User`s guide

Retrieving Timing Information
InitialTriggerTime Records First Trigge r 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.TheexampleusestheMATLABda testr function to convert the
information i nto 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 toolb ox provides two ways to determine when a particular frame was
acquired:
• Bytheabsolutetimeoftheacquisition
• By the elapsed time relative to the execution of the trig ger
You can use the
getdata function to retrieve both types of timing inform ation.
Getting the Relative Acquisition Time
When you use the getdata function, you can optionally specify two return
values. On e return v alue co nta in s 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);
6-21