User`s guide

7 Working with Acquired Image Data
7-24
InitialTriggerTime Records First Trigger Execution
The trigger timing information is stored in MATLAB clock vector format. The following
example displays the time of the first trigger for the video input object vid. The example
uses the MATLAB datestr function to convert the information into a form that is more
convenient to view.
datestr(vid.InitialTriggerTime)
ans =
02-Mar-2007 13:00:24
Determining When a Frame Was Acquired
The toolbox provides two ways to determine when a particular frame was acquired:
• By the absolute time of the acquisition
• By the elapsed time relative to the execution of the trigger
You can use the getdata function to retrieve both types of timing information.
Getting the Relative Acquisition Time
When you use the getdata function, you can optionally specify two return values.
One return value contains the image data; the other return value contains a vector of
timestamps that measure, in seconds, the time when the frame was acquired relative to
the first trigger.
[data time] = getdata(vid);