Experimental Physics and
Industrial Control System

Ron Rechenmacher <[email protected]> · Wed, 07 Nov 2007 08:41:52 -0600

Hi,

I did a search of tech-talk for: timing event synchronization
The results along with my experience to date leads to the conclusion
that synchronization by 8 byte time stamp is the only synchronization that
CA currently provides. (please correct if wrong)

The question:

  I was wondering if there has ever been any (perhaps behind the scenes)
  discussion of adding additional synchronization information to the
  Channel Access protocol?

Perhaps, in addition to the timestamp, a "synchronizing event" structure, 
which would be NULL if not used, but would otherwise have an event type and 
event count.

At some linear accelerator facilities, there has been a move toward counting 
RF pulses and associating data collection triggered by the RF pulse with that 
pulse count.  Of course there would be a pulse count to time correlation also,
but many people seem to embrace the main data association (in archived data) 
being with an event count.

I've heard that there has been work on "beam flavors" at SLAC. (sorry if this 
is bogus information). But if in addition to a timestamp, data also has 
"flavor" information, then this could be considered a start to additional 
synchronization information?  Has there been work on this? and if so, has any 
progress reports been published?

Thanks,
Ron

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System