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National Instruments SCXI-1120 User Manual

Eight-channel isolated analog input module for signal conditioning
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SCXI-1120

User Manual

Eight-Channel Isolated Analog Input Module for Signal Conditioning
August 1994 Edition
Part Number 320425B-01
© Copyright 1992, 1994 National Instruments Corporation.
All Rights Reserved.

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  • Page 1: User Manual

    SCXI-1120 User Manual Eight-Channel Isolated Analog Input Module for Signal Conditioning August 1994 Edition Part Number 320425B-01 © Copyright 1992, 1994 National Instruments Corporation. All Rights Reserved.
  • Page 2 National Instruments Corporate Headquarters 6504 Bridge Point Parkway Austin, TX 78730-5039 (512) 794-0100 Technical support fax: (800) 328-2203 (512) 794-5678 Branch Offices: Australia (03) 879 9422, Austria (0662) 435986, Belgium 02/757.00.20, Canada (Ontario) (519) 622-9310, Canada (Québec) (514) 694-8521, Denmark 45 76 26 00, Finland (90) 527 2321, France (1) 48 14 24 24, Germany 089/741 31 30, Italy 02/48301892, Japan (03) 3788-1921, Netherlands 03480-33466, Norway 32-848400, Spain (91) 640 0085, Sweden 08-730 49 70, Switzerland 056/20 51 51, U.K.

  • Page 3: Limited Warranty

    The SCXI-1120 is warranted against defects in materials and workmanship for a period of one year from the date of shipment, as evidenced by receipts or other documentation. National Instruments will, at its option, repair or replace equipment that proves to be defective during the warranty period. This warranty includes parts and labor.

  • Page 4: Table Of Contents

    Terminal Block Jumper Configuration ... 2-19 Terminal Block Signal Connection ... 2-20 Terminal Block Installation ... 2-23 Rear Signal Connector ... 2-23 Rear Signal Connector Signal Descriptions ... 2-25 Analog Output Signal Connections... 2-26 © National Instruments Corporation ... 2-1 SCXI-1120 User Manual...
  • Page 5 Chapter 4 Register Descriptions ... 4-1 Register Description... 4-1 Register Description Format ... 4-1 SCXI-1120 Registers ... 4-1 Module ID Register... 4-2 Configuration Register ... 4-3 Slot 0 Register Descriptions... 4-5 Slot-Select Register ... 4-6 Hardscan Control Register (HSCR) ... 4-7 FIFO Register...
  • Page 6 Multiplexed Output ... 5-4 Indirect Measurements ... 5-4 Measurements from Other Modules ... 5-4 Measurements from the SCXI-1120 via Another Module ... 5-4 Scanning Measurements ... 5-5 1. Data Acquisition Board Setup Programming... 5-6 Counter 1 and SCANDIV ... 5-8 2.
  • Page 7 SCXI-1343 Rear Screw Terminal Adapter ... E-11 SCXI-1343 Installation ... E-11 Appendix F Revision A and B Photo and Parts Locator Diagrams Appendix G Customer Communication Glossary ... Glossary-1 Index ... Index-1 SCXI-1120 User Manual ... G-1 viii ... F-1 © National Instruments Corporation...
  • Page 8 Figure 2-9. SCXI-1320 Parts Locator Diagram ... 2-21 Figure 2-10. SCXI-1328 Parts Locator Diagram ... 2-22 Figure 2-11. SCXI-1120 Rear Signal Connector Pin Assignment ... 2-24 Figure 2-12. SCANCLK Timing Requirements ... 2-28 Figure 2-13. Slot-Select Timing Diagram ... 2-29 Figure 2-14.
  • Page 9 Jumper Settings on the SCXI-1320 Terminal Block ... 2-19 Table 2-8. Jumper Settings on the SCXI-1328 Terminal Block ... 2-20 Table 2-9. SCXIbus to SCXI-1120 Rear Signal Connector to Data Acquisition Board Pin Equivalences ... 2-27 Table 3-1. SCXIbus Equivalents for the Rear Signal Connector ... 3-5 Table 3-2.

  • Page 10: About This Manual

    Refer to your chassis manual for a description of the different module classes. Each channel is isolated and independently configurable via jumpers. Refer to your chassis manual for a description of the different module classes. The SCXI-1120 is a member of the National Instruments Signal Conditioning eXtensions for Instrumentation (SCXI) Series for the National Instruments data acquisition plug-in boards.

  • Page 11: Conventions Used In This Manual

    SCXI-1120. • Appendix F, Revision A and B Photo and Parts Locator Diagrams, contains a photograph of the Revision A and B SCXI-1120 signal conditioning module and the general and detailed parts locator diagrams. • Appendix G, Customer Communication, contains forms you can use to request help from National Instruments or to comment on our products and manuals.

  • Page 12: Related Documentation

    Your SCXI chassis user manual Customer Communication National Instruments wants to receive your comments on our products and manuals. We are interested in the applications you develop with our products, and we want to help if you have problems with them. To make it easy for you to contact us, this manual contains comment and configuration forms for you to complete.

  • Page 13: Chapter 1 Introduction

    If external excitation is provided, thermistors, RTDs, and strain gauges can also be measured. The SCXI-1120 can operate in two output modes–in the Parallel-Output mode with all eight input channels connected in parallel to eight data acquisition board channels, or in the Multiplexed-Output mode with all eight channels multiplexed into a single data acquisition board channel.

  • Page 14: What Your Kit Should Contain

    This manual contains complete instructions for directly programming the SCXI-1120. You can order separate software packages for controlling the SCXI-1120 from National Instruments. When you combine the PC, AT, and MC data acquisition boards with the SCXI-1120, you can use LabVIEW for Windows or LabWindows for DOS. LabVIEW and LabWindows are innovative program development software packages for data acquisition and control applications.

  • Page 15: Optional Equipment

    Chapter 1 You can also use the SCXI-1120, combined with the NB Series data acquisition boards, with NI-DAQ software for Macintosh. NI-DAQ software for Macintosh, which is shipped with all National Instruments Macintosh data acquisition boards, comes with language interfaces for MPW C, THINK C, Pascal, and Microsoft QuickBASIC.

  • Page 16: Custom Cables

    Electronic Products Division/3M (part number 3365/50) • T&B/Ansley Corporation (part number 171-50) The SCXI-1120 front connector is a 32-pin DIN C male connector with columns A and C even pins only. The manufacturer part number used by National Instruments for this connector is as follows: •...

  • Page 17: Configuration And Installation

    This chapter describes the SCXI-1120 jumper configurations, installation of the SCXI-1120 into the SCXI chassis, signal connections to the SCXI-1120, and cable wiring. Module Configuration The SCXI-1120 includes 46 jumpers that are shown in the parts locator diagrams in Figures 2-1 and 2-2. © National Instruments Corporation...

  • Page 18: Figure 2-1. Scxi-1120 General Parts Locator Diagram

    Configuration and Installation Chapter 2 Figure 2-1. SCXI-1120 General Parts Locator Diagram SCXI-1120 User Manual © National Instruments Corporation...

  • Page 19: Figure 2-2. Detailed Parts Locator Diagram

    Chapter 2 Configuration and Installation Figure 2-2 shows a detailed parts locator diagram of the SCXI-1120. Figure 2-2. Detailed Parts Locator Diagram © National Instruments Corporation SCXI-1120 User Manual...

  • Page 20: Digital Signal Connections

    The four digital signal connection jumpers have position 1 marked on the board. Position 3 is not explicitly marked on the board. The SCXI-1120 has three jumpers dedicated for communication between the data acquisition board and the SCXIbus. These jumpers are W42, W43, and W44.

  • Page 21: Jumper W44

    SERDATOUT line. Using Jumpers W42 and W43 If the SCXI-1120 is not cabled to a data acquisition board, the positions of these jumpers do not matter, so leave them in their factory-default positions (both in position 1).

  • Page 22: Table 2-1. Digital Signal Connections, Jumper Settings

    MISO line in only one chassis. Pick one of the chassis that has the SCXI-1120 cabled to the DAQ board. Set jumper W43 on the SCXI-1120 to position 1. On the SCXI-1120s that are in the other chassis and cabled to the data acquisition board, set jumper W43 to position 3.

  • Page 23: Analog Configuration

    (NRSE). Do not use differential-input data acquisition boards when jumper W46 is in the AB-R2 position. Note: The SCXI-1120 will drive pins 4, 6, 8, 10, 12, 14, 16, and 18 on the rear signal connector, although the SCXI-1120 is in pseudodifferential mode.

  • Page 24: Direct Temperature Connection

    Direct Temperature Connection Jumper W41 When your SCXI-1120 is operating with a data acquisition board configured in a differential mode, such as the MIO board, you can access the temperature sensor only in the Multiplexed- Output mode. Direct temperature connection is not permissible to the data acquisition board.

  • Page 25: Gain Jumpers

    10 (position D). To change the gain of your module, move the appropriate jumper on your module to the position indicated in Tables 2-3 and 2-4. Refer to Figure 2-1, SCXI-1120 General Parts Locator Diagram, and Figure 2-2, Detailed Parts Locator Diagram, for jumper locations on your module.

  • Page 26: Filter Jumpers

    Input Channel Number Your SCXI-1120 is shipped in the 4 Hz position. Remember to make sure that both stages are set to the same bandwidth to ensure that the required bandwidth is achieved. Notice that one jumper block is available for each filter stage.

  • Page 27: Hardware Installation

    1. Turn off the computer that contains the data acquisition board or disconnect it from your SCXI chassis. 2. Turn off the SCXI chassis. Do not insert the SCXI-1120 into a chassis that is turned on. 3. Insert the SCXI-1120 into the module guides. Gently guide the module into the back of the slot until the connectors make good contact.

  • Page 28: Front Connector

    Configuration and Installation Front Connector Figure 2-3 shows the pin assignments for the SCXI-1120 front connector. Number Figure 2-3. SCXI-1120 Front Connector Pin Assignment SCXI-1120 User Manual Signal Column Name CH0+ CH1+ CH2+ CH3+ CH4+ CH5+ CH6+ CH7+ RSVD +5 V...

  • Page 29: Front Connector Signal Descriptions

    Figure 2-4 shows how to connect a ground- referenced signal. Figure 2-5 shows how to connect a floating signal. Figures 2-6 and 2-7 show how to connect AC-coupled signals. © National Instruments Corporation Configuration and Installation Description Chassis Ground –...

  • Page 30: Figure 2-4. Ground-Referenced Signal Connection With High Common-Mode Voltage

    Configuration and Installation Figure 2-4. Ground-Referenced Signal Connection with High Common-Mode Voltage Figure 2-5. Floating Signal Connection Referenced to Chassis Ground for Better bias Figure 2-6. Floating AC-Coupled Signal Connection SCXI-1120 User Manual High Module Module Signal-to-Noise Ratio Module 2-14 Chapter 2 ©...

  • Page 31: Temperature Sensor Connection

    Temperature Sensor Connection Pins C2 and C4 are dedicated for connecting the temperature sensor to the SCXI-1120. The temperature sensor is not isolated and is referenced to the chassis ground. The connection is overvoltage protected to 25 VDC with power on and 15 VDC with power off.

  • Page 32: Connector-And-Shell Assembly

    With this kit, you can build your own signal cable to connect to the SCXI-1120 inputs. After you have built the cable, the shell covers and protects the connector. Perform the following steps to assemble and mount the connector-and- shell assembly to your SCXI module: 1.

  • Page 33: Figure 2-8. Assembling And Mounting The Scxi-1330 Connector-And-Shell Assembly

    Figure 2-8. Assembling and Mounting the SCXI-1330 Connector-and-Shell Assembly SCXI-1320 and SCXI-1328 Terminal Blocks The second type of connector available to connect the signals to the SCXI-1120 inputs is a terminal block with an onboard temperature sensor and screw terminals for easy connection.

  • Page 34: Terminal Block Temperature Sensor

    • You can connect the temperature sensor to a separate data acquisition channel via pin 18 on the module rear signal connector when you set SCXI-1120 jumper W41 to position 3. This is the Direct Temperature Sensor (DTS) mode. Note: Use an average of a large number of samples to obtain the most accurate reading.

  • Page 35: Terminal Block Jumper Configuration

    The DTEMP position connects the temperature sensor to SCXI-1120 jumper W41. In both MTS and DTS modes, the reference to the temperature sensor signal is the SCXI-1120 analog ground that is connected to MCHO- in the MTS mode, or to OUTREF or AOGND (with SCXI-1120 jumper W46 set in positions AB-R2 and AB-R0, respectively) in the DTS mode.

  • Page 36: Terminal Block Signal Connection

    6. Snap the top cover back in place. 7. Reinsert the grounding screw to ensure proper shielding. 8. Connect the terminal block to the SCXI-1120 front connector as explained in the Terminal Block Installation section later in this chapter. Figure 2-9 shows a parts locator diagram for the SCXI-1320 terminal block. Figure 2-10 shows a parts locator diagram for the SCXI-1328 terminal block.

  • Page 37: Figure 2-9. Scxi-1320 Parts Locator Diagram

    Chapter 2 Configuration and Installation Figure 2-9. SCXI-1320 Parts Locator Diagram © National Instruments Corporation 2-21 SCXI-1120 User Manual...

  • Page 38: Figure 2-10. Scxi-1328 Parts Locator Diagram

    Configuration and Installation Chapter 2 Figure 2-10. SCXI-1328 Parts Locator Diagram SCXI-1120 User Manual 2-22 © National Instruments Corporation...

  • Page 39: Terminal Block Installation

    To connect the terminal block to the SCXI-1120 front connector, perform the following steps: 1. Connect the SCXI-1120 front connector to its mating connector on the terminal block. 2. Make sure that the SCXI-1120 top and bottom thumbscrews do not obstruct the rear panel of the terminal block.

  • Page 40: Figure 2-11. Scxi-1120 Rear Signal Connector Pin Assignment

    Configuration and Installation Figure 2-11. SCXI-1120 Rear Signal Connector Pin Assignment SCXI-1120 User Manual AOGND AOGND MCH0+ MCH0- MCH1+ MCH1- MCH2- MCH2+ MCH3- 9 10 MCH3+ MCH4- 11 12 MCH4+ MCH5- MCH5+ 13 14 MCH6- MCH6+ 15 16 MCH7- MCH7+...

  • Page 41: Rear Signal Connector Signal Descriptions

    MOSI is being sent to a module or Slot 0. Scan Clock – Indicates to the SCXI-1120 that a sample has been taken by the data acquisition board and causes the SCXI-1120 to change channels.

  • Page 42: Analog Output Signal Connections

    W46 is in position AB-R2. Pins 3 through 18 are the analog output channels of the SCXI-1120. Pins 3 and 4, or MCH0 , are a multiplexed output of all eight channels and the temperature sensor output. Pins 5 through 18, or MCH1 through MCH7 , are a parallel connection of channels 1 through 7 to the rear signal connector.

  • Page 43: Table 2-9. Scxibus To Scxi-1120 Rear Signal Connector To Data Acquisition Board Pin Equivalences

    Pin 26 is SERDATOUT and is equivalent to SCXIbus MISO when jumper W43 is in position 1. The digital I/O signals of the SCXI-1120 match the digital I/O lines of the MIO-16 board. When used with an SCXI-1341, SCXI-1342, or SCXI-1344 cable assembly, the SCXI-1120 signals match the digital lines of the Lab-NB/Lab-PC+/Lab-LC boards and the PC-LPM-16 board, respectively.

  • Page 44: Timing Requirements And Communication Protocol

    Chassis 9. Notice that the factory-default chassis address for the SCXI-1000 is address 0. For information on changing the address of your chassis, consult the SCXI-1000/1001 User Manual. An SCXI-1000 chassis will respond to any chassis number. SCXI-1120 User Manual Time low before rising edge Time high before falling edge...

  • Page 45: Figure 2-13. Slot-Select Timing Diagram

    Slot-Select Register to ensure that no accidental writes occur. Figure 2-14 shows the timing requirements on the SERCLK and SERDATIN signals. You must observe these timing requirements for all communications. T SCXI-1120. © National Instruments Corporation Configuration and Installation Chassis ID = 9 Slot 11...

  • Page 46: Figure 2-14. Serial Data Timing Diagram

    Figure 2-14. Serial Data Timing Diagram After the Slot-Select line to an SCXI-1120 has been asserted, you can write to its Configuration Register and read from its Module ID Register using the following protocols. The contents of the Module ID Register are reinitialized by deasserting Slot-Select. After the 32 bits of data are read from the Module ID Register, further data will be zeros until reinitialization occurs.

  • Page 47: Figure 2-15. Configuration Register Write Timing Diagram

    3. Pull SLOT0SEL* low to deassert the SS* line and establish conditions for writing a new slot-select number to the Slot 0 Slot-Select Register. 4. If you are not selecting another slot, you should write zero to the Slot 0 Slot-Select Register. Figure 2-16 illustrates a read of the SCXI-1120 Module ID Register. SLOT0SEL* SERCLK...

  • Page 48: Chapter 3 Theory Of Operation

    Chapter 3 Theory of Operation This chapter contains a functional overview of the SCXI-1120 module and explains the operation of each functional unit making up the SCXI-1120. Functional Overview The block diagram in Figure 3-1 illustrates the key functional components of the SCXI-1120.

  • Page 49: Scxibus Connector

    • Timing and analog circuitry The SCXI-1120 consists of eight isolated amplifier channels with gains of 1, 2, 5, 10, 20, 50, 100, 200, 500, 1,000, and 2,000. The SCXI-1120 also has a digital section for automatic control of channel scanning, temperature selection, and MUXCOUNTER clock selection.

  • Page 50: Figure 3-2. Scxibus Connector Pin Assignment

    GUARD GUARD GUARD GUARD GUARD GUARD RESET* MISO CHSGND CHSGND +5 V SPICLK TRIG0 Figure 3-2. SCXIbus Connector Pin Assignment © National Instruments Corporation CHSGND CHSGND CHSGND CHSGND CHSGND CHSGND CHSGND SCANCON Theory of Operation GUARD GUARD GUARD AB0- GUARD...

  • Page 51: Scxibus Connector Signal Descriptions

    A22, B22, C22, V+ A23, D23 +5 V SPICLK MOSI SCXI-1120 User Manual Description Guard – Shields and guards the analog bus lines from noise. Analog Bus 0+ – Positive analog bus 0 line. Used to multiplex several modules to one analog signal.

  • Page 52: Table 3-1. Scxibus Equivalents For The Rear Signal Connector

    SERCLK SERDATOUT The SCXI-1120 module converts the data acquisition board signals to open-collector signals on the backplane of the SCXI chassis. In order for the data acquisition board to talk to a slot, the board must first assert the SS* for that slot. This is done by asserting INTR* low, writing a 16-bit number over MOSI corresponding to the desired slot (and chassis if an SCXI-1001 chassis is being used), and then releasing INTR* high.

  • Page 53: Digital Interface

    The digital interface circuitry is divided into a data acquisition section and an SCXIbus section. The SCXI-1120 connects to the SCXIbus via a 4x24 metral receptacle and to the data acquisition board via a 50-pin ribbon-cable header. The digital interface circuitry buffers the digital signals from the data acquisition board and the SCXIbus and sends signals back and forth between the data acquisition board and the SCXIbus.

  • Page 54: Digital Control Circuitry

    (D*/A low). The Configuration Register provides channel selection and configures the SCXI-1120 for scanning options. All the control bits are fed into a latch before being routed to the rest of the module. The channel-select bits are taken directly from the shift register.

  • Page 55: Analog And Timing Circuitry

    The SCXI-1120 module ID is hex 00000004. Analog and Timing Circuitry The SCXIbus provides analog power ( 18.5 VDC) that is regulated on the SCXI-1120 to 15 VDC, a guard, an analog bus (AB0 ), and a chassis ground (CHSGND). AB0 buses the SCXI-1120 output to other modules or receives outputs from other modules via the SCXIbus.

  • Page 56: Figure 3-5. Analog Input Block Diagram

    Chapter 3 Figure 3-5. Analog Input Block Diagram © National Instruments Corporation Input Channel 0 Input Channel 1 Input Channel 2 Input Channel 3 Input Channel 4 Input Channel 5 Input Channel 6 Input Channel 7 MTEMP DTEMP Theory of Operation...

  • Page 57: Calibration

    Calibration Calibration Equipment Requirements For best measurement results, calibrate the SCXI-1120 so that its offset is adjusted to 0 3 mV RTO and 0 6 V RTI. No special equipment is needed other than a regular voltmeter with the following specifications.

  • Page 58: Offset Null Adjust

    We will refer to the measuring instrument as a digital multimeter (DMM). Each channel on the SCXI-1120 has two potentiometers dedicated for calibration. One potentiometer is used to null the output offset; the other is used to null the input offset.

  • Page 59: Analog Output Circuitry

    Theory of Operation Table 3-2. Calibration Potentiometers Reference Designators Input Channel Number Analog Output Circuitry Figure 3-6 shows the SCXI-1120 analog output circuitry. Channel 0 • • • Channel 7 MTEMP Output Stage and Hardware Scan Control Analog Reference SCXI-1120 User Manual...

  • Page 60: Scanning Modes

    Notice that when the Multiplexed-Output mode is selected, pins 5 through 18 on the rear signal connector are still driven by the SCXI-1120. The SCXI-1120 outputs on the rear signal connector are short-circuit protected.

  • Page 61: Single-Module Parallel Scanning

    National Instruments. Single-Module Parallel Scanning Single-module parallel scanning is the simplest scanning mode. Directly cable the SCXI-1120 to the data acquisition board as shown in Figure 3-7. In this configuration, each analog signal has its own channel. Timing signals are not necessary for this type of scanning because the module provides all channels to the data acquisition board at all times.

  • Page 62: Single-Module Multiplexed Scanning (Indirect)

    Figure 3-8. Single-Module Multiplexed Scanning (Direct) Single-Module Multiplexed Scanning (Indirect) In this mode, the SCXI-1120 is not directly cabled to the data acquisition board. Instead, you connect another module to the data acquisition board, and the analog output of the SCXI-1120 is sent over Analog Bus 0, through the intermediate module, and then to the data acquisition board.

  • Page 63: Multiple-Chassis Scanning

    SCXI-1001 chassis and MIO-16 data acquisition boards. See Chapter 5, Programming, for more information on multiple-chassis scanning. See Appendix E, SCXI-1120 Cabling, for more information on the necessary cable accessories for multichassis scanning. Data Acquisition Board...

  • Page 64: Register Descriptions

    SCXI-1120 Registers The SCXI-1120 has two registers. The Module ID Register is a four-byte, read-only register that contains the Module ID number of the SCXI-1120. The Configuration Register is a 16-bit, write-only register that controls the functions and characteristics of the SCXI-1120.

  • Page 65: Module Id Register

    The bytes will appear least significant byte first. Within each byte, data is sent out MSB first. Additional data transfers will result in all zeros being sent on the MISO line. The Module ID Register is reinitialized to its original value each time the SCXI-1120 is deselected by the SS* signal on the backplane.

  • Page 66: Configuration Register

    SS* is asserted (low) and D*/A indicates data (low), the register will shift in the data present on the MOSI line, bit 15 first, and then latch it when the SCXI-1120 is deselected by the SS* signal on the backplane. The Configuration Register initializes to all zeros when the SCXI chassis is reset or first turned on.
  • Page 67 SCANCONEN bit is cleared. If the selected channel output or MTEMP is driving the output buffer, it will drive Analog Bus 0 if AB0EN is set. If nothing is driving the output buffer, the SCXI-1120 output will saturate. © National Instruments Corporation Chapter 4...

  • Page 68: Slot 0 Register Descriptions

    Slot-Select Register exists in a system composed of multiple chassis. The HSCR and FIFO Register, on the other hand, are unique to each chassis and you must program them separately. © National Instruments Corporation SCXI-1120 User Manual...

  • Page 69: Slot-Select Register

    CHS3 CHS2 CHS1 Name 15-9 CHS<4..0> SL<3..0> SCXI-1120 User Manual CHS0 Description Don't care bits – Unused. Chassis Bit 4 through 0 – These bits determine which chassis is selected. On the SCXI-1000 chassis, these are don't care bits. Slot Bit 3 through 0 – These bits determine which slot in the selected chassis is selected.

  • Page 70: Hardscan Control Register (Hscr)

    RSVD Name RSVD ONCE HSRS* LOAD* SCANCONEN CLKEN © National Instruments Corporation ONCE HSRS* LOAD* Description Reserved. Forced Retransmit – This bit, when clear, causes the scan list in the FIFO to be reinitialized to the first entry, thus allowing the scan list to be reprogrammed in two steps instead of having to rewrite the entire list.

  • Page 71: Fifo Register

    MOD0 CNT6 CNT5 Name 15-11 10-7 MOD<3..0> CNT<6..0> SCXI-1120 User Manual MOD3 CNT4 CNT3 CNT2 Description Don't care bits – Unused. Module Number – The value of these bits plus one determines the number of the slot to be accessed for this scan entry.

  • Page 72: Chapter 5 Programming

    Chapter 5 Programming This chapter contains a functional programming description of the SCXI-1120 and Slot 0. Note: If you plan to use a programming software package such as NI-DAQ, LabWindows, or LabVIEW with your SCXI-1120 board, you do not need to read this chapter.

  • Page 73: Register Selection And Write Procedure

    Programming Table 5-1. SCXI-1120 Rear Signal Connector Pin Equivalences SCXIbus Line SCXI-1120 Rear Signal Connector MOSI SERDATIN D*/A DAQD*/A INTR* SLOT0SEL* SPICLK SERCLK MISO SERDATOUT Register Selection and Write Procedure 1. Select the slot of the module to be written to (or Slot 13 or 14). Initial conditions: SERDATIN = X.

  • Page 74: Initialization

    SCXI-1120. To measure one of the eight differential input channels to the SCXI-1120, or the DTEMP line if the module has been configured appropriately, perform the following steps: 1.

  • Page 75: Multiplexed Output

    AB0. 2. Write the binary pattern 00XXXXXX XX100011 to the SCXI-1120 Configuration Register. This step disables the SCXI-1120 from driving Analog Bus 0 and allows Analog Bus 0 to drive MCH0 through the output buffer. 3. Program the other module to drive Analog Bus 0 with the signal to be measured.

  • Page 76: Scanning Measurements

    Chapter 5 To measure one of the eight differential input channels to the SCXI-1120, perform the following steps: 1. Perform any necessary programming to ensure that no modules are driving Analog Bus 0. For an SCXI-1120, clearing AB0EN in the Configuration Register will ensure that its output is not driving AB0.

  • Page 77: Data Acquisition Board Setup Programming

    Programming Multiple A/D Conversions with Channel Scanning • Lab-PC+ User Manual Programming Multiple A/D Conversions with Channel Scanning Programming Multiple A/D Conversions with Interval Scanning Programming Multiple A/D Conversions in Single-Channel Interval Acquisition Mode SCXI-1120 User Manual © National Instruments Corporation Chapter 5...
  • Page 78 Although you may be using only one MIO board channel, the channel scanning programming will ensure that the MIO board outputs SCANCLK, which is needed by the SCXI-1120 and Slot 0.

  • Page 79: Counter 1 And Scandiv

    See Chapter 2, Configuration and Installation, for more information. To program the SCXI-1120 for single-module parallel scanning, write the binary pattern 00XXXX00 XX000000 to the SCXI-1120 Configuration Register. Notice that this can be the RESET state. SCXI-1120 User Manual ©...

  • Page 80: Single-Module Multiplexed Scanning (Direct)

    AB0. 2. Write the binary pattern 10XXXXXX XX100011 to the SCXI-1120 Configuration Register. This step disables the SCXI-1120 from driving Analog Bus 0 and allows Analog Bus 0 to drive MCH0 through the output buffer. 3. Program the other module to be scanned.

  • Page 81: Multiple-Chassis Scanning

    10XXXCCC XX001111 to its Configuration Register. Note: If this module is an SCXI-1120 and is not going to be scanned (it is just being used as an interface), write a 0 to bit 2 (SCANCONEN) in the Configuration Register. The start channel bits become don't care bits.
  • Page 82 Select another slot or toggle the SLOT0SEL* line to temporarily deassert the appropriate SS* line. If consecutive scan list entries access an SCXI-1120, the module will reload the MUXCOUNTER with the starting channel after each entry. Thus, two entries with counts of four for one module will yield different behavior than one entry with a count of eight.

  • Page 83: Acquisition Enable, Triggering, And Servicing

    FIFO Register in Chapter 4, Register Descriptions. Example 1 You want to scan, in Multiplexed mode, channels 1 through 4 on an SCXI-1120 in Slot 1 of an SCXI-1000 chassis. The SCXI-1120 is directly cabled to a data acquisition board.

  • Page 84: Example 2

    Slot 4 is cabled to the data acquisition board. You want to scan channels 3 through 7 on the SCXI-1120 in Slot 1, channels 0 through 6 on the SCXI-1120 in Slot 4, and channels 7 through 3 on the SCXI-1120 in Slot 3.

  • Page 85: Example 3

    Example 3 You want to scan five channels on an SCXI-1120 in Slot 4 of Chassis 1, then seven channels of an SCXI-1120 in Slot 11 of Chassis 2, three channels of an SCXI-1120 in Slot 3 in Chassis 3, and one channel of an SCXI-1120 in Slot 8 of Chassis 3.
  • Page 86 Chapter 5 13. Toggle SLOT0SEL*. 14. Write XXXXX001 00000010 over MOSI. 15. Toggle SLOT0SEL*. 16. Write XXXXX011 10000000 over MOSI. 17. Select Slot 0 in Chassis 0. © National Instruments Corporation 5-15 SCXI-1120 User Manual Programming...

  • Page 87: Appendix A Specifications

    Appendix A Specifications This appendix lists the specifications for the SCXI-1120. These are typical at 25 C unless otherwise stated. The operating temperature range is 0 to 50 C. Analog Input Gain (jumper-selectable) Output range Number of channels Gain accuracy...

  • Page 88: Cold-Junction Sensor

    SCXI-1328 Accuracy Output Includes the combined effects of the SCXI-1120 and the AT-MIO-16F-5 Includes the combined effects of the SCXI-1120 and the AT-MIO-16X Located on the SCXI-1320 and SCXI-1328 terminal blocks Includes the combined effects of the temperature sensor accuracy and the temperature difference between the...

  • Page 89: Physical

    Dimensions Connectors Operating Environment Temperature Relative humidity Storage Environment Temperature Relative humidity © National Instruments Corporation c lnR TEMPOUT 2.5 V TEMPOUT 1.2 by 6.8 by 8.0 in. 50-pin male ribbon-cable rear connector 32-pin DIN C male front connector (18-screw terminal adapter available)

  • Page 90: Appendix B Rear Signal Connector

    Appendix B Rear Signal Connector This appendix describes the pinout and signal names for the SCXI-1120 50-pin rear signal connector, including a description of each connection. Figure B-1 shows the pin assignments for the SCXI-1120 rear signal connector. Figure B-1. SCXI-1120 Rear Signal Connector Pin Assignment ©...

  • Page 91: Rear Signal Connector Signal Descriptions

    MOSI is being sent to a module or Slot 0. Scan Clock – Indicates to the SCXI-1120 that a sample has been taken by the data acquisition board and causes the SCXI-1120 to change channels.
  • Page 92 Appendix B Rear Signal Connector See the Timing Requirements and Communication Protocol section in Chapter 2, Configuration and Installation, for more detailed information on timing. Detailed signal specifications are also included in Chapter 2. © National Instruments Corporation SCXI-1120 User Manual...

  • Page 93: Appendix Cscxibus Connector

    Appendix C SCXIbus Connector This appendix describes the pinout and signal names for the SCXI-1120 96-pin SCXIbus connector, including a description of each connection. Figure C-1 shows the pinout of the SCXI-1120 SCXIbus connector. © National Instruments Corporation SCXI-1120 User Manual...

  • Page 94: Figure C-1. Scxibus Connector Pin Assignment

    GUARD GUARD GUARD GUARD GUARD GUARD RESET* MISO CHSGND CHSGND +5 V SPICLK TRIG0 Figure C-1. SCXIbus Connector Pin Assignment SCXI-1120 User Manual CHSGND CHSGND CHSGND CHSGND CHSGND CHSGND CHSGND SCANCON © National Instruments Corporation Appendix C GUARD GUARD GUARD...

  • Page 95: Scxibus Connector Signal Descriptions

    A22, B22, C22, V+ A23, D23 +5 V SPICLK MOSI © National Instruments Corporation Description Guard – Shields and guards the analog bus lines from noise. Analog Bus 0+ – Positive analog bus 0 line. Used to multiplex several modules to one analog signal.
  • Page 96 Further information is given in Chapter 3, Theory of Operation. SCXI-1120 User Manual Description (continued) TRIG0 – General-purpose trigger line used by the SCXI-1120 to send SCANCLK to other modules or receive SCANCLK from other modules. Open collector. I/O. Slot Select – When low, enables module communications over the SCXIbus.

  • Page 97: Scxi-1120 Front Connector

    Appendix D SCXI-1120 Front Connector This appendix describes the pinout and signal names for the SCXI-1120 front connector, including a description of each connection. Figure D-1 shows the pin assignments for the SCXI-1120 front connector. Number Figure D-1. SCXI-1120 Front Connector Pin Assignment ©...

  • Page 98: Front Connector Signal Descriptions

    SCXI-1120 Front Connector Front Connector Signal Descriptions Signal Name CHSGND DTEMP +5 V MTEMP A6, C6, C8 RSVD A8, A10, C10, No Connect A16, C16,A22, C22, A28, C28 A12, A14, A18, CH7+ through CH0+ A26, A20, A24, A30, A32 C12, C14, C18, CH7- through CH0-...

  • Page 99: Appendix Escxi-1120 Cabling

    Appendix E SCXI-1120 Cabling This appendix describes how to use and install the hardware accessories for the SCXI-1120: • SCXI-1340 cable assembly • SCXI-1341 Lab-NB, Lab-PC, and Lab-PC+ cable assembly • SCXI-1342 PC-LPM-16 cable assembly • SCXI-1344 Lab-LC cable assembly •...

  • Page 100: Scxi-1340 Installation

    SCXI-1120 Cabling Table E-1 lists the pin equivalences of the MIO-16 board and the SCXI-1120. Table E-1. SCXI-1120 and MIO-16 Board Pinout Equivalences SCXI-1120 Rear Signal Connector 24, 33 No other pins are connected on the SCXI-1120. SCXI-1340 Installation Follow these steps to install the SCXI-1340: 1.

  • Page 101: Scxi-1341 Lab-Nb, Lab-Pc, Or Lab-Pc+ And Scxi-1344 Lab-Lc Cable Assembly

    The adapter board converts the signals from the Lab board I/O connector to a format compatible with the SCXI-1120 rear signal connector pinout at the front connector of the SCXI-1341 or SCXI-1344. The adapter board also has an additional male breakout connector that makes the unmodified Lab board signals accessible to an SCXI-1180 feedthrough panel or an SCXI-1181 breadboard module.

  • Page 102: Scxi-1341 And Scxi-1344 Installation

    Lab Board Pin Lab Board Signal 13, 50 All other pins of the Lab board pinout are not sent to the SCXI-1120 rear signal connector. SCXI-1341 and SCXI-1344 Installation Follow these steps to install the SCXI-1341 or SCXI-1344: 1. Make sure that the computer and the SCXI chassis are turned off.

  • Page 103: Scxi-1342 Pc-Lpm-16 Cable Assembly

    PC-LPM-16 board to the adapter board. The adapter board converts the signals from the PC-LPM-16 I/O connector to a format compatible with the SCXI-1120 rear signal connector pinout. The adapter board also has an additional male breakout connector that makes the unmodified PC-LPM-16 signals accessible to an SCXI-1180 feedthrough panel or SCXI-1181 breadboard module.

  • Page 104: Scxi-1342 Installation

    Table E-3. SCXI-1342 Pin Translations (Continued) PC-LPM-16 Pin PC-LPM-16 Signal All other pins of the PC-LPM-16 pinout are not sent to the SCXI-1120 rear signal connector. SCXI-1342 Installation Follow these steps to install the SCXI-1342: 1. Make sure that the computer and the SCXI chassis are turned off.

  • Page 105: Figure E-2. Scxi-1180 Rear Connections

    4. Screw in the rear panel to the threaded strip in the rear of the chassis. 5. Screw the front panel into the front threaded strip, as shown in Figure E-3. Check the installation. © National Instruments Corporation Threaded Strip in Rear of Chassis...

  • Page 106: Scxi-1302 50-Pin Terminal Block

    5. Tighten the large strain-relief screws to secure the wires. 6. Snap the cover back in place. 7. Reinsert the rear grounding screw. The terminal block is now ready to be connected to the front panel connector. SCXI-1120 User Manual Ribbon Cable to Rear and Breakout Connectors...

  • Page 107: Scxi-1302 Installation

    SCXI-1351 has a female mounting bracket connector that mates with the rear signal connector of a module, and also has a male breakout connector on the ribbon cable for connecting to a feedthrough panel or more cable extenders. © National Instruments Corporation Grounding Screw...

  • Page 108: Scxi-1351 Installation

    2. Insert all the modules in all the chassis. 3. Connect one end of a ribbon cable to the MIO board. 4. Connect the other end of the ribbon cable to the rear connector of the first SCXI-1350. SCXI-1120 User Manual E-10 © National Instruments Corporation...

  • Page 109: Scxi-1343 Rear Screw Terminal Adapter

    SCXI-1343 Rear Screw Terminal Adapter You use the SCXI-1343 universal adapter to adapt custom wiring to the SCXI-1120. The SCXI-1343 has screw terminals for the analog output connections and solder pads for the rest of the signals. A strain-relief clamp is on the outside of the rear panel.

  • Page 110: Table E-4. Scxi-1343 Pin Connections

    SCXI-1120 Cabling Table E-4. SCXI-1343 Pin Connections Rear Signal Connector Pin 24, 33 34-35 SCXI-1120 User Manual SCXI-1120 Use Connection Type AOGND Solder pad AOGND Screw terminal MCH0+ Screw terminal MCH0- Screw terminal MCH1+ Screw terminal MCH1- Screw terminal MCH2+...

  • Page 111: Revision A And B Photo And Parts Locator Diagrams

    This appendix contains a photograph of the Revision A and B SCXI-1120 signal conditioning module and the general and detailed parts locator diagrams. Figure F-1 shows the Revision A and B SCXI-1120 signal conditioning module. Figures F-2 and F-3 show the general and detailed parts locator diagrams.

  • Page 112: Figure F-2. Revision A And B Scxi-1120 General Parts Locator Diagram

    Revision A and B Photo and Parts Locator Diagrams Appendix F Figure F-2. Revision A and B SCXI-1120 General Parts Locator Diagram SCXI-1120 User Manual © National Instruments Corporation...

  • Page 113: Figure F-3. Revision A And B Scxi-1120 Detailed Parts Locator Diagram

    Appendix F Revision A and B Photo and Parts Locator Diagrams Figure F-3. Revision A and B SCXI-1120 Detailed Parts Locator Diagram © National Instruments Corporation SCXI-1120 User Manual...

  • Page 114: Appendix G Customer Communication

    Filling out a copy of the Technical Support Form before contacting National Instruments helps us help you better and faster. National Instruments provides comprehensive technical assistance around the world. In the U.S. and Canada, applications engineers are available Monday through Friday from 8:00 a.m. to 6:00 p.m.

  • Page 115: Technical Support Form

    National Instruments for technical support helps our applications engineers answer your questions more efficiently. If you are using any National Instruments hardware or software products related to this problem, include the configuration forms from their user manuals. Include additional pages if necessary.
  • Page 116 Completing this form accurately before contacting National Instruments for technical support helps our applications engineers answer your questions more efficiently.

  • Page 117: Documentation Comment Form

    Documentation Comment Form National Instruments encourages you to comment on the documentation supplied with our products. This information helps us provide quality products to meet your needs. Title: SCXI-1120 User Manual Edition Date: August 1994 Part Number: 320425B-01 Please comment on the completeness, clarity, and organization of the manual.

  • Page 118: Glossary

    Chassis bit CHSGND Chassis Ground signal cold-junction reference CLKEN Clock Enable bit CLKOUTEN Scan Clock Output Enable bit CLKSELECT Scan Clock Select bit Count bit © National Instruments Corporation Meaning pico- nano- micro- milli- kilo- mega- Glossary-1 Value SCXI-1120 User Manual...
  • Page 119 GBWP gain bandwidth product GUARD Guard signal hexadecimal HSCR Hardscan Control Register HSRS* Hardscan Reset bit hertz input current leakage inches INTR* Interrupt signal input/output kelvin LOAD* Load bit least significant bit SCXI-1120 User Manual Glossary-2 © National Instruments Corporation...
  • Page 120 Real-Time System Integration SCANCLK Scan Clock signal SCANCLKEN Scan Clock Enable bit SCANCON Scanning Control signal SCANCONEN Scan Control Enable bit SCXI Signal Conditioning eXtensions for Instrumentation (bus) Software Developer's Kit © National Instruments Corporation Glossary-3 Glossary SCXI-1120 User Manual...
  • Page 121 Positive Analog Supply signal Negative Analog Supply signal volts direct current input logic high voltage input logic low voltage output logic high voltage output logic low voltage Vrms volts, root mean square watts SCXI-1120 User Manual Glossary-4 © National Instruments Corporation...

  • Page 122: Index

    3-8 to 3-10 analog input specifications, A-1 to A-2 analog output circuitry, 3-12 to 3-13 analog output signal connections, 2-26 SCXI-1120 User Manual AOGND signal analog output signal connections, 2-26 rear signal connector, 2-25, B-2 bit descriptions AB0EN, 4-4 CHAN<2..0>, 4-3...
  • Page 123 Index SCXI-1120 and MIO-16 board pinout equivalences, E-2 SCXI-1341 cable assembly, E-3 to E-4 installation, E-4 to E-5 SCXI-1342 cable assembly, E-5 to E-6 installation, E-6 SCXI-1343 rear screw terminal adapter installation, E-11 pin connections, E-12 SCXI-1344 cable assembly, E-3 to E-4...
  • Page 124 3-7 to 3-8 digital I/O signal connections rear signal connector, 2-26 to 2-27 SCXIbus pin equivalences with SCXI-1120 and data acquisition boards, 2-27 specifications and ratings, 2-27 digital interface circuitry, 3-6 digital signal connections, 2-4 to 2-7...
  • Page 125 4-2 theory of operation, 3-8 timing diagram, 2-31 module programming, 5-8 to 5-10 channel scanning from other modules, 5-9 channel scanning from SCXI-1120 via another module, 5-9 multiple-chassis scanning, 5-10 multiple-module multiplexed scanning, 5-9 to 5-10 single-module multiplexed scanning...
  • Page 126 NI-DAQ software, 1-2 to 1-3 nulling the offset, 3-11 ONCE bit, 4-7 operating environment specifications, A-3 operation of SCXI-1120. See theory of operation. OUTREF signal analog output signal connections, 2-26 jumper connection, 2-7 to 2-8 rear signal connector, 2-25, B-2 parallel scanning, single-module, 3-14, 5-8 PC-LPM-16 cable assembly.
  • Page 127 (HSCR), 4-7 Slot-Select Register, 4-6 RESET* signal description of, 3-4, C-3 initialization, 5-3 and SPI bus, 3-5 Revision A and B SCXI-1120 signal conditioning module detailed parts locator diagram, F-3 general parts locator diagram, F-2 photograph, F-1 RSVD bit, 4-4, 4-7...
  • Page 128 2-18 to 2-19 warnings, 2-18 SCXI-1330 connector-and-shell assembly, 2-16 to 2-17 SCXI-1340 cable assembly, E-1 to E-2 installation, E-2 to E-3 SCXI-1120 and MIO-16 board pinout equivalences, E-2 SCXI-1341 cable assembly, E-3 to E-4 installation, E-4 to E-5 pin equivalences, E-4 SCXI-1342...
  • Page 129 2-11 single-channel measurements, 5-3 to 5-5 direct measurements, 5-3 to 5-4 indirect measurements, 5-4 to 5-5 measurements from other modules, 5-4 measurements from SCXI-1120 via another module, 5-4 to 5-5 multiplexed output, 5-4 parallel output, 5-3 single-module multiplexed scanning...
  • Page 130 3-5 pin assignments, 3-3 signal descriptions, 3-4 to 3-5 timing signal (SCANCLK), 2-28 TRIG0 signal, 3-5, C-4 unpacking the SCXI-1120, 1-4 V- signal, 3-4, C-3 V+ signal, 3-4, C-3 SCXI-1120 User Manual Index-9 © National Instruments Corporation...

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