why is my framerate so low

[angelo@ibsen]

I have set up a system based on a 1408 framegrabber, equipped with a standard Sony PAL CCD camera.
When running a continous image acqusition based on standard IMAQ VIs, I typically get 1-2 frames/sec.

I tried a low-level buffer-based acqusition ring, derived from your sample cope. With this I got 5-7 frames/sec. A significant improvement, but still no way near the 25 frames/sec delivered by the camera.

What am I doing wrong ? How do I get 25f/s from a standard 1408/ccd configuration ?

System:
AMD K6-2 500MHz, 256Mb ram.
IMAQ-1408 with Sony CCD connected to the coax input.
LabView 6i, IMAQ-Vision, Win98.
No external triggering og sync'ing is made.

[BruceAmmons]

You shouldn't have any problems. Chances are you are using snap instead of grab. Another possibility is that you aren't using an IMAQ display window.

The first thing I would do is use MAX (Measurement and Automation Explorer) to check out the hardware. Make sure everything is configured properly for your camera. Next, press the grab button and check what the FPS is. It is displayed in the lower right hand corner, and should look like 25/25. The first number is how many are frames are being displayed per second, and the second number is the number of frames being acquired per second. If this is correct, then you have a problem with your LabVIEW program. I would start with an unmodified example of GRAB and display in an IMAQ window. Make sure you ar
e trying to display using an IMAQ window. Converting the image for display in a picture control or intensity graph really slows things down. If you don't have the vision toolkit, there is way to get an IMAQ type window using DLL calls. There is an example somewhere in NI's support web site.

Bruce

[angelo@ibsen]

Hi Bruce, thanks for the advice.

I tried viewing the source in MAX, and it only displayed the same 5-7 f/s. The acquired framerate is 25f/s, as it's supposed to be.

So it seems to be a problem with the transfer of the data from the IMAQ board to the system.

How can I find out whether the problem is in the 1408 board, the PCI transfer, the RAM handling, the OS, Labview etc etc ?

The IMAQ manual recommends using a motherboard with a Intel 430/440 chipset. How important is this ? My system uses a VIA chipset. Could this the problem ?

Best regards.
Casper Angelo

[BruceAmmons]

Casper,

This goes beyond my realm of expertise. It sounds like your video display just can't keep up, but I don't know what the solution is. I would recommend giving NI tech support a call.

Bruce