How to clear/reset NI1433 buffer?

[aoslo]

I'm using NI PCIe-1433 to grab images from a line scan camera running on trigger mode.  The trigger is a 16 khz pulse train running continuously,  and is fed to NI-1433 via the SMB connector.  

I need to stich 500 lines together to form a picture. I set the acquisition window height to 500 in NI Max.  When I 'grab' in NI MAX, I can see all 500 lines okay.  Now, when a certain event happens (eg, the occurance of a pulse), I want to clear (reset) the frame grabber's buffer so that the next line grabbed becomes the first line in the acquisition window.  Can this be done through software?  I'm programming in VB using Visual Studio 2008, and the NI library CWIMAQ.dll.  Thanks very much.

[SSPTest]

aoslo,

There's no "line reset" input that I know of for the 1433. One way you could get around this fact is to monitor for some trigger input, and when you see it you can take the current line number and use that to perform some software processing to cut down your image to only include the information after you receive your trigger.

[aoslo]

SSPTest,

Is it possile to change the acquisition property of NI 1433 on the fly?  My thinking is this:  I'll set the linescan camera on freerun mode and start the acquisition.  As soon as my software dectects a pulse, I'll stop the acquisition, change the acquisition to "Triggered" mode, and the acqusition height to 500, and immediately start the acquisition again.

[BlueCheese]

The 1433 does have a notion of a variable-height linescan acquisition that might be a useful concept to experiment with. In this mode, typically an I/O line indicates when the the current image is "finished". Typically the I/O line stays high for the duration of the image and then when it goes low, the framegrabber stops the current image and starts acquiring the next one. It might be as simple as inverting your event pulse and using it as your VHA input.