National Instruments DAQPAD-1200 User Manual

DAQPadTM-1200

User Manual

Data Acquisition and Control for the Parallel Port

November 1995 Edition

Part Number 371351A-01

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 9 879 9422, Austria 0662 45 79 90 0, 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, Hong Kong 2645 3186, Italy 02 48301892, Japan 03 5472 2970, Korea 02 596 7456, Mexico 95 800 010 0793, Netherlands 03480 433466, Norway 32 84 84 00, Singapore 2265886, Spain 91 640 0085, Sweden 08 730 49 70, Switzerland 056 200 51 51, Taiwan 02 377 1200, U.K. 01635 523545

Limited Warranty

The DAQPad-1200 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.

The media on which you receive National Instruments software are warranted not to fail to execute programming instructions, due to defects in materials and workmanship, for a period of 90 days from date of shipment, as evidenced by receipts or other documentation. National Instruments will, at its option, repair or replace software media that do not execute programming instructions if National Instruments receives notice of such defects during the warranty period. National Instruments does not warrant that the operation of the software shall be uninterrupted or error free.

A Return Material Authorization (RMA) number must be obtained from the factory and clearly marked on the outside of the package before any equipment will be accepted for warranty work. National Instruments will pay the shipping costs of returning to the owner parts which are covered by warranty.

National Instruments believes that the information in this manual is accurate. The document has been carefully reviewed for technical accuracy. In the event that technical or typographical errors exist, National Instruments reserves the right to make changes to subsequent editions of this document without prior notice to holders of this edition. The reader should consult National Instruments if errors are suspected. In no event shall National Instruments be liable for any damages arising out of or related to this document or the information contained in it.

EXCEPT AS SPECIFIED HEREIN, NATIONAL INSTRUMENTS MAKES NO WARRANTIES, EXPRESS OR IMPLIED,

AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. CUSTOMER’S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER.

NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA, PROFITS,

USE OF PRODUCTS, OR INCIDENTAL OR CONSEQUENTIAL DAMAGES, EVEN IF ADVISED OF THE POSSIBILITY THEREOF. This limitation of the liability of National Instruments will apply regardless of the form of action,

whether in contract or tort, including negligence. Any action against National Instruments must be brought within one year after the cause of action accrues. National Instruments shall not be liable for any delay in performance due to causes beyond its reasonable control. The warranty provided herein does not cover damages, defects, malfunctions, or service failures caused by owner’s failure to follow the National Instruments installation, operation, or maintenance instructions; owner’s modification of the product; owner’s abuse, misuse, or negligent acts; and power failure or surges, fire, flood, accident, actions of third parties, or other events outside reasonable control.

Copyright

Under the copyright laws, this publication may not be reproduced or transmitted in any form, electronic or mechanical, including photocopying, recording, storing in an information retrieval system, or translating, in whole or in part, without the prior written consent of National Instruments Corporation.

Trademarks

LabVIEW®, NI-DAQ

Product and company names listed are trademarks or trade names of their respective companies.

, and RTSI

are trademarks of National Instruments Corporation.

WARNING REGARDING MEDICAL AND CLINICAL USE

OF NATIONAL INSTRUMENTS PRODUCTS

National Instruments products are not designed with components and testing intended to ensure a level of reliability suitable for use in treatment and diagnosis of humans. Applications of National Instruments products involving medical or clinical treatment can create a potential for accidental injury caused by product failure, or by errors on the part of the user or application designer. Any use or application of National Instruments products for or involving medical or clinical treatment must be performed by properly trained and qualified medical personnel, and all traditional medical safeguards, equipment, and procedures that are appropriate in the particular situation to prevent serious injury or death should always continue to be used when National Instruments products are being used. National Instruments products are NOT intended to be a substitute for any form of established process, procedure, or equipment used to monitor or safeguard human health and safety in medical or clinical treatment.

About This Manual.............................................................................................................ix

Organization of This Manual.........................................................................................ix

Conventions Used in This Manual.................................................................................x

National Instruments Documentation............................................................................x

Related Documentation..................................................................................................xi

Customer Communication.............................................................................................xi

Chapter 1

Introduction..........................................................................................................................1-1

About the DAQPad-1200...............................................................................................1-1

What You Need to Get Started ......................................................................................1-2

Software Programming Choices....................................................................................1-2

LabVIEW and LabWindows/CVI Application Software..................................1-2

NI-DAQ Driver Software...................................................................................1-3

Optional Equipment.......................................................................................................1-4

BP-1 Battery Pack..............................................................................................1-4

Adding an Enhanced Parallel Port (EPP)...........................................................1-4

Custom Cables...................................................................................................1-5

Chapter 2

Installation and Configuration.......................................................................................2-1

Hardware Installation.....................................................................................................2-1

Configuration.................................................................................................................2-1

Parallel Port Configuration................................................................................2-2

Analog I/O Configuration..................................................................................2-2

Analog Output Polarity..........................................................................2-2

Analog Input Polarity.............................................................................2-3

Analog Input Mode................................................................................2-3

RSE Input (Eight Channels, Reset Condition)...........................2-3

NRSE Input (Eight Channels)....................................................2-4

DIFF Input (Four Channels) ......................................................2-4

Chapter 3

Signal Connections.............................................................................................................3-1

Transparent Parallel Port Connector..............................................................................3-1

Front Connector.............................................................................................................3-1

Signal Connection Descriptions.........................................................................3-3

Analog Input Signal Connections......................................................................3-4

Types of Signal Sources.........................................................................3-6

Floating Signal Sources .............................................................3-6

Ground-Referenced Signal Sources...........................................3-6

Input Configurations..............................................................................3-6

Contents

Differential Connection Considerations

(DIFF Configuration).................................................................3-8

Differential Connections for Grounded Signal Sources ............3-8

Differential Connections for Floating Signal Sources...............3-9

Single-Ended Connection Considerations .................................3-10

Single-Ended Connections for Floating Signal Sources

(RSE Configuration)..................................................................3-11

Single-Ended Connections for Grounded Signal Sources

(NRSE Configuration)...............................................................3-12

Common-Mode Signal Rejection Considerations......................3-12

Analog Output Signal Connections....................................................................3-13

Digital I/O Signal Connections..........................................................................3-14

Port C Pin Connections..........................................................................3-16

Timing Specifications............................................................................3-16

Mode 1 Input Timing.................................................................3-17

Mode 1 Output Timing ..............................................................3-18

Mode 2 Bidirectional Timing.....................................................3-19

DAQ and General-Purpose Timing Signal Connections...................................3-19

DAQ Timing Connections.....................................................................3-20

General-Purpose Timing Signal Connections........................................3-23

Power Connections ............................................................................................3-26

Field Wiring Considerations..........................................................................................3-27

Chapter 4

Calibration.............................................................................................................................4-1

Calibration at Higher Gains...........................................................................................4-2

Calibration Equipment Requirements............................................................................4-2

Using the Calibration Function......................................................................................4-2

Appendix A

Specifications........................................................................................................................A-1

Appendix B

Parallel Port Configuration Troubleshooting...........................................................B-1

Appendix C

Customer Communication...............................................................................................C-1

Glossary......................................................................................................................Glossary-1

Index..................................................................................................................................Index-1

DAQPad-1200 User Manual vi © National Instruments Corporation

Contents

Figures

Figure 1-1. The Relationship between the Programming Environment, NI-DAQ,

and Your Hardware............................................................................................1-3

Figure 3-1. DAQPad-1200 Front I/O Connector Pin Assignments......................................3-2

Figure 3-2. DAQPad-1200 Instrumentation Amplifier.........................................................3-5

Figure 3-3. Summary of Analog Input Connections.............................................................3-7

Figure 3-4. Differential Input Connections for Grounded Signal Sources...........................3-9

Figure 3-5. Differential Input Connections for Floating Sources.........................................3-10

Figure 3-6. Single-Ended Input Connections for Floating Signal Sources...........................3-11

Figure 3-7. Single-Ended Input Connections for Grounded Signal Sources........................3-12

Figure 3-8. Analog Output Signal Connections....................................................................3-14

Figure 3-9. Digital I/O Connections.....................................................................................3-15

Figure 3-10. Mode 1 Timing Specifications for Input Transfers............................................3-17

Figure 3-11. Mode 1 Timing Specifications for Output Transfers.........................................3-18

Figure 3-12. Mode 2 Timing Specification for Bidirectional Transfers.................................3-19

Figure 3-13. EXTCONV* Signal Timing...............................................................................3-20

Figure 3-14. Posttrigger DAQ Timing....................................................................................3-21

Figure 3-15. Pretrigger DAQ Timing.....................................................................................3-21

Figure 3-16. Interval-Scanning Signal Timing.......................................................................3-22

Figure 3-17 EXTUPDATE* Signal Timing for Updating DAC Output...............................3-23

Figure 3-18. Event-Counting Application with External Switch Gating................................3-24

Figure 3-19. Frequency Measurement Application................................................................3-25

Figure 3-20. General-Purpose Timing Signals.......................................................................3-26

Tables

Table 2-1. Analog I/O Settings............................................................................................2-2

Table 2-2. Analog Input Modes for the DAQPad-1200......................................................2-3

Table 3-1. Bipolar Analog Input Signal Range Versus Gain..............................................3-4

Table 3-2. Unipolar Analog Input Signal Range Versus Gain............................................3-5

Table 3-3. Port C Signal Assignments................................................................................3-16

About This Manual

This manual describes the electrical and mechanical aspects of the DAQPad-1200 and contains information concerning its operation and programming. The DAQPad-1200 is an independent data acquisition unit that communicates with the PC through the parallel port.

Organization of This Manual

The DAQPad-1200 User Manual is organized as follows:

• Chapter 1, Introduction, describes the DAQPad-1200; lists what you need to get started with your DAQPad-1200; and describes the software programming choices and optional equipment.

• Chapter 2, Installation and Configuration, describes how to install and software configure the DAQPad-1200.

• Chapter 3, Signal Connections, describes the connection of a standard parallel port device to the rear panel transparent parallel port connector, the signal connections to the DAQPad-1200 unit via the DAQPad-1200 front I/O connector, and includes specifications and connection instructions for the DAQPad-1200 connector signals.

• Chapter 4, Calibration, discusses the calibration procedures for the DAQPad-1200 analog I/O circuitry.

• Appendix A, Specifications, lists the DAQPad-1200 specifications.

• Appendix B, Parallel Port Configuration Troubleshooting, contains installation troubleshooting information.

• Appendix C, Customer Communication, contains forms you can use to request help from National Instruments or to comment on our products.

• The Glossary contains an alphabetical list and description of terms used in this manual, including abbreviations, acronyms, metric prefixes, mnemonics, and symbols.

• The Index contains an alphabetical list of key terms and topics in this manual, including the page where you can find each one.

About This Manual

Conventions Used in This Manual

The following conventions are used in this manual: bold italic Bold italic text denotes a note, caution, or warning. italic Italic text denotes emphasis, a cross reference, or an introduction to a key

concept. MC MC refers to the Micro Channel series computers. monospace Lowercase text in this font denotes text or characters that are to be literally

input from the keyboard, sections of code, programming examples, and

syntax examples. This font is also used for the proper names of disk

drives, paths, directories, programs, subprograms, subroutines, device

names, functions, variables, filenames, and extensions, and for statements

and comments taken from program code. NB NB refers to the NuBus series computers. NI-DAQ NI-DAQ is used throughout this manual to refer to the NI-DAQ software

for PC compatibles, unless otherwise noted. PC PC refers to the IBM PC/XT, the IBM PC AT, and compatible computers. Abbreviations, acronyms, metric prefixes, mnemonics, symbols, and terms are listed in the

Glossary.

National Instruments Documentation

The DAQPad-1200 User Manual is one piece of the documentation set for your system. You could have any of several types of manuals, depending on the hardware and software in your system. Use the different types of manuals you have as follows:

• Your DAQ hardware user manuals—These manuals have detailed information about the

DAQ hardware that plugs into or is connected to your computer. Use these manuals for hardware installation and configuration instructions, specification information about your DAQ hardware, and application hints.

• Software manuals—Examples of software manuals you may have are the LabVIEW and

LabWindows® /CVI manual sets and the NI-DAQ manuals. After you set up your hardware system, use either the application software (LabVIEW or LabWindows/CVI) manuals or the NI-DAQ manuals to help you write your application. If you have a large and complicated system, it is worthwhile to look through the software manuals before you configure your hardware.

• Accessory installation guides or manuals—If you are using accessory products, read the

terminal block and cable assembly installation guides or accessory board user manuals. They explain how to physically connect the relevant pieces of the system. Consult these guides when you are making your connections.

DAQPad-1200 User Manual x © National Instruments Corporation

About This Manual

Customer Communication

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

Communication, at the end of this manual.

Chapter 1 Introduction

This chapter describes the DAQPad-1200; lists what you need to get started with your DAQPad-1200; and describes the software programming choices and optional equipment.

About the DAQPad-1200

The DAQPad-1200 is a low-cost high-performance DAQ unit that communicates with the PC through the parallel port on IBM PC/XT/AT and compatible computers. The DAQPad-1200 has eight analog input channels that you can configure as eight single-ended or four differential inputs; a 12-bit successive-approximation ADC; two 12-bit DACs with voltage outputs; 24 lines of TTL-compatible digital I/O; and three 16-bit counter/timers for timing I/O. The DAQPad-1200 is completely software-configurable and self-calibrated. You never need to open the unit to set jumpers or adjust trimpots.

The DAQPad-1200 is register- and pin-compatible with the Lab-PC+ multifunction I/O plug-in board. The DAQPad-1200 is EPP compatible with IEEE 1284, a standard for high-performance PC parallel ports. The DAQPad-1200 works with two different parallel port types–the original Centronics or unidirectional port for printers, and the Enhanced Parallel Port (EPP). The DAQPad-1200 has a second parallel port connector for transparent pass-through connection to a standard parallel port device.

You can power the DAQPad-1200 from the included AC adapter, the optional BP-1 rechargeable DAQPad battery pack, or any 9 to 42 VDC source such as a standard 12 V car battery.

By combining multifunction analog, digital, and timing I/O capabilities in a compact, lightweight unit, the DAQPad-1200 is ideal for portable applications using notebook computers or any PC with a parallel printer port. Because the DAQPad-1200 can take advantage of the high throughput capabilities of the PC parallel port, the unit delivers high-performance data acquisition and control for any application where PC expansion slots are unavailable.

Introduction Chapter 1

What You Need to Get Started

To set up and use your DAQPad-1200, you will need the following:

DAQPad-1200 unit

DAQPad-1200 User Manual

NI-DAQ software for PC compatibles, with manuals Parallel port cable 120 or 230 VAC wall-mount power supply adapter, the BP-1 battery power supply,

or any 9–42 VDC power supply IBM PC/XT/AT or compatible computer

Detailed specifications of the DAQPad-1200 are listed in Appendix A, Specifications.

Software Programming Choices

There are four options to choose from when programming your National Instruments DAQ and SCXI hardware. You can use LabVIEW, LabWindows/CVI, or NI-DAQ.

The DAQPad-1200 works with LabVIEW for Windows, LabWindows/CVI for Windows, and the NI-DAQ software for PC compatibles.

LabVIEW and LabWindows/CVI Application Software

LabVIEW and LabWindows/CVI are innovative program development software packages for data acquisition and control applications. LabVIEW uses graphical programming, whereas LabWindows/CVI enhances traditional programming languages. Both packages include extensive libraries for data acquisition, instrument control, data analysis, and graphical data presentation.

LabVIEW features interactive graphics, a state-of-the-art user interface, and a powerful graphical programming language. The LabVIEW Data Acquisition VI Library, a series of VIs for using LabVIEW with National Instruments DAQ hardware, is included with LabVIEW. The LabVIEW Data Acquisition VI Libraries are functionally equivalent to the NI-DAQ software.

LabWindows/CVI features interactive graphics, a state-of-the-art user interface, and uses the ANSI standard C programming language. The LabWindows/CVI Data Acquisition Library, a series of functions for using LabWindows/CVI with National Instruments DAQ hardware, is included with the NI-DAQ software kit. The LabWindows/CVI Data Acquisition libraries are functionally equivalent to the NI-DAQ software.

Using LabVIEW or LabWindows/CVI software will greatly diminish the development time for your data acquisition and control application.

DAQPad-1200 User Manual 1-2 © National Instruments Corporation

Chapter 1 Introduction

NI-DAQ Driver Software

The NI-DAQ driver software is included at no charge with all National Instruments DAQ hardware. NI-DAQ is not packaged with SCXI or accessory products, except for the SCXI-1200. NI-DAQ has an extensive library of functions that you can call from your application programming environment. These functions include routines for analog input (A/D conversion), buffered data acquisition (high-speed A/D conversion), analog output (D/A conversion), waveform generation (timed D/A conversion), digital I/O, counter/timer operations, SCXI, RTSI, self calibration, messaging, and acquiring data to extended memory.

NI-DAQ has both high-level DAQ I/O functions for maximum ease of use and low-level DAQ I/O functions for maximum flexibility and performance. Examples of high-level functions are streaming data to disk or acquiring a certain number of data points. An example of a low-level function is writing directly to registers on the DAQ device. NI-DAQ does not sacrifice the performance of National Instruments DAQ devices because it lets multiple devices operate at their peak performance—up to 500 kS/s on ISA computers and up to 1 MS/s on EISA computers.

NI-DAQ also internally addresses many of the complex issues between the computer and the DAQ hardware such as programming the PC interrupt and DMA controllers. NI-DAQ maintains a consistent software interface among its different versions so that you can change platforms with minimal modifications to your code. Figure 1-1 illustrates the relationship between NIDAQ and LabVIEW and LabWindows/CVI. You can see that the DAQ parts of LabVIEW and LabWindows/CVI are functionally equivalent to the NI-DAQ software.

Conventional

Programming

Environment

(PC, Macintosh, or

Sun SPARCstation)

DAQ or

SCXI Hardware

LabVIEW

(PC, Macintosh, or

Sun SPARCstation)

NI-DAQ

Driver Software

LabWindows/CVI

(PC or Sun

SPARCstation)

Personal

Computer or

Workstation

Figure 1-1. The Relationship between the Programming Environment,

NI-DAQ, and Your Hardware

Introduction Chapter 1

Register-Level Programming

The final option for programming any National Instruments DAQ hardware is to write registerlevel software. Writing register-level programming software can be very time-consuming and inefficient and is not recommended for most users.

Even if you are an experienced register-level programmer, always consider using NI-DAQ, LabVIEW, or LabWindows/CVI to program your National Instruments DAQ hardware. Using the NI-DAQ, LabVIEW, or LabWindows/CVI software is as easy and as flexible as registerlevel programming and can save you weeks of development time.

Optional Equipment

Contact National Instruments to order any of the following optional equipment:

BP-1 battery pack with a 110 or 230 VAC charger

0.5 or 1.0 m type NB1 ribbon cable CB-50 I/O connector block with a 1.0 m type NB1 cable CB-50 I/O connector block only SC-2071 general-purpose termination breadboard with a 0.5 or 1.0 m type NB1 ribbon cable 2 m parallel port cable

BP-1 Battery Pack

For total portability, you can power the DAQPad-1200 with the optional BP-1 battery pack. The BP-1 includes a 12 V, 3.2 Ahr battery packaged in an enclosure with the same dimensions as the DAQPad-1200. A fully charged BP-1 typically powers the DAQPad-1200 for 11 hours. A charger unit is included with the BP-1.

Adding an Enhanced Parallel Port (EPP)

If you have a slot available in your PC, you can add an EPP card to achieve higher DAQ rates. You can order one such card, the F/Port Enhanced Parallel Port Card, from Far Point Communications. You can use the card in a PC/AT 386, 486, or compatible computer.

If you have a PCMCIA type II slot available in your PC, you can add a PCMCIA to an EPP card to achieve higher DAQ rates. Two options are the SPP-100 from Quatech and the ExpressPort from FarPoint. Both cards comply with the PCMCIA PC Standard Specification 2.1.

DAQPad-1200 User Manual 1-4 © National Instruments Corporation

Chapter 1 Introduction

Custom Cables

The DAQPad-1200 front signal connector is a 50-pin male ribbon-cable header. The manufacturer part number of the header National Instruments uses is as follows:

• AMP Inc. (part number 1-103310-0) The mating connector for the DAQPad-1200 front signal connector is a 50-position polarized

ribbon-socket connector with strain relief. National Instruments uses a polarized or keyed connector to prevent inadvertent upside-down connection to the DAQPad-1200. Recommended manufacturer part numbers for this mating connector are as follows:

• Electronic Products Division/3M (part number 3425-7650)

• T&B/Ansley Corporation (part number 609-5041CE) Standard 50-conductor 28 AWG stranded ribbon cables that work with these connectors are as

follows:

• Electronic Products Division/3M (part number 3365/50)

• T&B/Ansley Corporation (part number 171-50) The DAQPad-1200 two rear connectors (the parallel and transparent parallel port connectors) are

the standard 25-pin D-Subminiature. The manufacturer part number of the connector National Instruments uses is as follows:

• AMP Inc. (part number 747846-5) You can use standard DB-25-style male connectors as mating connectors for the DAQPad-1200

rear connector.

Chapter 2 Installation and Configuration

This chapter describes how to install and software configure the DAQPad-1200.

Hardware Installation

There are five basic steps to installing the DAQPad-1200:

Note: If you are using the BP-1 battery pack, follow the installation instructions in your

BP-1 installation guide instead of steps 1 and 2. The maximum recommended discharge time for a fully-charged battery pack is 11 hours for an unloaded DAQPad-1200 and five hours for a DAQPad-1200 loaded at 350 mA from the +5 V I/O connector (pin 49).

1. Verify that the voltage on the wall-mount supply matches the voltage supplied in your area.

2. Connect one end of the wall-mount supply to an electrical outlet. Connect the other end to

the rear panel jack.

3. Connect the parallel port cable to the PC parallel port. Connect the other end of the cable to

port A on the DAQPad-1200, and screw in the mounting screws on the connectors to establish a firm connection.

4. If you are using the transparent parallel port, connect another parallel port cable to port B on

the DAQPad-1200. Connect the other end of the second parallel port cable to any standard parallel port device.

5. Push the front panel rocker switch to power on the DAQPad-1200. The power LED should

light up immediately.

If the power LED does not light up immediately, check the polarity of your power connections. The power input of the DAQPad-1200 is protected by a positive temperature coefficient (PTC) resistor. It takes approximately 20 s for the PTC resistor to reset after being tripped. Contact National Instruments if the power LED does not light up after correcting any faulty power connections.

The DAQPad-1200 unit is installed. You are now ready to install and configure your software.

Configuration

The DAQPad-1200 is completely software configurable; refer to your software manuals to install and configure the software.

If you are using NI-DAQ, refer to the NI-DAQ User Manual for PC Compatibles. The software installation and configuration instructions are in Chapter 1, Introduction to NI-DAQ. Find the installation and system configuration section for your operating system and follow the instructions given there.

Installation and Configuration Chapter 2

Parallel Port Configuration

During configuration, you must know the parallel port I/O address and interrupt channel. Common parallel port addresses are 0x378, 0x278, 0x3BC, 0x280, and 0x290. The DAQPad-1200 can use the parallel port hardware interrupts for interrupt-driven data acquisition. Interrupt levels 7 and 5 are commonly used for parallel ports. Refer to your parallel port reference manual for details about interrupt selection and address assignment. If you have problems configuring your parallel port, refer to Appendix B, Parallel Port Configuration Troubleshooting.

Analog I/O Configuration

On power up or after a software reset, the DAQPad-1200 is set to the following configuration:

• Referenced single-ended input mode

• ±5 V analog input range (bipolar)

• ±5 V analog output range (bipolar) Table 2-1 lists all the available analog I/O configurations for the DAQPad-1200 and shows the

configuration in reset condition.

Table 2-1. Analog I/O Settings

Parameter Configuration

Analog Output CH0 Polarity Bipolar–±5 V (reset condition); Unipolar–0 to 10 V Analog Output CH1 Polarity Bipolar–±5 V (reset condition); Unipolar–0 to 10 V Analog Input Polarity Bipolar–±5 V (reset condition); Unipolar–0 to 10 V Analog Input Mode Referenced single-ended (RSE) (reset condition)

Nonreferenced single-ended (NRSE) Differential (DIFF)

Both the analog input and analog output circuitries are software configurable.

Analog Output Polarity

The DAQPad-1200 has two channels of analog output voltage at the front panel I/O connector. You can configure each analog output channel for either unipolar or bipolar output. A unipolar configuration has a range of 0 to 10 V at the analog output. A bipolar configuration has a range of -5 V to +5 V at the analog output. In addition, you can select the coding scheme for each DAC as either two's complement or straight binary. If you select a bipolar range for a DAC, the two's complement coding is recommended. In this mode, data values written to the analog output channel range from F800 hex (-2,048 decimal) to 7FF hex (2,047 decimal). If you select a unipolar range for a DAC, the straight binary coding is recommended. In this mode, data values written to the analog output channel range from 0 to FFF hex (4,095 decimal).

Chapter 2 Installation and Configuration

Analog Input Polarity

You can select the analog input on the DAQPad-1200 for either a unipolar range (0 to 10 V) or a bipolar range (-5 to +5 V). In addition, you can select the coding scheme for analog input as either two's complement or straight binary. If you select a bipolar range, the two's complement coding is recommended. In this mode, -5 V input corresponds to F800 hex (-2,048 decimal) and +5 V corresponds to 7FF hex (2,047 decimal). If you select a unipolar mode, the straight binary coding is recommended. In this mode, 0 V input corresponds to 0 hex, and +10 V corresponds to FFF hex (4,095 decimal).

Analog Input Mode

The DAQPad-1200 has three different input modes–referenced single-ended (RSE) input, nonreferenced single-ended (NRSE) input, and differential (DIFF) input. The single-ended input configurations use eight channels. The DIFF input configuration uses four channels. Table 2-2 describes these configurations.

Table 2-2. Analog Input Modes for the DAQPad-1200

Analog Input

Description

Modes

RSE Referenced single-ended mode provides eight single-ended inputs with the

negative input of the instrumentation amplifier referenced to analog ground (reset condition).

NRSE Nonreferenced single-ended mode provides eight single-ended inputs with the

negative input of the instrumentation amplifier tied to AISENSE/AIGND and not connected to ground.

DIFF Differential mode provides four differential inputs with the positive (+) input of

the instrumentation amplifier tied to channels 0, 2, 4, or 6 and the negative (-) input tied to channels 1, 3, 5, or 7, respectively, thus choosing channel pairs (0, 1), (2, 3), (4, 5), or (6, 7).

While reading the following paragraphs, you may find it helpful to refer to the Analog Input Signal Connections section of Chapter 3, which contains diagrams showing the signal paths for the three configurations.

RSE Input (Eight Channels, Reset Condition) RSE input means that all input signals are referenced to a common ground point that is also tied

to the DAQPad-1200 analog input ground. The differential amplifier negative input is tied to analog ground. The RSE configuration is useful for measuring floating signal sources. With this input configuration, the DAQPad-1200 can monitor eight different analog input channels.

Installation and Configuration Chapter 2

Considerations for using the RSE configuration are discussed in Chapter 3, Signal Connections. Notice that in this mode, the return path of the signal is analog ground, at the connector through the AISENSE/AIGND pin.

NRSE Input (Eight Channels) NRSE input means that all input signals are referenced to the same common-mode voltage,

which floats with respect to the DAQPad-1200 analog ground. This common-mode voltage is subsequently subtracted by the input instrumentation amplifier. The NRSE configuration is useful for measuring ground-referenced signal sources.

Considerations for using the NRSE configuration are discussed in Chapter 3, Signal Connections. Notice that in this mode, the return path of the signal is through the negative terminal of the amplifier, at the connector through the AISENSE/AIGND pin.

DIFF Input (Four Channels) DIFF input means that each input signal has its own reference, and the difference between each

signal and its reference is measured. The signal and its reference are each assigned an input channel. With this input configuration, the DAQPad-1200 can monitor four differential analog input signals.

Considerations for using the DIFF configuration are discussed in Chapter 3, Signal Connections. Notice that the signal return path is through the negative terminal of the amplifier and through channel 1, 3, 5, or 7, depending on which channel pair you select.

Chapter 3 Signal Connections

This chapter describes the connection of a standard parallel port device to the rear panel transparent parallel port connector, the signal connections to the DAQPad-1200 unit via the DAQPad-1200 front I/O connector, and includes specifications and connection instructions for the DAQPad-1200 connector signals.

Transparent Parallel Port Connector

Note: You must power on the DAQPad-1200 to operate the standard parallel port device

which is connected to the transparent parallel port connector.

The DAQPad-1200 supports transparent parallel port connection to any standard parallel port device. The DAQPad-1200 does not support transparent parallel port connection to any device which supports the 1284 daisy-chain specification as defined by DISTEC, Inc.

When you power up the DAQPad-1200, the unit is in transparent mode. If you are using NI-DAQ, the DAQPad-1200 will be placed into transparent mode at the completion of every operation. In this mode, the DAQPad-1200 will transparently pass through all of the parallel port lines with minimal propagation delay. In normal applications, you operate either the DAQPad-1200 or the standard parallel port device connected to the transparent parallel port connector at any one time. For example, you cannot use a printer connected to the transparent parallel port connector and perform a DAQ operation at the same time. You can use the printer only after the DAQ operation has finished.

Front Connector

Figure 3-1 shows the pin assignments for the DAQPad-1200 front I/O connector. This connector is located on the front panel of the DAQPad-1200 unit.

Warning: Connections that exceed any of the maximum ratings of input or output signals

on the DAQPad-1200 may result in damage to the DAQPad-1200 unit and to the PC. This includes connecting any power signals to ground and vice versa. National Instruments is signal connections.

NOT liable for any damages resulting from any such

Signal Connections Chapter 3

ACH0 ACH2 ACH4 ACH6

AISENSE/AIGND

PC3

12 34 56 78

9 10

11 12 13 14 15 16 17 18 19 20

21 22 23 24

26 27 28 29 30 31 32 33 34

ACH1 ACH3 ACH5 ACH7 DAC0OUT

DAC1OUTAGND PA0DGND PA2PA1 PA4PA3 PA6PA5 PB0PA7 PB2PB1 PB4PB3 PB6PB5 PC0PB7 PC2PC1 PC4

35 36

PC5 PC6

37 38

PC7 EXTTRIG

EXTUPDATE*

OUTB0

CLKB1

+5 V

39 40 41 42 43 44 45 46 47 48 49 50

EXTCONV* GATB0 GATB1OUTB1 OUTB2 CLKB2GATB2 DGND

Figure 3-1. DAQPad-1200 Front I/O Connector Pin Assignments

+ 48 hidden pages

National Instruments DAQPAD-1200 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Limited Warranty

Copyright

Trademarks

Contents

Figures

Tables

About This Manual

Organization of This Manual

Conventions Used in This Manual

National Instruments Documentation

Related Documentation

Customer Communication

Chapter 1 Introduction

About the DAQPad-1200

What You Need to Get Started

Software Programming Choices

LabVIEW and LabWindows/CVI Application Software

NI-DAQ Driver Software

Register-Level Programming

Optional Equipment

BP-1 Battery Pack

Adding an Enhanced Parallel Port (EPP)

Custom Cables

Chapter 2 Installation and Configuration

Hardware Installation

Configuration

Parallel Port Configuration

Analog I/O Configuration

Table 2-1. Analog I/O Settings

Analog Output Polarity

Analog Input Polarity

Analog Input Mode

Table 2-2. Analog Input Modes for the DAQPad-1200

Chapter 3 Signal Connections

Transparent Parallel Port Connector

Front Connector

Figure 3-1. DAQPad-1200 Front I/O Connector Pin Assignments