National Instruments SCXI-1503 - page 52

Chapter 5 Using the SCXI-1503

© National Instruments Corporation 5-9 SCXI-1503 User Manual

Create Virtual Channel(s) DAQMX Create Virtual Channel.vi located on the

Functions»All Functions»NIMeasurements»DAQmx - Data

Acquisition subpalette—Use this VI to add virtual channels to

the task. Select the type of virtual channel based on the

measurement you plan to perform.

Adjust Timing Settings

(optional)

DAQmx Timing.vi (Sample Clock by default)—This VI is

optional if you created and configured the task using the DAQ

Assistant. Any timing settings modified with this VI are not

saved in the DAQ Assistant. They are only available for the

present session.

Configure Channels

(optional)

NI-DAQmx Channel Property Node, refer to the Using a

NI-DAQmx Channel Property Node in LabVIEW section for

more information. This step is optional if you created and fully

configured the channels using the DAQ Assistant. Any channel

modifications made with a channel property node are not saved

in the task in the DAQ Assistant. They are only available for the

present session.

Start Measurement DAQmx Start Task.vi

Read Measurement DAQmx Read.vi

Analyze Data Some examples of data analysis include filtering, scaling,

harmonic analysis, or level checking. Some data analysis tools

are located on the Functions»Signal Analysis subpalette and on

the Functions»All Functions»Analyze subpalette.

Display Data You can use graphical tools such as charts, gauges, and graphs

to display the data. Some display tools are located on the

Controls»All Controls»Numeric»Numeric Indicator

subpalette and Controls»All Controls»Graph subpalette.

Continue Sampling For continuous sampling, use a While Loop. If you are using

hardware timing, you also need to set the DAQmx Timing.vi

sample mode to Continuous Samples. To do this, right-click the

terminal of the DAQmx Timing.vi labeled sample mode and

click Create»Constant. Click the box that appears and select

Continuous Samples.

Table 5-5. Programming a Task in LabVIEW (Continued)

Flowchart Step VI or Program Step

Contents

Main Page Important Information Warranty Copyright Trademarks Patents Conventions Contents Chapter 1 About the SCXI-1503 Chapter 2 Connecting Signals Chapter 3 Configuring and Testing Chapter 4 Theory of Operation Chapter 5 Using the SCXI-1503 Page Tables About the SCXI-1503 What You Need to Get Started National Instruments Documentation Page Installing Application Software, NI-DAQ, and the E/M Series DAQ Device Installing the SCXI-1503 Module into the SCXI Chassis Installing the Terminal Block Configuring the SCXI System Software Page Connecting Signals Analog Input Signal Connections Ground-Referencing the Signals Connecting Resistive Devices to the SCXI-1503 4-Wire Configuration 2-Wire Configuration 3-Wire Resistive Sensor Configuration Lead-Resistance Compensation Using a 3-Wire Resistive Sensor and Two Matched Current Sources Figure 2-4. 3-Wire Configuration Using Matched Current Sources Front Connector Table 2-1. Front Signal Pin Assignments Page Rear Signal Connector Table 2-3 shows the SCXI-1503 module rear signal connector pin assignments. Table 2-3. Rear Signal Pin Assignments Rear Signal Connector Descriptions Page Configuring and Testing SCXI-1503 Software-Configurable Settings Common Software-Configurable Settings Gain/Input Range Input Coupling Configurable Settings in MAX NI-DAQmx Creating a Global Channel or Task Verifying the Signal Verifying the Signal in NI-DAQmx Using a Task or Global Channel Page Page Chapter 4 Theory of Operation Figure 4-1. Block Diagram of SCXI-1503 SCXI-1503 User Manual 4-2 ni.com Front Signal Connector Rear Signal Connector + Rear Signal Connector, SCXIbus Connector, and SCXIbus Interface Digital Control Circuitry Analog Circuitry Analog Input Channels Operation of the Current Sources Theory of Multiplexed Operation Measuring Temperature with Resistive Transducers RTDs RTD Measurement Errors The Relationship Between Resistance and Temperature in RTDs Page Page Page Thermistors Thermistor Measurement Circuits Resistance/Temperature Characteristic of Thermistors Page Using the SCXI-1503 Developing Your Application in NI-DAQmx Typical Program Flowchart Figure 5-1. Typical Program Flowchart for Voltage Measurement Channels General Discussion of Typical Flowchart Creating a Task Using DAQ Assistant or Programmatically Adjusting Timing and Triggering Configuring Channel Properties Page Page Acquiring, Analyzing, and Presenting Completing the Application Developing an Application Using LabVIEW Page Using a NI-DAQmx Channel Property Node in LabVIEW Specifying Channel Strings in NI-DAQmx Text Based ADEs LabWindows/CVI Measurement Studio (Visual Basic 6, .NET, and C#) Programmable NI-DAQmx Properties Calibration Internal/Self-Calibration External Calibration Page A Specifications Analog Input Input Characteristics Transfer Characteristics RTD Measurement Accuracy Amplifier Characteristics Dynamic Characteristics Filter Stability Excitation Power Requirements From SCXI Backplane Environmental Physical Maximum Working Voltage Safety Electromagnetic Compatibility CE Compliance Waste Electrical and Electronic Equipment (WEEE) B Removing the SCXI-1503 Removing the SCXI-1503 from MAX Removing the SCXI-1503 from a Chassis Figure B-1. Removing the SCXI-1503 C Common Questions Page Page Glossary Numbers/Symbols A B C D E G I J L M N O P R S T U V W Index Numerics A C D E F G I O P Q R S T V