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

Subject: Re: state notation code flags
From: Patrick Thomas <[email protected]>
To: Mark Rivers <[email protected]>
Cc: [email protected]
Date: Fri, 02 Oct 2009 11:24:53 -0700
Hi Mark,

If I have the following:

float request_move_to_absolute_position;
assign request_move_to_absolute_position to "{IFO}:{DRIVER}_REQUEST_MOVE_TO_ABS_POS_{AXIS}";
monitor request_move_to_absolute_position;
evflag request_move_to_absolute_positionEvent;
sync request_move_to_absolute_position request_move_to_absolute_positionEvent;

...

pvGet(request_move_to_absolute_position);
efClear(request_move_to_absolute_positionEvent);

Will the pvGet set the request_move_to_absolute_positionEvent flag? If so, is it possible that even with the efClear, the flag will remain set at the end of the code, because the pvGet will not have completed before the efClear is encountered? But if pvGet(request_move_to_absolute_position, SYNC) is used, will this guarantee that the efClear will clear the flag?

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:[email protected]] Sent: Thursday, October 01, 2009 5:20 PM
To: Mark Rivers
Cc: [email protected]
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: [email protected] on behalf of Patrick Thomas
Sent: Wed 9/30/2009 10:35 PM
To: [email protected]
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 Mark Rivers
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

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