Experimental Physics and
Industrial Control System

Jennifer Dunn <[email protected]> · Tue, 23 Feb 1999 14:55:34 -0800 (PST)

Hi,

I am creating a custom record, and have defined a field in the record to
have special processing at run time (special = SPC_MOD) and have the pp_value
set to YES (a passive record should be processed when Channel Access writes
to this field).

In the record support code I have a routine called special, that simple sets
a flag to indicate that the record was accessed - and then expect that
after special the "process" routine should be called.

Well, this appears to work as expected - most of the time.  Sometimes I
see that special is called and then some time later - much later -
the process gets called by "scanOnce".  This is a problem because I
set a timer (using the watchDog timer lib - wdLib), to keep time and tell
me if I have waited too long - and this times out before the process 
gets called.

So, sequence of events is:

-start watchdog timer at time <72103>
-value written to SPC_MOD field <73003> in an interrupt routine from a different
record.
-special is executed and flag gets set <73003>
-then some time later the watchdog timer finishs <73904> and the callback
routine gets called.
-and immediately following the process gets called as a result of the 
special being executed, but this is much too late <73904>.

So, can anyone help me?  I have a feeling it has to do with running the 
watchdog timer, but can't tell.  

I am running EPICS 3.12.2 & vxWorks on an MV167.

Jennifer Dunn

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System