Re: state notation code flags

["Pete R. Jemian" <jemian@anl.gov>]

sounds a bit off ... show the code

Patrick Thomas wrote:
> I think I have it narrowed down. It appears that when I set variable1 
> equal to variable2 and variable2 has a flag synced to it (variable1 does 
> not), and then do a pvPut on variable1, sometimes the flag is set on 
> variable2 and sometimes it isn't. Am I correct? Why does this occur?
> Thank you,
> Patrick
>
> Mark Rivers wrote:
> > Patrick,
> >
> > Event flags can be explicitly set, which is typically used to allow
> > communication between state sets.  Or event flags can be synced to a PV,
> > and will be set whenever a monitor is received for that PV, as in the
> > example I sent you.
> >
> > You can use the efTest() function outside of a when statement, just like
> > any other function.
> >
> > Mark
> >
> >
> > -----Original Message-----
> > From: Patrick Thomas [mailto:thomas_p@ligo-wa.caltech.edu] Sent: 
> > Thursday, October 01, 2009 5:20 PM
> > To: Mark Rivers
> > Cc: tech-talk@aps.anl.gov
> > Subject: Re: state notation code flags
> >
> > Hi Mark,
> >
> > Are the flags on a monitored variable set whenever the monitored 
> > variable is used in the code, including a pvPut, pvGet, assignment, 
> > calculation, or print statement? Is there a way to test if the flag is 
> > set besides an efTest in a when statement?
> > Thank you,
> > Patrick
> >
> > Mark Rivers wrote:
> >  
> > > Hio Patrick,
> > >
> > > Here are some code snippets from one of my SNL programs.  It has a
> > >     
> > variable nelements assigned to a PV, and a monitor on that PV.  It has
> > an event flag, nelementsMon that is synced to nelements.  Whenever
> > nelements changes the event flag will be set.  In the init state I clear
> > the event flag, just to be sure it is clear when the SNL code starts
> > running (after all PVs connect).  I then use efTestAndClear in a when
> > statement to take actions when that event flag is set, and to clear it.
> > This works fine for me.
> >  
> > > int     nelements;   assign nelements    to "{P}{R}Nelements.VAL";
> > > monitor nelements;
> > > evflag nelementsMon;    sync nelements  nelementsMon;
> > >
> > >
> > >     /* Initialize things when first starting */
> > >     state init {
> > >         when() {
> > >             /* Clear all event flags */
> > > ...
> > >
> > >             efClear(nelementsMon);
> > >         } state monitor_inputs
> > >     }
> > >
> > >
> > > ...
> > >
> > >     state monitor_inputs {
> > >
> > > ...
> > >
> > >         when(efTestAndClear(nelementsMon) && (nelements>=1)) {
> > >             /* If nelements changes, then change endPulses to this
> > >     
> > value,
> >  
> > >              * since this is what the user normally wants.  endPulses
> > >     
> > can be
> >  
> > >              * changed again after changing nelements if this is
> > >     
> > desired. */
> >  
> > >             if (moveMode == MOVE_MODE_RELATIVE)
> > >                 endPulses = nelements;
> > >             else
> > >                 endPulses = nelements-1;
> > >             pvPut(endPulses);
> > >         } state monitor_inputs
> > >     }
> > >
> > > Mark
> > >
> > > ________________________________
> > >
> > > From: tech-talk-bounces@aps.anl.gov on behalf of Patrick Thomas
> > > Sent: Wed 9/30/2009 10:35 PM
> > > To: tech-talk@aps.anl.gov
> > > Subject: state notation code flags
> > >
> > >
> > >
> > > Hi,
> > >
> > > I was wondering if there is a way to track at what point in the state
> > > notation code evflags are getting set and cleared, or if someone could
> > > clarify under what conditions they get set. I'm having trouble with
> > >     
> > them
> >  
> > > getting set somewhere and not being cleared, but I'm not sure where.
> > >
> > > Thank you,
> > > Patrick
> > >
> > >
> > >       
> >   
--
----------------------------------------------------------
 Pete R. Jemian, Ph.D.                <jemian@anl.gov>
 Beam line Controls and Data Acquisition, Group Leader
 Advanced Photon Source,   Argonne National Laboratory
 Argonne, IL  60439                   630 - 252 - 3189
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    Education is the one thing for which people
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