Image Acquistion Speed VBAI

[wardy tansil]

Hallo all,

im a newbie on this thema and am just starting to learn about the machine vision, etc. about a week ago.

I actually would like to go to the NI  vision training for 3 days in münich, but too bad its already full booked

So I need to wait a little longer for it.

I got the NI 1722 smart cam last week and have allready installed the VBAI on my laptop.

I have some "newb" questions about the VBAI  

1) I just builed a short counter and a loop in my state diagram. If I change the main window between the acquistion windows and state diagram windows, I have different speed of my counter. Why is it?

2) I make a single step with image acquistion with my smart cam. If I run the step mode. The pictures are fine. If I run the inspection, I have frame skipping. Do the start and end

on the step diagram have a big effect on the frame grabbing speed?

Thanks a lot in advance for any answer, advice and idea.

[Brad]

Good questions. When you're running the inspection using the Run button on the bottom, it just runs the selected state and not the entire inspection. When you're using the Smart camera (or any remote target), and you run in this mode, all the processing occurs on your PC, and we remotely tell the smart camera to start acquiring. Because everything is running locally and when we get to the acquisition step we just ask for the current image, the inspection does a good job of keep up, so you don't see the frame index skipping too much.

When you press the Run button at the top, this runs the entire inspection, and it actually downloads the inspection to the target and runs everything on the target. So things run slower because:

1 - VBAI has to retrieve all the results, from the target after each step

2 - Your computer probably has more RAM and a faster processor than the smart camera

3 - There's a lot of delays so the highlighting of the steps looks good in VBAI

Because of this, the camera has more time to acquire more images before the acquisition step is run on each iteration, so you see the frame index change by more since the loop rate isn't as fast because of these delays. When you run the inspection in Inspection mode, the inspection runs more quickly because VBAI doesn't have to transfer the results after each step, and there's no highlighting of the states to slow down the inspection. The Windows VBAI just polls the target every once in awhile to get the current state, so it's not as intrusive and doesn't slow down the target as much.

Key point to remeber: Inspections run at different speeds in Configuration mode when running just the state, Configuration mode running the full state diagram, and inspection mode, so don't be surprised if you see the frame index changing by different amounts when running in these three different modes.

Hope this helps,

Brad