Chapter 4 Working with Signals
© National Instruments Corporation 4-3 Getting Started with LabVIEW SignalExpress
Importing a Signal from a File
You can import signals from standard file formats such as ASCII comma-
or tab-delimited files and LabVIEW measurement data files (.lvm). You
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 SignalExpress\Examples\Tutorial directory,
and double-click Step Response.txt. This step parses an ASCII file
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 imp ort 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 step response and press the <Enter> key to rename the output.
9. Drag the step response output of the Load from ASCII step to the
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.