National Instruments 373873C-01 User Manual

LabVIEWTM SignalExpress

Getting Started with LabVIEW SignalExpress

Getting Started with LabVIEW SignalExpress

TM

August 2007
373873C-01

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Contents

About This Manual

Conventions ...................................................................................................................vii

Related Documentation..................................................................................................vii

Chapter 1
Introduction to LabVIEW SignalExpress

Chapter 2
Installing LabVIEW SignalExpress

LabVIEW SignalExpress LE.........................................................................................2-1

Minimum System Requirements ...................................................................................2-1

Installing LabVIEW SignalExpress...............................................................................2-2

Chapter 3
Working with Projects

Opening a Project...........................................................................................................3-1

Running a Project and Displaying Signals ....................................................................3-2

Configuring a Step.........................................................................................................3-4

Moving and Deleting Steps............................................................................................3-8

Handling Errors and Warnings ......................................................................................3-8

Chapter 4
Working with Signals

Graphing Signals............................................................................................................4-1

Importing a Signal from a File.......................................................................................4-3

Aligning and Comparing Signals...................................................................................4-4

Signal Types in LabVIEW SignalExpress.....................................................................4-6

Exporting and Printing Signals ......................................................................................4-6

Saving Signals to File......................................................................................4-7

Exporting Signals to Microsoft Excel .............................................................4-7

Printing Signals ...............................................................................................4-7

Creating Reports in LabVIEW SignalExpress ................................................4-7

© National Instruments Corporation v Getting Started with LabVIEW SignalExpress

Contents

Chapter 5
Logging Data

Recording a Signal ........................................................................................................ 5-1

Viewing a Logged Signal .............................................................................................. 5-2

Logging Signals with Predefined Start and Stop Conditions ........................................ 5-3

Analyzing Logged Signals ............................................................................................5-5

Advanced Playback .......................................................................................................5-6

Chapter 6
Performing Sweep Measurements

Defining Sweep Ranges and Outputs............................................................................6-1

Plotting Sweep Results.................................................................................................. 6-4

Running Multidimensional Sweeps...............................................................................6-5

Chapter 7
Extending LabVIEW SignalExpress Projects with LabVIEW

Importing LabVIEW VIs into LabVIEW SignalExpress as Steps................................7-1

Converting LabVIEW SignalExpress Projects to LabVIEW Block Diagrams............. 7-4

Chapter 8
Where to Go from Here

LabVIEW SignalExpress Sample Projects.................................................................... 8-1

Using Hardware with LabVIEW SignalExpress...........................................................8-1

Web Resources ..............................................................................................................8-1

Appendix A
Technical Support and Professional Services

Getting Started with LabVIEW SignalExpress vi ni.com

About This Manual

Use this manual to familiarize yourself with LabVIEW SignalExpress
interactive measurements and the basic LabVIEW SignalExpress features
that you use to acquire and analyze signals.

This manual contains exercises that help you begin working with
LabVIEW SignalExpress. These exercises teach you how to run projects,
configure steps, work with signals, configure sweep measurements, log
data, and extend LabVIEW SignalExpress with LabVIEW graphical
programming.

Conventions

The following conventions appear in this manual:

» The » symbol leads you through nested menu items and dialog box options

to a final action. The sequence File»Page Setup»Options directs you to
pull down the File menu, select the Page Setup item, and select Options
from the last dialog box.

This icon denotes a note, which alerts you to important information.

bold Bold text denotes items that you must select or click in the software, such

as menu items and dialog box options. Bold text also denotes input and
output names, parameter names, dialog boxes, sections of dialog boxes, and
menu names.

italic Italic text denotes variables, emphasis, a cross-reference, or an introduction

to a key concept. Italic text also denotes text that is a placeholder for a word
or value that you must supply.

monospace Text in this font denotes text or characters that you should enter from the

keyboard. This font is also used for the proper names of disk drives, paths,
directories, programs, subprograms, subroutines, device names, functions,
operations, variables, filenames, and extensions.

Related Documentation

Refer to the LabVIEW SignalExpress Help, available by selecting Help»
LabVIEW SignalExpress Help, for more information as you read this

manual.

© National Instruments Corporation vii Getting Started with LabVIEW SignalExpress

Introduction to LabVIEW
SignalExpress

National Instruments provides innovative solutions for scientists
and engineers to build automated measurement systems based on
industry-standard computers and platforms. National Instruments develops
robust, industry-leading programming environments for automating
measurement systems, such as LabVIEW for graphical development,
LabWindows
for Microsoft Visual Studio programming. You can use these programming
tools with National Instruments measurement hardware and interfaces to
traditional instruments to build custom, advanced virtual instrumentation
systems.

LabVIEW SignalExpress optimizes virtual instrumentation for design
engineers by offering instant interactive measurements that require no
programming. You can use LabVIEW SignalExpress interactively to
acquire, generate, analyze, compare, import, and log signals. You can
compare design data with measurement data in one step. LabVIEW
SignalExpress extends the ease of use and performance of virtual
instrumentation to those who must acquire or analyze signals without
programming applications. You also can extend the functionality of
LabVIEW SignalExpress by importing a custom virtual instrument (VI)
created in the LabVIEW Development System or by converting a
LabVIEW SignalExpress project to a LabVIEW block diagram so you can
continue development in LabVIEW. Refer to Chapter 7, Extending

LabVIEW SignalExpress Projects with LabVIEW, for more information.

™

/CVI™ for ANSI C programming, and Measurement Studio

1

© National Instruments Corporation 1-1 Getting Started with LabVIEW SignalExpress

Installing LabVIEW
SignalExpress

You can use the LabVIEW SignalExpress CD to install LabVIEW
SignalExpress and complete the exercises in this manual.

LabVIEW SignalExpress LE

LabVIEW SignalExpress LE gives you a 30-day trial of the Full version of
LabVIEW SignalExpress. After that period, you must activate your version
of LabVIEW SignalExpress LE or purchase the Full version. If you activate
your version of LabVIEW SignalExpress LE before your 30-day trial of the
full version is complete, the full features are still available for the remainder
of your 30-day trial. You can use LabVIEW SignalExpress LE to complete
simple data acquisition and logging functions.

If you do not register your version of LabVIEW SignalExpress LE after
30 days, LabVIEW SignalExpress LE runs with the following limitations:

• You can no longer save projects, so you cannot convert projects into
LabVIEW block diagrams.

• You can run projects for only 10 minutes per session.

2

Refer to the National Instruments Web site at
purchase the full version of LabVIEW SignalExpress.

ni.com/signalexpress to

Minimum System Requirements

LabVIEW SignalExpress requires a minimum of 256 MB of RAM and a
Pentium III or later or Celeron 866 MHz or equivalent processor, but
National Instruments recommends 512 MB of RAM and a Pentium 4/M or
equivalent processor.

© National Instruments Corporation 2-1 Getting Started with LabVIEW SignalExpress

Chapter 2 Installing LabVIEW SignalExpress

Installing LabVIEW SignalExpress

Complete the following steps to install LabVIEW SignalExpress on
Windows Vista/XP/2000/NT.

Note If you want to convert LabVIEW SignalExpress projects to LabVIEW block

diagrams, you must install LabVIEW 7.1 or later before you install LabVIEW
SignalExpress.

1. Disable any automatic virus detection programs before you install.
Some virus detection programs interfere with the installation program.

2. Log on as an administrator or as a user with administrator privileges.

3. Insert the LabVIEW SignalExpress Development or Evaluation CD
and follow the instructions that appear on the screen.

By default, LabVIEW SignalExpress installs in the

National Instruments\SignalExpress

4. After installation, check the hard disk for viruses and enable any virus
detection programs you disabled.

The example projects you use with this manual are located in

SignalExpress\Examples\Tutorial. The solutions for each exercise

are located in

SignalExpress\Examples\Tutorial\Solutions.

Program Files\

directory.

If you use LabVIEW SignalExpress with National Instruments data
acquisition or modular instrumentation hardware, you must install
NI-DAQmx 8.5 or later, NI-SCOPE 2.7 or later, NI-FGEN 2.2 or later, or
NI-DMM 2.4.2. LabVIEW SignalExpress includes a National Instruments
Driver CD that includes these drivers.

Getting Started with LabVIEW SignalExpress 2-2 ni.com

Working with Projects

You can use LabVIEW SignalExpress to define measurement procedures
by adding and configuring steps in an interactive measurement
environment. A step is a configurable function that acquires, generates,
analyzes, loads, or stores signals. Most steps process input signals and
produce output signals. You can configure the operation of a step by
specifying values in a configuration view. A saved sequence of configured
steps is a LabVIEW SignalExpress project.

This chapter teaches you how to load and run existing projects and how to
configure steps in these projects.

Opening a Project

Complete the following steps to load a sample project in LabVIEW
SignalExpress.

1. Launch LabVIEW SignalExpress.
Notice that LabVIEW SignalExpress is split into three main views: the

Project View on the left, the Data View in the middle, and the help on
the right. Within the Data View, you should see the Data View tab, the
Logging Options tab, and the Project Documentation tab.

2. If LabVIEW SignalExpress does not open in the factory-default
configuration, select View»Data View to display the Data View.

3. Select File»Open Project, navigate to the

Examples\Tutorial
Project.seproj LabVIEW SignalExpress project.

4. Examine the window that appears, as shown in Figure 3-1 with the
help hidden, to learn about different components of LabVIEW
SignalExpress.

3

SignalExpress\

directory, and double-click the First

© National Instruments Corporation 3-1 Getting Started with LabVIEW SignalExpress

Chapter 3 Working with Projects

1

2

3

4

5

6

5

7

1 Execution control buttons
2 Work Area pull-down menu
3Step

9

4 Input
5 Output
6Project View

8

7 Logged Data window
8 Data View
9 Record button

Figure 3-1. First Project.seproj

The left pane is the Project View, which presents the order of
operations, or steps, for the project. The right pane is the Data View,
which displays the signal that the project generates and analyzes.

Running a Project and Displaying Signals

LabVIEW SignalExpress has two execution modes—Run and Run Once.
When you click the Run button, LabVIEW SignalExpress executes all
steps in the project continuously until you click the Stop button. The Stop
button appears in place of the Run button as a project runs. While the steps
in the project execute, the Data View updates continuously. While the
project runs, you can change the measurement configurations and view the

Getting Started with LabVIEW SignalExpress 3-2 ni.com

Chapter 3 Working with Projects

results immediately. If you modify the configuration of steps while a
project runs, LabVIEW SignalExpress gives you direct, immediate
feedback on the changes you make. When you click the Run Once button,
LabVIEW SignalExpress executes all steps in the project one time.

Complete the following steps to run the sample project and display signals.

1. Click the Run button, shown at left, to execute all steps in the project
continuously.

The project loads a signal from a text file and performs two operations
on the signal—an amplitude and levels measurement and a distortion
measurement. The Amplitude and Levels step and the Distortion step
perform these measurements, respectively. When you run a project,
steps analyze input signals and generate new output signals as a result
of the analysis. In this project, the Load from ASCII step loads a
distorted sine wave, the Amplitude and Levels step and the Distortion
step analyze the sine wave, and both steps return new outputs. In the
Project View, LabVIEW SignalExpress indicates inputs with red
arrows and outputs with blue arrows.

The graph in the Data View still contains the loaded signal, which is a
time-domain signal. Graphs display time-domain, frequency-domain,
or x-y signals.

2. Click the exported spectrum output signal of the Distortion step in the
Project View and drag it to the Data View to display the signal.

LabVIEW SignalExpress creates a new graph in the Data View.
LabVIEW SignalExpress does not display the exported spectrum
signal on the same graph as the time-domain signal because the
exported spectrum signal is a frequency-domain signal. LabVIEW
SignalExpress automatically recognizes different types of signals and
renders them in the appropriate displays.

3. Select Help»LabVIEW SignalExpress Help, click the Search tab,
and enter

"signal types" to refer to the LabVIEW SignalExpress

Help for more information about signal types. The help provides

information about using LabVIEW SignalExpress functionality such
as projects, steps, and signals.

4. Click the dc output of the Amplitude and Levels step and drag it to the
Data View to display the measurement.

LabVIEW SignalExpress creates a table to display the scalar
measurement from the dc output.

© National Instruments Corporation 3-3 Getting Started with LabVIEW SignalExpress

Chapter 3 Working with Projects

5. Drag the rms output to the table to display the scalar RMS

measurement.
LabVIEW SignalExpress creates a new row in the table to display the

second measurement. The project should appear as shown in
Figure 3-2.

Figure 3-2. Outputs of First Project.seproj

Configuring a Step

A step is a configurable function that acquires, generates, analyzes, loads,
or stores signals. Steps process input signals and produce output signals.
You can configure the operation of a step in SignalExpress by specifying
values in the Step Setup dialog box, or configuration view, for that step.
While a project runs, you can modify the configuration of steps to view
immediate feedback on the changes and adjust the measurements until you
achieve the results you need.

Getting Started with LabVIEW SignalExpress 3-4 ni.com

Chapter 3 Working with Projects

Complete the following steps to configure the Distortion step and the
Amplitude and Levels step.

1. Double-click the Distortion step in the Project View. The Step Setup
dialog box for the Distortion step appears, as shown in Figure 3-3.

Figure 3-3. Distortion Step Setup Dialog Box

On the Configuration tab, the settings indicate that the Distortion step
receives a time-domain waveform signal as an input, performs a power
spectrum on the signal to convert it to the frequency domain, and
computes the total harmonic distortion (THD) and fundamental
frequency of the signal. The step generates three measurements as
outputs—the spectrum, the THD, and the fundamental frequency of
the original time-domain waveform input.

2. If the context help does not appear on the right side of the screen, click
the Show Help button, shown at left, to display complete reference
information about the step. The upper half of the context help displays
information about the step, and the lower half of the context help
displays information about an object when you move the cursor over
the object.

© National Instruments Corporation 3-5 Getting Started with LabVIEW SignalExpress

Chapter 3 Working with Projects

3. On the Configuration tab, select Fundamental Tone from the
Export signals (THD) pull-down menu.

The operation of the step changes from displaying the
frequency-domain spectrum of the entire input signal to displaying
only the frequency spectrum of the fundamental tone of the input
signal. The graphed signals in the top half of the Step Setup dialog box
update to reflect the change you made.

4. Select Harmonics Only from the Export signals (THD) pull-down
menu.

The step changes to export only the spectrum of the harmonic signals
from the input signal. Both the output signal of the Distortion step and
the graph on the Data View update to reflect the change you made.

5. Click the Amplitude and Levels step in the Project View.
The Step Setup dialog box changes from displaying the configuration

of the Distortion step to displaying the configuration of the Amplitude
and Levels step.

Getting Started with LabVIEW SignalExpress 3-6 ni.com

Chapter 3 Working with Projects

6. Click the Input/Output tab to display the list of possible inputs and

outputs for this step, as shown in Figure 3-4.

Figure 3-4. Amplitude and Levels Step Setup Dialog Box

7. Place checkmarks in the Export +peak value, Export -peak value,
and Export peak-peak value checkboxes to configure the Amplitude
and Levels step to return three additional measurements.

Three additional outputs appear in the Project View.

8. Click the Data View tab to display the Data View.

9. Drag the three new outputs from the Project View to the table to
display the scalar measurements.

10. Click the Stop button, shown at left, to stop the project.
When you click the Stop button, the project stops running after

completing the current cycle of operations, or the current iteration.
Click the down arrow on the Stop button and click the Abort button to
completely stop the project without finishing the current iteration.

© National Instruments Corporation 3-7 Getting Started with LabVIEW SignalExpress

Chapter 3 Working with Projects

11. Select File»Save Project As and save the project as My First

Project.seproj in the SignalExpress\Examples\Tutorial

directory.

12. Select File»Close Project to close the project.

Moving and Deleting Steps

The steps in SignalExpress projects depend on input data, which means
steps can operate only on signals exported from previous steps in the
Project View. When you click the Input signal pull-down menu on the
Input tab of the Step Setup dialog box of a step, the menu displays only
compatible signals exported from a previous step. When the output of a
step becomes the input of another step, the steps become dependent on each
other, and the two steps execute sequentially at the same rate. The first step
generates an output signal that the second step must receive as an input
before the step can execute.

You can move a step within a project by dragging it up or down in the
Project View. You can delete a step by right-clicking it in the Project View
and selecting Delete from the shortcut menu. However, when you move or
delete a step, the status of signals in the project changes. For example, if
you delete a step that generates output signals, the operation of the project
breaks if any of the deleted output signals are inputs for other steps, and an
error indicator appears in the Project View. You also can cut, copy, and
paste steps within a project by pressing the <Ctrl-X>, <Ctrl-C>, and
<Ctrl-V> keys, respectively, or by right-clicking a step in the Project View
and selecting Cut, Copy, Paste Before Selected Step, or Paste After
Selected Step from the shortcut menu.

Handling Errors and Warnings

If an error occurs while a project runs, an error indicator, shown at left,
appears in the Project View on the step that encountered the error.
Double-click the step with the error to display an error description across
the bottom of the Step Setup dialog box. Click the Details button to the
right of the error description to display the full error description.

SignalExpress logs all errors and warnings in the Event Log while a project
runs. To display the Event Log, select

Log

tab in the Data View area. Refer to the

more information about errors and warnings by selecting

SignalExpress Help

Getting Started with LabVIEW SignalExpress 3-8 ni.com

, clicking the

View»Event Log

LabVIEW SignalExpress Help

Search

tab, and entering

and click the

Help»LabVIEW

errors

Event

.

for

Working with Signals

You can use LabVIEW SignalExpress to generate and analyze signals to
evaluate designs without programming. This chapter teaches you how to
work with signals in LabVIEW SignalExpress, including how to plot
signals on graphs, import signals from a file, interactively align and
compare two signals, and save signals to a file.

Graphing Signals

Complete the following steps to plot signals in a sample project and
examine the signals visually using cursors.

1. Select File»Open Project, navigate to the

Examples\Tutorial
Signals.seproj. This project configures the Create Signal step

to create a square wave signal and the Filter step to perform a lowpass
Butterworth filter.

2. Drag the step signal output of the Create Signal step to the Data View.

3. Drag the filtered step output of the Filter step to the Data View.
You can plot signals of the same signal type on the same graph. Both

the step signal and the filtered step signals are time-domain signals,
so they appear on the same graph. If you want to plot signals of
different types, drag the signals to the same graph and LabVIEW
SignalExpress creates a new graph.

4. Click the Add Display button, shown at left, on the toolbar to create a
new graph.

5. Drag the filtered step output of the Filter step to the new graph.

4

SignalExpress\

directory, and double-click

© National Instruments Corporation 4-1 Getting Started with LabVIEW SignalExpress

Chapter 4 Working with Signals

6. Right-click the new graph and select Visible Items»Cursors from the

shortcut menu to display two interactive cursors, as shown in
Figure 4-1.

Figure 4-1. Signals.seproj

As you drag the cursors, LabVIEW SignalExpress displays the x and
y values of the cursors in the cursor table at the bottom of the Data
View.

7. Select File»Save Project As and save the project as

My Signals.seproj in the SignalExpress\Examples\
Tutorial

Getting Started with LabVIEW SignalExpress 4-2 ni.com

directory.

Importing a Signal from a File

You can import signals from standard file formats such as ASCII comma­or tab-delimited files and LabVIEW measurement data files (
also can import signals from simulated results of EDA tools such as SPICE
simulators.

Complete the following steps to import a signal from a file.

1. Right-click the Project View and select Load/Save Signals»Analog
Signals»Load from ASCII from the shortcut menu.

2. Click the browse button, shown at left, in the Step Setup dialog box,
navigate to the
and double-click
and displays the signals in the file.

In the File preview section, column 1 shows the time stamp data, and
column 2 shows the actual voltage values of the signal.

3. Click the Import Signals tab to display the available signals in the file.

4. Place a checkmark in the Column 2 checkbox to import that signal,
and remove the checkmark from the Column 1 checkbox.

The Step Setup dialog box displays a preview of the signal in the
Imported Signal section.

5. Select Column 1 from the Input X values pull-down menu to set the
x-axis data of the waveform to the appropriate values.

6. Open the Data View.

7. Right-click the Column 2 output in the Project View and select
Rename from the shortcut menu.

8. Enter

9. Drag the step response output of the Load from ASCII step to the

step response and press the <Enter> key to rename the output.

lower graph in the Data View.
The filtered step signal resembles the rising edge of the step response

output, as shown in Figure 4-2.

SignalExpress\Examples\Tutorial directory,

Step Response.txt. This step parses an ASCII file

Chapter 4 Working with Signals

.lvm). You

© National Instruments Corporation 4-3 Getting Started with LabVIEW SignalExpress

Chapter 4 Working with Signals

Figure 4-2. Signals of Signals.seproj

10. Select File»Save Project to save the project.

Aligning and Comparing Signals

Although the filtered step signal and the step response output both show
an overshoot in the rising edge, assessing the similarity between the two
is difficult because the signals come from different sources and vary in
amplitude and timing. However, you can use the Interactive Alignment step
to align and compare two signals, so you can choose which type of
information you want to export from the operation to use in the project.

Complete the following steps to align two signals in the

My Signals.seproj project.

1. Right-click the step response output and select Send To»
Processing»Analog Signals»Interactive Alignment from the

shortcut menu to pass the step response signal from the Load from
ASCII step to the Interactive Alignment step.

Getting Started with LabVIEW SignalExpress 4-4 ni.com

Chapter 4 Working with Signals

The step selects the two most recent signals from the project to use as
inputs and displays the signals on the graph of the Step Setup dialog
box, as shown in Figure 4-3.

Figure 4-3. Interactive Alignment Step Setup Dialog Box

When you add a step to a project, LabVIEW SignalExpress selects
input signals based on the signal types the step can accept. For
example, the Interactive Alignment step can operate only on
time-domain waveform signals. Therefore, the step selects as inputs
the last two time-domain signals created in the project. To change the
input signals for a step, select different signals from the pull-down
menu of compatible signals in the Input/Output tab of the Step Setup
dialog box.

2. Click the red signal in the Input Signals graph and drag it to another

point within the graph.
You can drag, expand, and contract signals on the graph.

3. Try to align the rising edges of the two signals by dragging a signal
within the graph. Click a signal to set an anchor point and press and
hold the <Alt> key to stretch the signal around that anchor point in the
x and y directions.

© National Instruments Corporation 4-5 Getting Started with LabVIEW SignalExpress

Chapter 4 Working with Signals

On the Alignment tab of the Step Setup dialog box, the step computes
and displays the x and y gain and offset values you need to achieve
alignment specifications as you drag the signals.

4. Select Auto - Step from the Mode pull-down menu to align the

signals. LabVIEW SignalExpress bases this alignment mode on
built-in algorithms.

The lower graph in the Step Setup dialog box displays the difference
between the two signals.

5. On the Input/Output tab, place a checkmark in the Export aligned
signals checkbox to add the signals to the outputs of the step.

6. Select the Data View tab to open the Data View.

7. Click the Add Display button, shown at left, to add a third graph.

8. Drag the aligned reference and aligned test outputs of the Interactive
Alignment step to the new graph to view the aligned signals.

9. Select File»Save Project to save the project.

Signal Types in LabVIEW SignalExpress

Some steps, such as the Arithmetic step, can operate on multiple signal
types. For example, you can use the Arithmetic step to operate on
time-domain or frequency-domain waveforms. The Arithmetic step
changes behavior based on the type of input signals you select for the
step. For example, if you add two time-domain signals, LabVIEW
SignalExpress adds only their amplitudes. However, if you add two
frequency-domain phase signals, LabVIEW SignalExpress adds the
appropriate phase shift.

Refer to the LabVIEW SignalExpress Help for more information by
selecting Help»LabVIEW SignalExpress Help, clicking the Search tab,
and entering

"signal types".

Exporting and Printing Signals

You can use LabVIEW SignalExpress to document signals or continue
analysis in another software application. This section teaches you how to
export signals, including sending signals to an ASCII file, sending data to
Microsoft Excel, printing signals, and using the built-in documentation
feature to document the LabVIEW SignalExpress project.

Getting Started with LabVIEW SignalExpress 4-6 ni.com

Saving Signals to File

Complete the following steps to save a signal to a file.

1. Click the Add Step button and select Load/Save Signals»Analog

2. Click the Signals tab in the Step Setup dialog box and select filtered

3. On the File Settings tab, save the file to

4. Select Overwrite from the If file already exists pull-down menu.

5. Select Generic ASCII from the Export file type pull-down menu.

6. Click the Close button to close the Step Setup dialog box.

7. Click the Run button to run the project and save the resulting signal to

8. Select File»Save Project to save the project.

9. Select File»Close Project to close the project.

Chapter 4 Working with Signals

Signals»Save to ASCII/LVM.

step from the Input Data pull-down menu.

SignalExpress\

Examples\Tutorial\filtered signal.txt

path control.

You can use a Load/Save Signals step to save data to a file every time
the project runs.

the specified ASCII file.

in the Export file

Exporting Signals to Microsoft Excel

To export signal data to Microsoft Excel, launch Excel and drag the output
signal of a step in LabVIEW SignalExpress to an Excel spreadsheet.

Printing Signals

To print an image of a graph, open the Data View and select File»Print»
Print Data View.

Creating Reports in LabVIEW SignalExpress

Select

View»Project Documentation

View. You can describe your project using text and drag and drop step
outputs into your documentation. When you drag and drop a step output into
the Project Documentation View, the value in the Project Documentation
View automatically updates to match the current value of the step output.

To print your documentation, open the Project Documentation View and
select File»Print»Print Documentation. To export your documentation to
HTML, open the Project Documentation View and select File»Export»
Export Documentation to HTML.

© National Instruments Corporation 4-7 Getting Started with LabVIEW SignalExpress

to display the Project Documentation

Logging Data

You can use LabVIEW SignalExpress to record and analyze
measurements. You can record any time-domain, double, U32, or Boolean
step output. You also can analyze and process logged data by playing it
through analysis steps.

This chapter teaches you how to record data using the integrated data
logging features in LabVIEW SignalExpress. You learn how to record a
specified signal, play back that signal, and analyze the signal using analysis
steps. You also learn how to use the Recording Options View to log signals
based on specified start or stop conditions.

Recording a Signal

You can use the Record button to configure a data logging process.

Complete the following steps to specify a signal to record and to record the
signal.

1. Select File»Open Project, navigate to the

Examples\Tutorial
Logging.seproj.

This project uses the Create Signal step to generate a signal based on a
formula.

2. Click the Record button, shown at left, to open the Logging Signals
Selection dialog box.

The Logging Signals Selection dialog box displays the signals in the
project available for recording. You can select one signal or multiple
signals to record. You also can specify a name and description for
the log.

3. Place a checkmark in the signal checkbox to record the formula signal
generated in the Create Signal step.

4. Click the OK button to close the Logging Signals Selection dialog
box and begin recording the signal. The logging operation continues
until you click the Stop button.

5

SignalExpress\

directory, and double-click

© National Instruments Corporation 5-1 Getting Started with LabVIEW SignalExpress

Chapter 5 Logging Data

5. Click the Stop button, shown at left, to stop logging the signal.
The logged data appears in the Logged Data window, as shown in

Figure 5-1.

Figure 5-1. Logged Data Window

By default, LabVIEW SignalExpress names the logged data according
to the date and time you recorded the data. LabVIEW SignalExpress
saves logged data in the
in the Options dialog box.

6. Select Tools»Options and select the Logging option to specify the
directory for LabVIEW SignalExpress to save the logged data and to
customize various preferences for logged data.

7. Click the OK button to close the Options dialog box.

8. Select File»Save Project to save the project.

.tdms file format in the directory you specify

Viewing a Logged Signal

Complete the following steps to view the logged data.

1. If the Data View is not visible, select View»Data View to display the
Data View.

2. The Logged Data window displays a list of all logged data in the
current project. Select the data log you just recorded from the Logged
Data window and drag it into the Data View. The Data View displays
the logged data and a preview graph, as shown in Figure 5-2. The
signal displayed in the Data View may differ from the signal displayed
in Figure 5-2, depending on how long you record the signal.

Getting Started with LabVIEW SignalExpress 5-2 ni.com

Figure 5-2. Logging.seproj

Chapter 5 Logging Data

The preview graph provides a method for zooming and panning
through data in the Data View. The preview graph appears by default
when viewing logged data. When viewing live or non-logged data,
right-click the Data View and select Visible Items»Preview to display
the preview graph.

3. Click the Zoom In button next to the preview graph to zoom in on the

logged signal. The cursors on the preview graph show the subset of
data currently displayed on the preview graph. Use the scroll bar
beneath the preview graph to scroll through the data. Click and drag the
cursors on the preview graph to increase or decrease the subset of data
you are viewing.

Logging Signals with Predefined Start and Stop Conditions

You can configure start and stop conditions that the signals must meet
before LabVIEW SignalExpress records or stops recording the signals.
Complete the following steps to log data based on start and stop conditions.

1. If the Recording Options tab is not visible, select View»Recording
Options to open the Recording Options View.

© National Instruments Corporation 5-3 Getting Started with LabVIEW SignalExpress

Chapter 5 Logging Data

2. Select Signal Selection in the Category list in the Recording Options

View.

3. Place a checkmark next to the signal in the Record column, as shown

in Figure 5-3.

Figure 5-3. Signal Selection

The Record button changes to the Record While Running button,
shown at left. Ensure the Record While Running button is pressed.
When the Record While Running button is pressed, LabVIEW
SignalExpress records the selected signal when you click the Run or
Run Once button.

4. Select Start Conditions in the Category list in the Recording Options

View.

5. Click the Add button in the Logging start conditions page to

customize a start condition for your logging task.
a. Select the Signal option in the Condition source control to

specify for LabVIEW SignalExpress to begin recording when the
input signal meets the specified condition.

b. Select signal in the Signal control.

Getting Started with LabVIEW SignalExpress 5-4 ni.com

Chapter 5 Logging Data

c. Select Rising slope in the Condition control to begin recording

the signal based on the value of the edge of the signal on a positive
slope.

d. Enter

6. Select Stop Conditions in the Category list in the Recording Options
View.

7. Click the Add button in the Logging stop conditions page to
customize a stop condition for your logging task.

a. Select the Duration option in the Condition source control.
b. Enter

c. Click the Run button, shown at left. LabVIEW SignalExpress

1 in the Value control to begin recording when the signal

crosses 1 on a rising slope.

5 in the Duration control to record the signal for 5 seconds

after the signal meets the start condition.

begins recording the signal when the signal crosses level 1 on a
rising slope and continues recording the signal for 5 seconds.

The Recording indicator on the bottom of the Recording Options
View will turn on when the signal meets the start condition and
logging is in progress. The Disk information indicator displays
the available hard disk space on the computer for the log.

Analyzing Logged Signals

After you log a signal, you can play back the logged data or run the logged
signal through analysis steps, just as you can with live data. Complete the
following steps to analyze a logged signal.

1. Navigate to the Work Area pull-down menu on the top left of the
LabVIEW SignalExpress window, as shown in Figure 5-4. Click the
down arrow and select Playback to switch to the Playback work area.

Figure 5-4. Work Area pull-down menu

Use work areas to perform multiple LabVIEW SignalExpress
operations from within the same project. You can acquire data, process
signals, record data, and perform measurements on logged data
without opening a new project. When you save your project,
LabVIEW SignalExpress saves every work area within the project in
the same project file.

© National Instruments Corporation 5-5 Getting Started with LabVIEW SignalExpress