Specify duration of acquisition
When working with the session-based interface, use the DurationInSeconds property to change the duration of an acquisition.
When the session contains digital or audio output channels, DurationInSeconds becomes a read only property.
If the output channels are analog, digital or audio, the value is determined by .
If the session contains only counter output channels with PulseGeneration measurement type, then DurationInSeconds represents the duration of the pulse train signal generation.
In a session with only input channels or counter output channels, you can enter a value in seconds for the length of the acquisition. Changing the duration changes the number of scans accordingly. By default, the DurationInSeconds is set to 1 second.
Create a session object, add an analog input channel, and change the duration:
s = daq.createSession('ni'); addAnalogInputChannel(s,'cDAQ1Mod1','ai0','voltage'); s.DurationInSeconds = 2
s = Data acquisition session using National Instruments hardware: Will run for 2 seconds (2000 scans) at 1000 scans/second. Operation starts immediately. Number of channels: 1 index Type Device Channel InputType Range Name ----- ---- --------- ------- --------- ---------------- ---- 1 ai cDAQ1Mod1 ai0 Diff -10 to +10 Volts