National Instruments DAQCard-1200 Analog Input Mode

Chapter 2 Installation and Configuration

DAQCard-1200 User Manual 2-4 © National Instruments Corporation

Analog Input Mode

The DAQCard-1200 has three different input modes—referenced

single-ended (RSE), non-referenced single-ended (NRSE), and differential

(DIFF). Single-ended configuration provides eight input channels. DIFF

configuration provides four input channels. Table 2-2 describes these

configurations.

While reading the following paragraphs, you may find it helpful to refer to

the Analog Input Signal Connections section of Chapter 3, Signal

Connections, which contains diagrams showing the signal paths for the

three configurations. These three modes are software selectable.

RSE Input (Eight Channels, Default Setting)

RSE input means that all input signals are referenced to a common ground

point that is also tied to the DAQCard-1200 analog input ground. The RSE

configuration is useful for measuring floating signal sources. See the Types

of Signal Sources section of Chapter 3, Signal Connections , for more

information. With the RSE configuration, the DAQCard-1200 can monitor

eight different analog input channels.

Considerations for using the RSE configuration are discussed in Chapter3,

Signal Connections. Notice that in RSE mode, the return path of the

signalis through analog ground at the connector through th e

AISENSE/AIGND pin.

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

Analog

Input Modes Description

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

negative input of the instrumentation amplifier referenced to AISENSE/AIGND,

which is tied to ground through about 200 Ω resistance (default setting).

NRSE Non-referenced single-ended configuration 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 pairing channels (0, 1), (2,3), (4,5), (6,7).

Contents

Main Page Important Information Warranty Copyright Trademarks WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS Contents Chapter 4 Theory of Operation Page Tables About This Manual Organization of This Manual Conventions Used in This Manual National Instruments Documentation Related Documentation Introduction About the DAQCard-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 Unpacking Installation and Configuration Installation Configuration Analog Input Configuration Analog Input Polarity Analog Input Mode RSE Input (Eight Channels, Default Setting) NRSE Input (Eight Channels) DIFF Input (Four Channels) Analog Output Configuration Analog Output Polarity Digital I/O Configuration Counter Configuration Signal Connections I/O Connector Figure 3-1. DAQCard-1200 I/O Connector Pin Assignments Signal Connection Descriptions Analog Input Signal Connections + Types of Signal Sources Floating Signal Sources Ground-Referenced Signal Sources Input Configurations Differential Connection Considerations (DIFF Configuration) Differential Connections for Grounded Signal Sources Figure 3-3. Differential Input Connections for Grounded Signal Sources Differential Connections for Floating Signal Sources Figure 3-4. Differential Input Connections for Floating Sources Single-Ended Connection Considerations Single-Ended Connections for Floating Signal Sources (RSE Configuration) Single-Ended Connections for Grounded Signal Sources (NRSE Configuration) Common-Mode Signal Rejection Considerations Analog Output Signal Connections Digital I/O Signal Connections Page Port C Pin Connections Timing Specifications Mode 1 Input Timing Mode 1 Output Timing Mode 2 Bidirectional Timing Page DAQ and General-Purpose Timing Signal Connections DAQ Timing Connections Page Page Page General-Purpose Timing Signal Connections Page Page Figure 3-18. Frequency Measurement Application Chapter 3 Signal Connections DAQCard-1200 User Manual 3-30 National Instruments Corporation Figure 3-19. General-Purpose Timing Signals The GATE and OUT signals in Figure3-19 are referenced to the rising edge of the CLK signal. Power Connections National Instruments Corporation 4-1 DAQCard-1200 User Manual Theory of Operation This chapter explains the operation of each functional unit of the DAQCard-1200. Figure 4-1. DAQCard-1200 Block Diagram Functional Overview The block diagram in Figure 4-1 shows a functional overview of the DAQCard-1200. PC Card I/O Channel Interface Circuitry Timing Chapter 4 Theory of Operation Figure 4-3. Timing Circuitry DAQCard-1200 User Manual 4-4 National Instruments Corporation Analog Input Analog Input Circuitry Page Data Acquisition Timing Data Acquisition Operation Continuous Data Acquisition Interval Data Acquisition Data Acquisition Rates Page Analog Output Analog Output Circuitry Power-On State DAC Timing Digital I/O Calibration Calibration at Higher Gains Calibration Equipment Requirements Using the Calibration Function Page A Specifications Analog Input Input Characteristics Transfer Characteristics Amplifier Characteristics Dynamic Characteristics Stability Analog Output Output Characteristics Transfer Characteristics Page Timing I/O Digital Trigger Bus Interface Power Requirement Physical Page B Differences among the Lab-PC+, the DAQPad-1200, and the DAQCard-1200 Page C Power-Management Modes Page D PC Card Questions and Answers Configuration Operation Resources Page Page E Technical Support Resources NI Web Support Online Problem-Solving and Diagnostic Resources Software-Related Resources Worldwide Support Glossary Numbers/Symbols A B C D E F G Page Page V Index Numbers A B C D E F G I L M N O R S T U V W