Experimental Physics and
Industrial Control System

Ned Arnold <[email protected]> · Wed, 18 Aug 1999 09:09:04 -0500 (CDT)

Hi Len,

  As you might know, channel access has an array size limit of 16 Kbytes
  which greatly impedes passing images around via channel access.

  To overcome this, I developed an "image record" which treats each
  scan line of an image as an array. The image record has fields defined 
  for each scan line (e.g.  imageRecord.L1, imageRecord.L511, etc). CA clients 
  can retrieve the entire image by reading N arrays (where N is the number of
  scan lines). Smarter clients will read only lines that they are interested
  in (region of interest) thereby reducing network traffic.

  To get IDL (a client) to read an image from this record takes only a few
  lines of code.

  This is really for transmission between an ioc and a CA client, not
  "record to record". However, a CA client running on the ioc (e.g. sequencer)
  could certainly copy the necessary data to other records.

  If this seems approach seems helpful, send me a note and I'll send you 
  the record support. 

  	Ned

> Hi,
> 
> I have been developing some additional device and driver support
> for EPICS and am coming up to the task of interfacing our low end
> CCD camera head to EPICS via a Raster Graphics PMC Video Capture
> module (precisely this is the RG-101 PMC Color Graphics Board with
> Video Capture).
> 
> I am interested if anyone has developed image record code for EPICS
> which supports image acquisition.  Can NTSC image data be transfered
> from record to record.  My primary use for the image data is optical
> alignment.  We will aquire image data of Laser and LED points and
> do centrioding on them to position optics.  Would be interested if
> anyone else is doing similar types of things with EPICS.
> 
> Regards and thanks in advance for replies,
> 
> Len
>   
> -- 
> ____________________________________________________
> Leonard J. Reder
> Jet Propulsion Laboratory
> Interferometry Systems and Technology Section 383
> Email: [email protected]
> Phone (Voice): 818-354-3639
> ____________________________________________________

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System