requirements for digital video synchronization signals

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Hello,

we're preparing to grab a custom camera with our PCI-1422 frame grabber. I want to pass along the requirments for sync signals to the camera designer so that we'll be able to easily grab the video with a new .icd that we can define.

I would like to know what the miniumum are for both the frame and line invalid periods. This is the time where either sync signal sends a pulse where there is no data being transferred but is signaling the board that data is coming.

Also, I would like to know if the pixel clock needs to be active during the invalid or pulse period.

Based on other cameras, it seems like the sync pulses should be say a minimum of 4 pixel clocks long and the pixel clock should be active
. We're probably OK with this assumption but it would be good to know what the real requirement is so that we can get the data over accurately and reliably.

Thanks for your help,
Wes

[cld]

Wes,
The National Instruments digital framegrabbers (IMAQ 1424 & IMAQ 1422) require the following timing information from the camera:

-The Pixel Clock needs to be continuous (from line to line and frame to frame).

-The Line Enable (Horizonal Sync or HSync) should remain high for the entire line of pixel data. At the end of each line, the Line Enable will go low. The low state needs to be ~ 3 pixel clocks in duration to allow enough time for the framegrabber to reset for the next line of data.

-The Frame Enable (Vertical Sync or VSync) should remain high for the entire frame of pixel data. At the end of each frame, the Frame Enable will go low. The low state needs to be ~ 3 Line Enables in duration to allow enough time for the framegrabber to reset for the next
frame of data.

Below is a link that contains this information, and a link to a diagram.

http://ae.natinst.com/operations/ae/public.nsf/fca7838c4500dc10862567a100753500/e8030d8c9b12a2c186256aa9004c75fa?OpenDocument

I hope this helps!
Chris D
NI Applications Engineer

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Thanks Chris - the information is very useful.
I cannot, however, get the link to work - is that correct?

[cld]

Try this link:
http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/e8030d8c9b12a2c186256aa9004c75fa?OpenDocument
I hope this helps!