National Instruments Measure Data Acquisition User Manual page 36

Choices for Hardware Digital
Trigger
Start acquisition on trigger
Acquire until trigger
scans after trigger
Timeout (seconds)
Select this option if you want to start your acquisition on
the rising edge of the PFI0/EXTTRIG/STARTTRIG
(depending on the board you are using) input on the
connector. Otherwise, Measure starts the acquisition
with a software trigger.
Select this option if you want to stop your acquisition on
the rising edge of the PFI1/EXTTRIG/STOPTRIG
(depending on the board you are using) signal on the
connector. Otherwise, the acquisition ends after Measure
acquires all the scans.
Specify the number of scans to acquire after the stop
trigger occurs.
Specify a timeout value in seconds. If you want Measure
to calculate a timeout value for you, enter -1. If you
specify an external scan clock and a timeout value of
-1, Measure configures a timeout of one second.
The Analog Input Mode applies to all the channels in your scan list.
Select Analog Input Configuration»Mode to open the Analog Input
Mode dialog box, shown in Figure 4-5.
Description