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

Subject: Re: state notation code flags
From: Patrick Thomas <thomas_p@ligo-wa.caltech.edu>
To: Mark Rivers <rivers@cars.uchicago.edu>
Cc: tech-talk@aps.anl.gov
Date: Fri, 02 Oct 2009 17:29:42 -0700
This also prints out the flag:

program sncTest

float test_put;
assign test_put to "H3:TEST_PUT";
monitor test_put;
evflag test_putEvent;
sync test_put test_putEvent;

float test_get;
assign test_get to "H3:TEST_GET";
monitor test_get;
evflag test_getEvent;
sync test_get test_getEvent;

ss ss1 {
	state init {
		when () {
			efClear(test_getEvent);
			pvGet(test_get);
			if (efTest(test_getEvent)) {
				printf("flag set\n");
			}
		} state wait

/*
		when () {
			efClear(test_putEvent);

			test_put = 40;
			pvPut(test_put, SYNC);
			efClear(test_putEvent);
		} state wait
*/
	}

	state wait {
/*
		when () {
			if (efTest(test_putEvent)) {
				printf("flag set\n");
			}
		} state wait
*/
		when () {
		} state wait
	}
}



Mark Rivers wrote:
Patrick,

pvGet will not set the event flag.  Event flags are only set on monitor
callbacks, i.e. when the value changes in the IOC and it does callbacks
to channel access clients that have subscribed to that channel.

pvGet(pv) normally blocks for the operation to complete, so it gives the
same behavior as pvGet(pv, SYNC) (unless you compiled with the +a
option, which I would not recommend).

pvPut(pv) and pvPut(pv, SYNC) do behave differently, because the default
behavior is not to wait for the pvPut to complete, adding the SYNC
option forces it to wait for the put to complete.

Mark


-----Original Message-----
From: Patrick Thomas [mailto:thomas_p@ligo-wa.caltech.edu] Sent: Friday, October 02, 2009 1:25 PM
To: Mark Rivers
Cc: tech-talk@aps.anl.gov
Subject: Re: state notation code flags

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

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