This example shows how to use a falling edge digital trigger,
which occurs when a switch closes on an external source. The trigger is
connected to terminal
PFI0 on device
and starts acquiring sensor voltage data.
Create a data acquisition session and add channels.
s = daq.createSession('ni');
Add one voltage input channel from NI USB-6211 with device ID
Connect the switch to terminal
'PFI0' on NI USB-6211.
The trigger comes from the switch, which is an external source.
ans = Start Trigger is provided externally and will be received by 'Dev1' at terminal 'PFI0'. TriggerType: 'Digital' TriggerCondition: RisingEdge Source: 'External' Destination: 'Dev1/PFI0' Type: StartTrigger
TriggerCondition property to
c = s.Connections(1); c.TriggerCondition = 'FallingEdge';
Acquire data and store it in
dataIn. The session waits
for the trigger to occur, and starts acquiring data when the switch
dataIn = startForeground(s);