Can anyone set the ROI using the partial scan properties of a Basler a602f 1394/firewire camera in Format 7 Mode 0

[DanBurnham]

Dear All,

I have come across a problem similar to the one mentioned in the thread below,

http://forums.ni.com/ni/board/message?board.id=200&message.id=4478#M4478

Unfortunately, no one came up with a solution.

I've spent a while working out how to write to specific bits in the camera registers and can now change the image width and height. However, when I read from the register to obtain the total number of pixels per frame (for example) it still returns the number that is associated with an unchanged ROI. Also the displayed image is no smaller. The above thread probably explains the problem better.

Can anyone help?

Thanks

Daniel Burnham

[BruceAmmons]

Why don't you just stop the acquisition, change the ROI, then restart the acquisition?  It is all built in the the firewire drivers and is easy to do.  What is the advantage of using the registers to do it?

Bruce

[DanBurnham]

Thank you for the help. When I wrote my question altering the ROI via a property node did not seem to alter the actual frame size output from the camera. I repeated what I had done before and it now works.

That was a little odd but it works fine now.

I now have another problem...

I am now trying to increase the frame rate of the output from the camera using format 7 mode 0 settings. I have succesfully altered the shutter speed and hence exposure time, the AOI and also the bytes per packet. From what I understand if I alter the bytes per packet to the value recommended (Rec Bytes Per Packet) which I can read out from the camera register then I will achieve the maximum frame rate possible with my current settings.

I have managed to alter the bytes per pixel to recommended value and various others but it still only outputs ~25fps

The reason I am using the register for these more fiddly parts is that the inbuilt property node functions do not seem to change the settings.

Any help is greatly appreciated

Daniel Burnham

[BruceAmmons]

Dan,

I never use the registers, and everything works fine.

When I initialize the camera, I use a property node to make sure the camera is in format 7, mode 0.  I also make sure that Format7BytesPerPacket is 4096, which gives the fastest transfer rate.

Before I start an acquisition, I use a property node to set the shutter attribute for the speed I want.  This takes two inputs - the Attr (Shutter) then the Value.  This determines the frame rate for my application.  I think the camera explains how to calculate the exposure time for a given Shutter value.

When I configure the acquisition, I select continuous and use the Region of Interest input to specify the area of the image to acquire.

Be aware that most property nodes have to be set before the acquisition is started.  They are ignored during an acquisition.

Bruce