Instruction/ maintenance manual of the product SCXI-1121 National Instruments
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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.
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 O.
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.
© National Instruments Corporation v SCXI-1121 User Manual Contents About This Manual Conventions ............ ........... ........... ............... ........... ........... ........... ............... ........... ....... x i Related Documentation .
Contents SCXI-1121 User Manual vi www.natinst.com Chapter 3 Theory of Operation Functional Overview ............. ........... ............ .............. ........... ........... ............... ........... ... 3-1 SCXIbus Connector ................. .
Contents © National Instruments Corporation vii SCXI-1121 User Manual 2. Module Programming ................................................................... 5-10 3. Programming the Slot 0 Hardscan Circuitry ................. .............. .. 5-13 4.
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 .......................... ............
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 ..................... .....
© 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.
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.
© 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.
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 .
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.
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 .
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.
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.
© 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.
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.
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 .
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.
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.
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 .
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.
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.
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.
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.
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.
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.
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 E.
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.
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-.
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.
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 .
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.
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 .
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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 i.
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.
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).
Chapter 2 Configuration and Installation SCXI-1121 User Manual 2-34 www .natinst.com Figure 2-11. SCXI-1320 Parts Locator Diagram.
Chapter 2 Configuration and Installation © National Instruments Corporation 2-35 SCXI-1121 User Manual Figure 2-12. SCXI-1328 Parts Locator Diagram.
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.
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 .
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.
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.
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.
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.
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.
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.
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.
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 .
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 .
© 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.
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 circuit.
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.
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.
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.
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.
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 .
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.
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.
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.
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.
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.
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.
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.
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.
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).
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 pa.
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.
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.
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.
© 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.
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.
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.
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.
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.
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.
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.
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.
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.
© 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 .
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.
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 .
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.
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 .
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.
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.
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-6.
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).
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.
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.
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.
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.
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.
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.
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).
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.
© 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) .
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 ............... .........
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 .
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.
© 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 .
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.
© 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.
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.
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.
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.
© 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.
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 .
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.
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.
© 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 assem.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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 .
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.
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.
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 .
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 Co.
© 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.
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.
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.
© 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 .
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.
© 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- 1.
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 c.
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 dire.
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.
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.
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 sc.
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 d.
© 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- signa.
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-.
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 sign.
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 s.
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 a.
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, .
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.
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 .
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,.
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.
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 r.
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.
An important point after buying a device National Instruments SCXI-1121 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought National Instruments SCXI-1121 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data National Instruments SCXI-1121 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, National Instruments SCXI-1121 you will learn all the available features of the product, as well as information on its operation. The information that you get National Instruments SCXI-1121 will certainly help you make a decision on the purchase.
If you already are a holder of National Instruments SCXI-1121, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime National Instruments SCXI-1121.
However, one of the most important roles played by the user manual is to help in solving problems with National Instruments SCXI-1121. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device National Instruments SCXI-1121 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center