2 www .natinst.com The major components of the SCXI-1121 are as follo w s: • SCXIbus connector • Digital interface • Digital control circuitry • T iming and analog circuitry The SCXI-1121 consists of four isolated amplifier channels with gains of 1, 2, 5, 10, 20, 50, 100, 200, 500, 1,000[...]

  • Page 65

    Chapter 3 Theory of Operation © National Instruments Corporation 3-3 SCXI-1121 User Manual SCXIbus Connector Figure 3-2 shows the pin assignments for the SCXIbus connector. Figure 3-2. SCXIbus Connector Pin Assignment A1 B1 A2 B2 A3 B3 A4 B4 A5 B5 A6 B6 A7 B7 A8 B8 A9 B9 A10 B10 A1 1 B1 1 A12 B12 A13 B13 A14 B14 A15 B15 A16 B16 A17 B17 A18 B18 A19[...]

  • Page 66

    Chapter 3 Theory of Operation SCXI-1121 User Manual 3-4 www .natinst.com SCXIbus Connector Signal Descriptions Pin Signal Name Description A1, B1, C1, D1, A2, D2,A3, B3, C3, D3, A4, D4, A5, B5, C5, D5, A6, D6 GU ARD Guard—Shields a nd guards the analog b us lines from noise. B2 AB0+ Analog Bus 0+ —Positi ve analog b us 0 line. Used to multiplex[...]

  • Page 67

    Chapter 3 Theory of Operation © National Instruments Corporation 3-5 SCXI-1121 User Manual MOSI, MISO, SPICLK, and SS* form a synchronous communication link that conforms with SPI using an idle-high clock and second-edge data latching. D*/A, INTR*, and RESET* are additional control signals. When the module is being used in an SCXI-1000 or SCXI-100[...]

  • Page 68

    Chapter 3 Theory of Operation SCXI-1121 User Manual 3-6 www .natinst.com chassis is being used), and then releasing INTR* high. At this point, SS* of the desired slot is asserted lo w and the data acquisition board can communicate with the module in that slot according to the SPI protoc ol. Digital Interface Figure 3-3 shows a diagram of the SCXI-1[...]

  • Page 69

    Chapter 3 Theory of Operation © National Instruments Corporation 3-7 SCXI-1121 User Manual Digital Control Circuitr y Figure 3 -4 diagrams the SCXI-1121 digital control. Figure 3-4. SCXI-1121 Digital Control The digital control section consists of the Conf iguration Register and the Module ID Register . The Configuration Re gister is a two-b yte, [...]

  • Page 70

    Chapter 3 Theory of Operation SCXI-1121 User Manual 3-8 www .natinst.com 3. The serial data is a v ailable on MOSI and SPICLK clocks it into the register . 4. SS* goes high and D*/A goes high, indicating an end of communication. This action latches the Configuration Register bits. When the SCXIb us is reset, all bits in the Conf iguration Register [...]

  • Page 71

    Chapter 3 Theory of Operation © National Instruments Corporation 3-9 SCXI-1121 User Manual Figure 3-5. Analog Input Block Diagram + – + – + – + – Input Channel 1 + – + – + – + – Input Channel 2 Input Channel 3 MTEMP DTEMP Input Channel 0 LPF I + – T o Output Stage LPF LPF + – T o Output Stage LPF + – T o Output Stage LPF + ?[...]

  • Page 72

    Chapter 3 Theory of Operation SCXI-1121 User Manual 3-10 www .natinst.com The analog input consists of four isolated single-ended nonin verting amplifiers. In addition, lowpass filtering is a v ailable at the inputs. Y ou can jumper select one of two bandwidths, 10 kHz or 4 Hz. The amplif ier gain is divided into two stages, a f irst stage providin[...]

  • Page 73

    Chapter 3 Theo r y of Operation © National Instruments Corporation 3-11 SCXI-1121 User Manual After isolation, further f iltering is a v ailable to increase the noise immunity of the ampli f ier channel. It is important to note that t he o v erall ampli f ier bandwidth is determined b y both f iltering stages, so to achi e v e the required bandwid[...]

  • Page 74

    Chapter 3 Theory of Operation SCXI-1121 User Manual 3-12 www .natinst.com • Y ou also need a 120 Ω 1/4 W precision resistor with tempco less than or equal to 5 ppm, or an ammeter with the following specif ications: – Accuracy: ±0.004% standard ±0.016% suff icient – Range: 0.5 mA – Resolution: 6 1/2 digits • If you use the resistor to [...]

  • Page 75

    Chapter 3 Theory of Operation © National Instruments Corporation 3-13 SCXI-1121 User Manual 8. Adjust the input potentiometer of the channel of interest un til th e output is 0 ± 6 mV . 9. Go to the next channel. T o av oid erroneous results when n ulling the amplifier , follow these steps in the order indicated. Excitation Adjust When calibratin[...]

  • Page 76

    Chapter 3 Theory of Operation SCXI-1121 User Manual 3-14 www .natinst.com This procedure calibrates the 10 V and 450 µA levels at the same time b ut the accuracy achie v ed is limited to ±0.2%. T o achie ve better accuracie s at these le vels, follo w the procedure indicated abov e b ut set the excitation le v els to 10 V and to 450 µA instead o[...]

  • Page 77

    Chapter 3 Theory of Operation © National Instruments Corporation 3-15 SCXI-1121 User Manual Analog Output Circuitr y Figure 3-6 shows the SCXI-1121 analog output circuitry. Figure 3-6. Analog Output Cir cuitry The SCXI-1121 output circu itry consists of a buf fered-outp ut multiplexer and channel-select hardware. The channel-select hardw are consi[...]

  • Page 78

    Chapter 3 Theory of Operation SCXI-1121 User Manual 3-16 www .natinst.com in the Conf iguration Re gister when SCANCON is high (inacti v e) and will count upwards on each rising clock edge when SCANCON is lo w (acti v e). In the P arallel-Output Mode, the MUXCOUNTER is disabled and its output indicates binary 00 hence, amplif ier channel 0 is selec[...]

  • Page 79

    Chapter 3 Theory of Operation © National Instruments Corporation 3-17 SCXI-1121 User Manual Scanning Modes There are four basic types of scanning modes poss ible with the SCXI-1121—single-module parallel scanning, single-mod ule multiplexed scanning, multiple-module multiplexed scanning, and multiple-chassis scanning (possible only with the SCXI[...]

  • Page 80

    Chapter 3 Theory of Operation SCXI-1121 User Manual 3-18 www .natinst.com entry. The list in Slot 0 will determine which module is being accessed and for how many samples. It is impo rtan t that you make sure that the lists on the data acquisition board and Slot 0 are compatible so that the samples are acquired as intended. See your SCXI chassis ma[...]

  • Page 81

    Chapter 3 Theory of Operation © National Instruments Corporation 3-19 SCXI-1121 User Manual Figure 3-9. Single-Module Multiplexed Scanning (Indirect) Multiple-Module Multiplexed Scanning In this mode, all the modules tie into Analog Bus 0, and SCANCON enables the output of their amplifiers. The module that is directly cabled to the data acquisitio[...]

  • Page 82

    Chapter 3 Theory of Operation SCXI-1121 User Manual 3-20 www .natinst.com Multiple-Chassis Scanning In this mode, you attach each SCXI-1001 chassis to a daisy chain of cable assemblies and multichassis adapter boards, as illustrated in Figure 3-11. You program each chassis separately, and each chassis occupies a dedicated channel of the data acquis[...]

  • Page 83

    © National Instruments Corporation 4-1 SCXI-1121 User Manual 4 Register Descriptions This chapter describes in detail the SCXI-1121 Module ID Register, the Configuration Register, the Slot 0 registers, and multiplexer addressing. Note If you plan to use a programming software package such as NI-D A Q, LabWindo ws, or LabVIEW with your SCXI-1121 bo[...]

  • Page 84

    Chapter 4 Register Descriptions SCXI-1121 User Manual 4-2 www .natinst.com Module ID Register The Module ID Register contains the 4-b yte module ID code for the SCXI-1121. This code number will be read as the f irst four bytes on the MISO line whenever the module is accessed. The bytes will appear least significant b yte f irst. W ithin each byte, [...]

  • Page 85

    Chapter 4 Register Descriptions © National Instruments Corporation 4-3 SCXI-1121 User Manual Configuration Register The Configuration Register contains 16 bits that control the functions of the SCXI-1121. When SS* is asserted (low) and D*/A indicates data (low), the register will shift in th e data present on the MOSI line, bit 15 first, and then [...]

  • Page 86

    Chapter 4 Register Descriptions SCXI-1121 User Manual 4-4 www .natinst.com 9-8 CHAN<1..0> Channel Select—These bits determine the channel number (zero to three) that is loaded into the MUXCOUNTER to determine the analog channel to be read during a single read, or the starting channel on the module for a scanned data acquisition. CHAN1 is th[...]

  • Page 87

    Chapter 4 Register Descriptions © National Instruments Corporation 4-5 SCXI-1121 User Manual 0 FOUTEN* Forced Output Enable—This bit determines whet her the module will drive th e MCH0± pins on the rear signal connector with either the selected channel output or t he MTEMP signal, depending on the state of RTEMP. If FOUTEN* is cleared to zero, [...]

  • Page 88

    Chapter 4 Register Descriptions SCXI-1121 User Manual 4-6 www .natinst.com Slot-Select Register The Slot-Select Register contains 16 bits that determine which module in which chassis will be enabled for communication when the SLO T0SEL* line is set to one. An SCXI-1000 chassis will select the appropriate module in its chassis, re gardless of the ch[...]

  • Page 89

    Chapter 4 Register Descriptions © National Instruments Corporation 4-7 SCXI-1121 User Manual Hardscan Control Register (HSCR) The HSCR contains eight bits that control the setup and operation of the hardscan timing circuitry of Slot 0. T o write to the HSCR, follow the procedure gi ven in the Register Writes section of Chapter 5, Programming , usi[...]

  • Page 90

    Chapter 4 Register Descriptions SCXI-1121 User Manual 4-8 www .natinst.com 1 SCANCONEN Scan Control Enable—When set, this bit enables the SCANCON lines. When clear, all SC ANCON lines are disabled (high). 0 CLKEN Clock Enable—When set , this bit enables TRIG0 as a clock for the hardscan circuitry. When clear, T RIG0 is disabled.[...]

  • Page 91

    Chapter 4 Register Descriptions © National Instruments Corporation 4-9 SCXI-1121 User Manual FIFO Register The FIFO Register is used to add entries to the Slot 0 FIFO. The FIFO contains the Slot 0 scan list. Each entry contains a slot number to be accessed, and a count number to determine the number of samples to be taken from that slot. T o write[...]

  • Page 92

    © National Instruments Corporation 5-1 SCXI-1121 User Manual 5 Programming This chapter contains a functional programming description of the SCXI-1121 and Slot 0. Note If you plan to use a programming software package such as NI-D A Q, LabWindo ws, or LabVIEW with your SCXI-1121 board, you do not need to read this chapter . Programming Considerati[...]

  • Page 93

    Chapter 5 Programming SCXI-1121 User Manual 5-2 ww w .natinst.com Register Writes This section describes how to write to the Configuration Register, HSCR, and FIFO Register including the procedure for writing to the Slot-Select Register to select the appropriate slot. For timing specifics, refer to the Timing Requirements and Communication Protocol[...]

  • Page 94

    Chapter 5 Programming © National Instruments Corporation 5-3 SCXI-1121 User Manual 3. For each bit, starting with the MSB fi rst (bit 15): a. SERD A TIN = bit to be sent. These bits are the data that is being written to the Slot-Select Re gister . b . Clear SERCLK to 0. c. Set SERCLK to 1. This rising edge clocks the data. (If you are using an MIO[...]

  • Page 95

    Chapter 5 Programming SCXI-1121 User Manual 5-4 www .natinst.com to MCH0 through MCH3 on the rear signal connector. The module is disconnected from Analog Bus 0 and disabled from scanning. Single-Channel Measurements This section describes how to program the SCXI-1121, either alone or in conjunction with other modules, to make single-channel, or no[...]

  • Page 96

    Chapter 5 Programming © National Instruments Corporation 5-5 SCXI-1121 User Manual T o measure one of the four diff erential input channels to the SCXI-1121, perform the follo wing steps: 1. Write the binary pattern 000XXXCC XX000000 to the SCXI-1121 Configuration Re gister . 2. Measure the vo ltage with the data acquisition board. T o shunt calib[...]

  • Page 97

    Chapter 5 Programming SCXI-1121 User Manual 5-6 www .natinst.com Measurements from the SCXI-1121 via Another Module To perform measurements via another module, you must cable the other module rear signal connector to a data acqu isition board. The other mo dule must also be able to transfer Analog Bus 0 to the data acquisition board. See Chapter 2,[...]

  • Page 98

    Chapter 5 Programming © National Instruments Corporation 5-7 SCXI-1121 User Manual Scanning Measurements Programming for scanned data acquisition involves programmin g your data acquisition board, mod ules, and Slot 0. In general, the steps to b e taken are as follows: 1. Perform all data acquisition board programming to the point of enabling the [...]

  • Page 99

    Chapter 5 Programming SCXI-1121 User Manual 5-8 www .natinst.com • AT-MIO-16X User Manual – Continuous Channel Scanning Data Acquisition – Interval Channel Scanning Data Acquisition • AT-MIO-64F-5 User Manual – Continuous Channel Scanning Data Acquisition – Interval Channel Scanning Data Acquisition • Lab-LC User Manual – Programmin[...]

  • Page 100

    Chapter 5 Programming © National Instruments Corporation 5-9 SCXI-1121 User Manual Follo w the i nstructions in these sections th rough the part la beled as follows: • Clear the A/D Circuitry and Reset the Mux Co unter in the MIO board user manual (except for the A T -MIO-16X and the A T -MIO-64F-5). Do not continue to the part called Enable the[...]

  • Page 101

    Chapter 5 Programming SCXI-1121 User Manual 5-10 www .natinst.com T o program the MIO board to take N samples per data acquisition board scan list entry , perform the following additional programming steps at the end of the Enable the Sc anning Data Acquisition Operat ion section in the appropriate data acquisition board user manual: 1. Write FF01 [...]

  • Page 102

    Chapter 5 Programming © National Instruments Corporation 5-11 SCXI-1121 User Manual Single-Module Multiplexed Scanning (Direct) To perform simple channel scanning, you must cable the SCXI-1121 to a data acquisition board. See Chapter 2, Configuration and Installatio n , for more information. T o program the module for scann ed channel measurements[...]

  • Page 103

    Chapter 5 Programming SCXI-1121 User Manual 5-12 www .natinst.com 2. Program the other module not to dri v e Analog Bus 0, but to send Analog Bus 0 to the data acquisition board. Also program the other module to send a SCANCLK*-compatible signal to TRIG0. 3. Write the binary pattern 01 S c XXXCC XX001111 to the SCXI-1121 Conf iguration Register , w[...]

  • Page 104

    Chapter 5 Programming © National Instruments Corporation 5-13 SCXI-1121 User Manual channel. See the Counter 1 and SCANDIV subsection of the 1. Data Acquisition Board Setup Programming section earlier in this chapter. You can use the MIO-16 boards in conjunction with the SCXI-1350 multichassis adapter for multichassis scanning. For each chassis, p[...]

  • Page 105

    Chapter 5 Programming SCXI-1121 User Manual 5-14 www .natinst.com 5. Write binary 101S 1100 to the HSCR. 6. Write binary 101S 1110 to the HSCR. 7. Write binary 101S 1111 to the HSCR. In the preceding steps, S = 0 if you want the scanning to repeat when the end of the list is reached. S = 1 if you want the circuitry to shut do wn after a single scan[...]

  • Page 106

    Chapter 5 Programming © National Instruments Corporation 5-15 SCXI-1121 User Manual • Lab-NB User Manual – Program the sample-interv al counter (Counter A0) – Service the data acquisition operation. Scanning Examples The following examples are intended to aid your understandin g of module and Slot 0 program ming. It will be helpful to refer [...]

  • Page 107

    Chapter 5 Programming SCXI-1121 User Manual 5-16 www .natinst.com 2. Follo wing th e procedure giv en in the Register Writes section, write 00000000 00000000 to the Conf iguration Re gister of the SCXI-1121 in Slot 2. This step resets the module, including the clearing of the AB0EN bit (bit 0). Notice that a complete reset of this module is not nec[...]

  • Page 108

    Chapter 5 Programming © National Instruments Corporation 5-17 SCXI-1121 User Manual Assuming that the modules are cabled and programmed correctly , the Slot 0 scan lists should be as follo ws: Other solutions are possible. In the section, 3. Programming the Slot 0 Hardscan Circuitry , earlier in this chapter , step 3 consists of the following step[...]

  • Page 109

    © National Instruments Corporation A-1 SCXI-1121 User Manual A Specifications This appendix lists the specif ications for the SCXI-1121. These are typical at 25 °C unless otherwise stated. The operating temperature range is 0 to 50 °C. Analog Input Gain (jumper-selectable) ............... ......... 1, 2, 5, 10, 20, 50, 100, 200, 500, 1,000, 2,00[...]

  • Page 110

    Appendix A Specifications SCXI-1121 User Manual A-2 www .natinst.com Filtering (jumper-selectable) ..................4 Hz (– 10 dB) or 10 kHz (–3 dB), 3-pole RC Noise (400 kHz bandwidth) 1 Input (gain = 1,000) 4 Hz filter ............... ............ ......100 nV rms 10 kHz filter ............................ .4 µV rms Output (gain = 1) 4 Hz .[...]

  • Page 111

    Appendix A Specifications © National Instruments Corporation A-3 SCXI-1121 User Manual R TD Mode Excitation current ......... ... .............. ......... 0.15 mA ±0.04%, 0.45 mA ±0.2% Maximum load resistance ...................... 10 k Ω Drift .......... ........... ............ .. ............ .. ....... 40 ppm/ °C Lead resistance effect ..[...]

  • Page 112

    Appendix A Specifications SCXI-1121 User Manual A-4 www .natinst.com Note Y ou can find the temperature T (°C) as follo ws: T = T K – 273.15 where T K is the temperature in kelvin a = 1.288 x 10 –3 b = 2.356 x 10 –4 c = 9.556 x 10 –8 R T = resistance of the thermistor in Ω V TEMPOUT = output voltage of the temperature sensor Physical Dim[...]

  • Page 113

    © National Instruments Corporation B-1 SCXI-1121 User Manual B Rear Signal Connector This appendix describes the pinout and signal names for the SCXI-1121 50-pin rear signal connector , including a description of each connection. Figure B-1 shows the pin assignments for the SCXI-1121 rear signal connector . Figure B-1. SCXI-1121 Rear Signal Connec[...]

  • Page 114

    Appendix B Rear Signal Connector SCXI-1121 User Manual B-2 www .natinst.com Rear Signal Connector Signal Descriptions See the Timing Requirements and Communication Protocol section in Chapter 2, C onfiguration and Installation , for more detailed i nformation on timing. Detailed signal specif ications are also included in Chapter 2. Pin Signal Name[...]

  • Page 115

    © National Instruments Corporation C-1 SCXI-1121 User Manual C SCXIbus Connector This appendix describes the pinout and signal names for the SCXI-1121 96-pin SCXIb us connector , including a description of each connection.[...]

  • Page 116

    Appendix C SCXIbus Connector SCXI-1121 User Manual C-2 www .natinst.com Figure C -1 shows the pin assignments for the SCXI-1121 SCXIbu s connector . Figure C-1. SCXIbus Connector Pin Assignment A1 B1 A2 B2 A3 B3 A4 B4 A5 B5 A6 B6 A7 B7 A8 B8 A9 B9 A10 B10 A1 1 B1 1 A12 B12 A13 B13 A14 B14 A15 B15 A16 B16 A17 B17 A18 B18 A19 B19 A20 B20 A21 B21 A22 [...]

  • Page 117

    Appendix C SCXIbus Connector © National Instruments Corporation C-3 SCXI-1121 User Manual SCXIbus Connector Signal Descriptions Pin Signal Name Description A1, B1, C1, D1, A2, D2,A3, B3, C3, D3, A4, D4, A5, B5, C5, D5, A6, D6 GU ARD Guard—Shields and guards the analog bus lines from noise. B2 AB0+ Analog Bus 0+ —Positi v e analog b us 0 line. [...]

  • Page 118

    Appendix C SCXIbus Connector SCXI-1121 User Manual C-4 www .natinst.com Further infor mation is giv en in Chapter 3, Theory of Operation . A24 TRIG0 TRIG0—General-purpose trigger line used by the SCXI-1121 to send SCANCLK to other modules or recei ve SCANCLK fr om other modules. Open collector . I/O. B24 SS* Slot Select—When lo w , enables modu[...]

  • Page 119

    © National Instruments Corporation D-1 SCXI-1121 User Manual D SCXI-1121 Front Connector This appendix describes the pinout and signal names for the SCXI-1121 front connector , including a description of each connection.[...]

  • Page 120

    Appendix D SCXI-1121 Front Connector SCXI-1121 User Manual D-2 www .natinst.com Figure D -1 shows the pin assignments for the SCXI-1121 front connector . Figure D-1. SCXI-1121 Front Connector Pin Assignment Pin Number Signal Name Column A B C Signal Name 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 CGND +5 [...]

  • Page 121

    Appendix D SCXI-1121 Front Connector © National Instruments Corporation D-3 SCXI-1121 User Manual Front Connector Signal Descriptions Pin Signal Name Description A2 CGND Chassis Ground—This pin is tied to the SCXI chassis. C2 DTEMP Direct T emperature Sensor—This pin connects the temperature sensor to the MCH4+ when the terminal block is confi[...]

  • Page 122

    Appendix D SCXI-1121 Front Connector SCXI-1121 User Manual D-4 www .natinst.com Further infor mation is giv en in Chapter 2, Configuration and Installa tion . C18 EX2– Negati ve Excitation Output 2—This pin is connected to the excitation channel 2 ne gati v e output. A20 CH2+ Positi v e Input Channel 2—This pin is connected to the input chann[...]

  • Page 123

    © National Instruments Corporation E-1 SCXI-1121 User Manual E SCXI-1121 Cabling This appendix describes ho w to use and install the hardw are accessories for the SCXI-1121: • SCXI-1340 cable assembly • SCXI-1341 Lab-NB, Lab-PC, and Lab-PC+ cable assembly • SCXI-1344 Lab-LC cable assembly • SCXI-1342 PC-LPM-16 cable assembly • SCXI-1180 [...]

  • Page 124

    Appendix E SCXI-1121 Cabling SCXI-1121 User Manual E-2 www .natinst.com Y ou can use a standard 50-pin ribbon cable instead of the SCXI-1340 cable assembly . The SCXI-1340 has the following adv antages ov er the rib bon cable: • The SCXI-1340 has strain relief so that you cannot accidentally disconnect the cable. • The SCXI-1340 includes a moun[...]

  • Page 125

    Appendix E SCXI-1121 Cabling © National Instruments Corporation E-3 SCXI-1121 User Manual No other pins are connected on the SCXI-1121. SCXI-1340 Installation Follo w th ese steps to in stall th e SCXI-1340: 1. Make sure that the computer and the SCXI chassis are turned of f. 2. Install the SCXI module in the chassis. 3. Plug the mounting bracket [...]

  • Page 126

    Appendix E SCXI-1121 Cabling SCXI-1121 User Manual E-4 www .natinst.com Figure E-1. SCXI-1340 Installation SCXI-1341 Lab-NB, Lab-PC, or Lab-PC+ and SCXI-1344 Lab-LC Cable Assembly The SCXI-1341 Lab-NB, Lab-PC, or Lab-PC+ cable assembly connects a Lab-NB, Lab-PC, or Lab-PC+ board to an SCXI-1121 module. The SCXI-1344 Lab-LC cable assembly connects a[...]

  • Page 127

    Appendix E SCXI-1121 Cabling © National Instruments Corporation E-5 SCXI-1121 User Manual jumper W 1. T able E-2 lists the SCXI-1341 and SCXI-1344 pin translations. Note If you are using the Lab-PC+, configure the board for single-ended inputs. Table E-2. SCXI-1341 and SCXI-1344 Pin T ranslations Lab Board Pin Lab Board Signal SCXI-1121 Pin SCXI-1[...]

  • Page 128

    Appendix E SCXI-1121 Cabling SCXI-1121 User Manual E-6 www .natinst.com All other pins of the Lab board pinout are not sent to the SCXI-1121 rear signal connector . SCXI-1341 and SCXI-1344 Installation Follo w th ese steps to in stall th e SCXI-1341 or SCXI-1344: 1. Make sure that the computer and the SCXI chassis are turned of f. 2. Install the SC[...]

  • Page 129

    Appendix E SCXI-1121 Cabling © National Instruments Corporation E-7 SCXI-1121 User Manual Table E-3. SCXI-1342 Pin T ranslations PC-LPM-16 Pin PC-LPM-16 Signal Rear Signal Connector Pin SCXI-1121 Use 1-2 AIGND 1-2 AO G N D 3 AC H 0 3 MCH0+ 4 AC H 8 4 MCH0– 5 AC H 1 5 MCH1+ 6 AC H 9 6 MCH1 - 7 AC H 2 7 MCH2+ 8 AC H 1 0 8 MCH2– 9 AC H 3 9 MCH3+ [...]

  • Page 130

    Appendix E SCXI-1121 Cabling SCXI-1121 User Manual E-8 www .natinst.com All other pins of the PC-LPM-16 pinout are not sent to the SCXI-1121 rear signal connector . SCXI-1342 Installation Follo w th ese steps to in stall th e SCXI-1342: 1. Make sure that the computer and the SCXI chassis are turned of f. 2. Install the SCXI module to which the SCXI[...]

  • Page 131

    Appendix E SCXI-1121 Cabling © National Instruments Corporation E-9 SCXI-1121 User Manual SCXI-1180 Installation Install the SCXI-1180 to the right of a slot that has an SCXI-1340, SCXI-1341, SCXI-1342, or SCXI-1344 cable assembly or an SCXI-1351 slot extender in its rear connector space. Follo w th ese steps to in stall th e SCXI-1180: 1. Make su[...]

  • Page 132

    Appendix E SCXI-1121 Cabling SCXI-1121 User Manual E-10 www .natinst.com Figure E-3. SCXI-1180 Front Panel Installation SCXI-1302 50-Pin T erminal Block The SCXI-1302 terminal block has screw terminal connections for the 50-pin connector on the SCXI-1 180 feedthrough panel. SCXI-1302 Wiring Procedure T o wire the SCXI-1302 terminal block, you must [...]

  • Page 133

    Appendix E SCXI-1121 Cabling © National Instruments Corporation E-11 SCXI-1121 User Manual 6. Snap the cov er back in place. 7. Reinsert the rear grounding screw . The terminal block is no w ready to be connected to the front panel connector . Figure E-4. Cover Removal SCXI-1302 Installation Follo w th ese steps to in stall th e SCXI-1302: 1. Inst[...]

  • Page 134

    Appendix E SCXI-1121 Cabling SCXI-1121 User Manual E-12 www .natinst.com SCXI-1351 One-Slot Cable Extender The SCXI-1351 cable extender is a miniature SCXI-1340 cable assembly . Instead of connecting to an MIO board 1 m a way , the SCXI-1351 female rear connector connects to the male break out connector of a module that must be in the rear connecto[...]

  • Page 135

    Appendix E SCXI-1121 Cabling © National Instruments Corporation E-13 SCXI-1121 User Manual The adapter board has a male rear connector , a female front connector , and a male chassis extender connector . Y ou can attach the rear connector to a ribbon cable from the MIO board or a preceding chassis. Y ou connect the front connector with the module [...]

  • Page 136

    Appendix E SCXI-1121 Cabling SCXI-1121 User Manual E-14 www .natinst.com SCXI-1343 Rear Screw T erminal Adapter Y ou use the SCXI-1343 universal adapter to adapt custom wiring to the SCXI-1121. The SCXI-1343 has screw terminals for the analog output connections and so lder pads for the rest of th e signals. A strain-relief clamp is on the outside o[...]

  • Page 137

    Appendix E SCXI-1121 Cabling © National Instruments Corporation E-15 SCXI-1121 User Manual 12 MCH4– Scre w terminal 13 No Connect Scre w terminal 14 No Connect Scre w terminal 15 No Connect Scre w terminal 16 No Connect Scre w terminal 17 No Connect Scre w terminal 18 No Connect Scre w terminal 19 OUTREF Scre w terminal 20 No Connect Solder pad [...]

  • Page 138

    Appendix E SCXI-1121 Cabling SCXI-1121 User Manual E-16 www .natinst.com 39 No Connect Solder pad 40 No Connect Solder pad 41 No Connect Solder pad 42 No Connect Solder pad 43 RSVD Solder pad 44 No Connect Solder pad 45 No Connect Solder pad 46 No Connect Solder pad 47 No Connect Solder pad 48 No Connect Solder pad 49 No Connect Solder pad 50 No Co[...]

  • Page 139

    © National Instruments Corporation F-1 SCXI-1121 User Manual F Revision A and B Photo and Parts Locator Diagrams This appendix contains a pho tograph of the Revision A and B SCXI-1121 signal conditioning module and the gen eral and detailed parts locator diagrams. Figure F-1 shows the SCXI-1121 module. Figur e s F-2 and F -3 sho w the general and [...]

  • Page 140

    Appendix F Revision A and B Photo and Parts Locator Diagrams SCXI-1121 User Manual F-2 www .natinst.com Figure F-2. Revision A and B SCXI-1121 General Parts Locator Diagram[...]

  • Page 141

    Appendix F Revision A and B Photo and Parts Locator Diagrams © National Instruments Corporation F-3 SCXI-1121 User Manual Figure F-3. Revision A and B SCXI-1121 Detailed Parts Locator Diagram[...]

  • Page 142

    © National Instruments Corporation G-1 SCXI-1121 User Manual G T echnical Support Resources This appendix describes the comprehensiv e resources a v ailable to you in the T echnical Sup port section of the National Instruments W eb site and provides technical support telephone numbers for you to use if you hav e trouble connecting to our W eb site[...]

  • Page 143

    Appendix G T echnical Support Resources SCXI-1121 User Manual G-2 www .natinst.com Software-Related Resources • Instrument Driver Network —A library with hundreds of instrument dri v ers for control of standalone instruments via GPIB, VXI, or serial interfaces. Y ou also can submit a request for a particular instrument dri ver if it does not al[...]

  • Page 144

    © National Instruments Corporation Glossary-1 SCXI-1121 User Manual Glossar y Pref ix Meaning V alue p- pico- 10 –1 2 n- nano- 10 –9 µ- micro- 10 –6 m- milli - 10 –3 k- kilo- 10 3 M- mega- 10 6 Numbers/Symbols ° degrees Ω ohms ε strain +5 V (signal) +5 VDC source signal A A amperes AB0+ positi ve analog b us 0 line signal AB0– negat[...]

  • Page 145

    Glossary SCXI-1121 User Manual Glossary-2 www .natinst.com A OGND analog output ground signal Arms amperes, root mean square A WG American W ire Gauge B BW bandwidth C C Celsius CH#+ positi ve input channe l number signal CH#– negati ve input channel number signal CHAN channel select bit CHS chassis bit CHSGND chassis ground signal CJR cold-junct[...]

  • Page 146

    Glossary © National Instruments Corporation Glossary-3 SCXI-1121 User Manual DIG GND digital ground signal DIN Deutsche Industrie Norme DMM digital multimeter DTEMP direct temperature sensor DTS direct temperature sensor E EGND# excitation ground number signal EX#+ positi v e excitation output number signal EX#– negati ve excitation output numbe[...]

  • Page 147

    Glossary SCXI-1121 User Manual Glossary-4 www .natinst.com HSRS* hardscan reset bit Hz hertz I I I input current leakage in. inches INTR* interrupt signal I/O input/output K K kelvin L LO AD* loa d bi t LSB least significant bit M m meters M megab ytes of memory MCH#+ positi v e analog output channel number signal MCH#– negati ve analog output ch[...]

  • Page 148

    Glossary © National Instruments Corporation Glossary-5 SCXI-1121 User Manual MTEMP multiple xed temperature sensor MTS multiplex ed temperature sensor N NRSE nonreferenced single-ended (input) O ONCE once bit OUTREF output reference signal P ppm parts per million R RAM random-access memory RD read bit RESET* reset signal rms root mean square RSE r[...]

  • Page 149

    Glossary SCXI-1121 User Manual Glossary-6 www .natinst.com S SCAL (bit) shunt cal ibrate bit SCAL (signal) shunt calibration signal SCANCLK scan clock signal SCANCLKEN scan clock enable bit SCANCON scanning control signal SCANCONEN scan control enable bit SCXI Signal Conditioning eXtensions for Instru mentation (bus) SDK software de v eloper’ s k[...]

  • Page 150

    Glossary © National Instruments Corporation Glossary-7 SCXI-1121 User Manual U UL Underwriters Laboratory V V volts V+ positi ve analog supply signal V– negati ve analog supply signal VDC v o lts direct current V IH volts input high V IL volts input lo w V OH volts output high V OL v olts output lo w V rms v olts, root mean square W Ww a t t s[...]

  • Page 151

    © National Instruments Corporation Index-1 SCXI-1121 User Manual Index Numbers +5 V signal front connector (table), 2-18, D-3 SCXIbus connector (table), 3-4 A AB0+ signal (table), 3-4, C-3 AB0- signal (table), 3-4, C-3 AB0EN bit, 4-4 AC-coupled signal connections external resistor required, 2-21 floating (figure), 2-21 referenced to chassis ground[...]

  • Page 152

    Index SCXI-1121 User Manual Index-2 www .natinst.com C cable assemblies. See SCXI-1121 cabling. cables, custom, 1-5 calibration, 3-11 to 3-14 equipment requirements, 3-11 to 3-12 excitation adjust, 3-13 to 3-14 offset null adjust, 3-11 potentiometer reference designators (table), 3-14 CGND signal (table), 2-18, D-3 CH0+ signal (table), 2-19, D-4 CH[...]

  • Page 153

    Index © National Instruments Corporation Index-3 SCXI-1121 User Manual Counter 1, scanning measurements, 5-9 to 5-10 current and voltage excitation jumpers, 2-9 to 2-10 custom cables, 1-5 D D*/A signal description (table), 3-4, C-3 SCXIbus equivalents for rear signal connector (table), 3-5 SCXIbus to SCXI-1 121 rear signal connector to DAQ board p[...]

  • Page 154

    Index SCXI-1121 User Manual Index-4 www .natinst.com F FIFO Reg ister description, 4-9 register writes, 5-2 to 5-4 filter jumpers allocation (table), 2-9 description, 2-9 fixed jumpers, 2-2 floating signal connections AC-coupled (figure), 2-21 referenced to chassis ground (figure), 2-20 FOUTEN* bit, 4-5 front connector, 2-16 to 2-36 analog input ch[...]

  • Page 155

    Index © National Instruments Corporation Index-5 SCXI-1121 User Manual SCXI-1341 Lab-NB, Lab-PC, or Lab-PC+ cable assembly, E-6 SCXI-1342 PC-LPM-16 cable assembly, E-8 SCXI-1343 rear screw terminal adapter, E-14 SCXI-1344 Lab-PC+ cable assembly, E-6 SCXI-1350 multichassis adapter, E-13 SCXI-1351 one-slot cable extender, E-12 terminal blocks, 2-36 [...]

  • Page 156

    Index SCXI-1121 User Manual Index-6 www .natinst.com SCXIbus to SCXI-1 121 rear signal connector to DAQ board pin equivalences (table), 2-41 MTEMP signal (table), 2-18, D-3 MTS mode, terminal blocks, 2-31 to 2-32 multiple-chassis scanning programming, 5-12 to 5-13 theory of operation, 3-20 multiplexed output, single-channel measurements, 5-4 to 5-5[...]

  • Page 157

    Index © National Instruments Corporation Index-7 SCXI-1121 User Manual SCXI-1344 Lab-PC+ cable assembly, E-5 problem-solving and diagnostic resources, online, G-1 programming, 5-1 to 5-17 notation, 5-1 register writes, 5-2 to 5-4 initialization, 5-4 register selection and write procedure, 5-2 to 5-3 SCXI-1121 rear signal connector equivalences (ta[...]

  • Page 158

    Index SCXI-1121 User Manual Index-8 www .natinst.com timing diagram, 2-46 Slot 0 Register description, 4-5 programming hardscan circuitry, 5-13 to 5-14 Slot-Select Register, 4-6 register wri tes, 5-2 to 5-4 RESET* signal (table), 3-4, C-3 Revision A and B parts locator diagram detailed, F-3 general, F-2 photograph, F-1 RTDs specifications for RTD m[...]

  • Page 159

    Index © National Instruments Corporation Index-9 SCXI-1121 User Manual SCXI-1343 rear screw terminal adapter, E-14 to E-16 SCXI-1344 Lab-PC+ cable assembly, E-4 to E-6 SCXI-1350 multichassis adapter, E-12 to E-13 SCXI-1351 one-slot cable extender, E-12 SCXI-1180 feedthrough pan e l, E-8 to E-10 description, E-8 installation, E-9 to E-10 SCXI-1302 [...]

  • Page 160

    Index SCXI-1121 User Manual Index-10 www .natinst.com SERCLK signal. See also communication signals. description (table), 2-38, B-2 register writes, 5-2 to 5-3 SCXIbus to SCXI-1 121 rear signal connector to DAQ board pin equivalences (table), 2-41 timing requirements (figu re), 2-44 SERDATIN signal. See also communication signals. description (tabl[...]

  • Page 161

    Index © National Instruments Corporation Index-11 SCXI-1121 User Manual SCXIbus to SCXI-1 121 rear signal connector to DAQ board pin equivalences (table), 2-41 Slot-Select Register description, 4-6 register writes, 5-2 to 5-4 software, optional, 1-2 to 1-3 software-related resources, G-2 specifications analog input, A-1 to A-2 cold-junction sensor[...]

  • Page 162

    Index SCXI-1121 User Manual Index-12 www .natinst.com W Web support from National Instruments, G-1 to G-2 online problem-solving and diagnostic resources, G-1 software-related resources, G-2 Worldwide technical support, G-2 W xx jumpers. See jumpers.[...]