Imaq 1394 Software Trigger

[Thor]

Greetings!

In my application, I will be applying an electrical current to a filament, and detecting it with a PixeLink A741 camera...

Lately, I've been using astronomy and SLR cameras, so I've just been setting the shutter time for 1sec, trigger the camera, apply the pulse, etc...

(This was not automated... a person got to do all this and then download the picture off the SD card).

I was thinking I could do the same thing with the PixeLink camera, but I can't figure out how to send a software trigger to the camera to start the process... I have I/O, but that seemed less elegant, and I don't want to trigger based on the current because I'm not sure the camera will be fast enough to catch the filament before the current goes away (1ms)...

Ideally, I'd like to use mode 2 (swtrig - shutter opens, stimulate, swtrig shutter closes and gives me data).

So... should I be trying to do this a different way, or...

Thanks,

Thor Johnson

[s_a_s]

Hello Thor,

Most of the trigger modes available for the IMAQ 1394 Configure Trigger VI require an external trigger to the camera hardware.  The only mode (if your camera supports it) that will allow an internal trigger is mode 3.  This may not be the ideal for your application as it causes the camera to issue an internal trigger on a cycle time that is N times the parameter input for the IMAQ 1394 Configure Trigger VI.  From what I inferred from your post,  your application is asynchronous so a cyclical trigger is probably not what you want.

Since you are trying to avoid using hardware I/O or triggering, another option would be to use a LabVIEW state machine or event structure to perform a snap when a button on the front panel of your VI is clicked.  After the acquisition you could do any image processing or file management you need.  The problem with software based triggering is that it is non-deterministic, but if your application is forgiving enough to allow for a few ms delays this may be a pretty good option.