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<== Date ==> <== Thread ==>

Subject: RE: state notation code flags
From: "Mark Rivers" <rivers@cars.uchicago.edu>
To: "Patrick Thomas" <thomas_p@ligo-wa.caltech.edu>
Cc: tech-talk@aps.anl.gov
Date: Fri, 2 Oct 2009 16:55:08 -0500
I don't think the fact that variable 1 was set to variable2 is relevant.

But if you do a pvPut on variable1 that could cause variable2 to change
in your IOC, depending on the database logic, etc.  When the event flag
is set on variable2 is the value changing?

Here is a way to help figure it out:  run the following EPICS command
from the shell:

camonitor variable2

That will print a message every time a monitor is sent for variable2.
It should print a message each time you get an event on variable2 in
your SNL program.

Mark


-----Original Message-----
From: Patrick Thomas [mailto:thomas_p@ligo-wa.caltech.edu] 
Sent: Friday, October 02, 2009 4:47 PM
To: Mark Rivers
Cc: tech-talk@aps.anl.gov
Subject: Re: state notation code flags

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
>>
>>
>>   
>>     
>
>   



Replies:
Re: state notation code flags Patrick Thomas
References:
state notation code flags Patrick Thomas
RE: state notation code flags Mark Rivers
Re: state notation code flags Patrick Thomas
RE: state notation code flags Mark Rivers
Re: state notation code flags Patrick Thomas

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