External trigger to start recording of multiple frames

I would like to start recording a certain number of frames after an external trigger has been detected. The following code just records a single frame each time the external trigger is detected. I was expecting 600 frames in this example, because the parameter vid.FramesPerTrigger is set to 600.How can i detect N frames with a certain fps if triggered instead of just one single frame?

"start"
clear all

vid = videoinput('tisimaq_r2013_64', 1, 'Y800 (1280x1024)');
config = triggerinfo(vid);
s = vid.Source;

triggerconfig(vid, 'hardware', 'hardware', 'hardware');

vid.FramesPerTrigger = 600;
vid.TriggerRepeat = 0;

start(vid);
wait(vid, 10);
stop(vid);
[data,d] = getdata(vid, vid.FramesAvailable);
"end"

[Andrew Weitz]

Hi, did you ever figure out a solution? I am having the same problem with a TIS camera.