imgSessionConfigure took more than 600 ms in IMAQ 3.x !

[YR]

Hi,

I'm frequently changing camera attribute for changing integration and shutter time.

It took less than 100 ms to stop and restart grab or ring in IMAQ ver 2.x

But, after I upgraded IMAQ to ver. 3.x,
I found that it took long time.... more than 600 ms.....

It's imgSessionConfigure that takes time...

It's so important for us to spend short time for switching camera integration and shutter time.

Please, let me know how to shorten this time

Thanks in advance.

[nipun]

Hello YR,

It is possible that the newer driver has more error checking built into it that is increasing the configuration time. If your camera is able to receive serial commands to change the shutter speed then that is a seamless process and does not require you to reconfigure the inspection.

Regards,
Nipun M

[YR]

Hi, nmather,

Yeah, I'm changing shutter via serial command, not stopping acquisition.

But, for changing integration, I could not find any other way except using camera attribute, which requires stopping acqusition.

Now, to stop and restart acq. spends 780 ms....

Isn't it toooo long time?

Pls, let me know even some non-official hints....

Regards.

PS) I'm struggling with Pulnix 6710CL camera.

[nipun]

Hello YR,

Instead of using IMAQ set camera attribute.vi, which sends the serial command listed in the camera file try using "IMAQ serial write.vi" and specify the serial string that needs to be sent. Hope this helps.

Regards,
Nipun M

[Ken Pietrzak]

YR,

We had a similar issue with an SVS camera. We found that we could break up the IMAQ Start VI and place everything up to and including the imgSessionConfigure into an initialization VI and only call it once. The acquisition VI simply called the set attribute VI to change integration time and then called imgSessionAcquire and getbuffer. We only called IMAQ Stop when closing the application. Our acquisition time is much, much, faster now. Hope this helps.

Ken Pietrzak
www.dragonflycomputing.com

[YR]

Hi, Ken.

Thanks for your valuable information.

Actually, I'm using VC++, not LabView, but your tip helps me so much.
Now, it takes 0 ms to re-start acquisition.

Thanks so much again.

[YR]

Hi, Ken,

Would you help me one more ?

I succeed to stop/start acquisition in 0 msec.

But, I found that the captured image is shifted somehow.
The number of shifted pixels varies whenever I restart acquisition.

Could you give me some remedy for this phenomenon ?

Thanks in advance.

YR

[Ken Pietrzak]

Hi YR,

I'm glad to hear that you've reduced your acquisition time, but it still should take some time for image readout, e.g. # of pixels / clock frequency. What is your actual acquisition time now?

I don't understand why your image would suddenly be shifted. Perhaps there is something wrong with your camera file. Have you verified that the shifting problem goes away when you use the standard IMAQ acquisition?

Ken Pietrzak
www.dragonflycomputing.com

[CitySmall]

HI YR MEMBER, I also have this ImgSessionconfigure problem which takes a long time to configue, like 800-1000ms. It`s said that you  have solved this problem in c/c++. can you detail your solution, since I can not found a suitable way to do it.

[BlueCheese]

What version of IMAQ are you using? There were some improvements made to the speed of the Configure function a while ago that may help quite a bit if you are coming from an older version.