Experimental Physics and
Industrial Control System

Marty Kraimer <[email protected]> · Wed, 11 Jun 1997 09:31:09 -0500

Ralph Lange wrote:

> > Note that onceTask scans a record. Since records can be linked,
> > this means an arbitrary number of records can process. This means
> > an arbitrary set of record/device/driver support can be executed.
> 
> Could I possibly be right if I assume that this might be valid for db links
> only, since ca links are executed by filling the event queue and waking up
> a ca event handler which then calls scanOnce() again starting another turn
> of this mechanism?

Yes this is correct.

An additional point.
For databases with many many database to ca links,
it is possible to fill the ring buffer even id onceTask
has not crashed. The ring buffer is set to 1000 entries.
It is possible to override this in the startup file via

scanOnceSetQueueSize(size)

This must appear before iocInit.

If however onceTask crashes, however, the ring buffer will ultimately
fill up.

Marty Kraimer

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System