National Instruments 373873C-01 用户手册
Chapter 5
Logging Data
© National Instruments Corporation
5-5
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.
the signal based on the value of the edge of the signal on a positive
slope.
d.
Enter
1
in the Value control to begin recording when the signal
crosses 1 on a rising slope.
6.
Select Stop Conditions in the Category list in the Recording Options
View.
View.
7.
Click the Add button in the Logging stop conditions page to
customize a stop condition for your logging task.
customize a stop condition for your logging task.
a.
Select the Duration option in the Condition source control.
b.
Enter
5
in the Duration control to record the signal for 5 seconds
after the signal meets the start condition.
c.
Click the Run button, shown at left. LabVIEW SignalExpress
begins recording the signal when the signal crosses level 1 on a
rising slope and continues recording the signal for 5 seconds.
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.
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.
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.
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.
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.