Discussion:
Event structure challenge Please help.
(too old to reply)
Bob
2010-02-18 02:00:02 UTC
Permalink
I have this bug that is driving me crazy. Spent 2 day's and still no where.
I won't ask why the most simple things are the hardest with labview becuase
that
will just open a can of worms. Anyway, here is what I can't figure out.

I have an ok button that is activated through a AI channel. When high
the button goes on as is should on the front panel. What I need to do
is have an event occur only when the button is back off when the signal goes
low. The problem is that events only handle mouse or keyboard movement.
They do handle value change but no good becuase you can't specify
from on to off or off to on. The second problem is I need nothing to happen
when the button is activted only when it goes from on to back off.
Sounds simple enough but it's not. When the AI signal goes low and button
is
false I need that to trigger a timer for given amount. I am no slouch with
labview
but this one has me puzzled. Any suggestions are badly needed here!

Thanks in advance.

Bob
Bob
2010-02-19 00:47:57 UTC
Permalink
Thanks for the replies. It alomost works except the new problem is
that it only works with the mouse. When triggered by the AI
nothing happens becuase the event structer hangs the loop.
Nothing executes with the AI.
Any ideas?
Post by Bob
I have this bug that is driving me crazy. Spent 2 day's and still no where.
I won't ask why the most simple things are the hardest with labview
becuase that
will just open a can of worms. Anyway, here is what I can't figure out.
I have an ok button that is activated through a AI channel. When high
the button goes on as is should on the front panel. What I need to do
is have an event occur only when the button is back off when the signal
goes low. The problem is that events only handle mouse or keyboard
movement.
They do handle value change but no good becuase you can't specify
from on to off or off to on. The second problem is I need nothing to
happen when the button is activted only when it goes from on to back off.
Sounds simple enough but it's not. When the AI signal goes low and
button is
false I need that to trigger a timer for given amount. I am no slouch with
labview
but this one has me puzzled. Any suggestions are badly needed here!
Thanks in advance.
Bob
Bob
2010-02-19 16:13:17 UTC
Permalink
Will try to post code. I have 2 loops. The event is in it's own loop.
Still don't understand why value change is not value change.
Seems labview is quite dumb in this regard. The value is being changed
through AI on one loop passed through local varibale to the event loop.
as I said, When you change value with the mouse I get desired result
but when triggered though local varibale or property node the event is not
detected even though the button does change on the FP. It's probably a
simple fix but I guess I don't know enough. This almost seems like a bug. As
I said.
I recall in past versions that no matter how you changed the value it was
detected.
I can't put the event in the AI loop as it has sound incorperated. what
happend then is the loop is frozen as the even structure is waiting.
Post by Bob
Thanks for the replies. It alomost works except the new problem is
that it only works with the mouse. When triggered by the AI
nothing happens becuase the event structer hangs the loop.
Nothing executes with the AI.
Any ideas?
Post by Bob
I have this bug that is driving me crazy. Spent 2 day's and still no where.
I won't ask why the most simple things are the hardest with labview
becuase that
will just open a can of worms. Anyway, here is what I can't figure out.
I have an ok button that is activated through a AI channel. When high
the button goes on as is should on the front panel. What I need to do
is have an event occur only when the button is back off when the signal
goes low. The problem is that events only handle mouse or keyboard
movement.
They do handle value change but no good becuase you can't specify
from on to off or off to on. The second problem is I need nothing to
happen when the button is activted only when it goes from on to back off.
Sounds simple enough but it's not. When the AI signal goes low and
button is
false I need that to trigger a timer for given amount. I am no slouch
with labview
but this one has me puzzled. Any suggestions are badly needed here!
Thanks in advance.
Bob
CL
2010-02-22 08:09:54 UTC
Permalink
Post by Bob
Will try to post code. I have 2 loops. The event is in it's own loop.
Still don't understand why value change is not value change.
Seems labview is quite dumb in this regard. The value is being changed
through AI on one loop  passed through local varibale to the event loop.
as I said, When you change value with the mouse I get desired result
but when triggered though local varibale or property node the event is  not
detected even though the button does change on the FP. It's probably a
simple fix but I guess I don't know enough. This almost seems like a bug. As
I said.
I recall in past versions that no matter how you changed the value it was
detected.
I can't put the event in the AI loop as it has sound incorperated. what
happend then is the loop is frozen as the even structure is waiting.
Post by Bob
Thanks for the replies. It alomost works except the new problem is
that it only works with the mouse. When triggered by the AI
nothing happens becuase the event structer hangs the loop.
Nothing executes with the AI.
Any ideas?
Post by Bob
I have this bug that is driving me crazy. Spent 2 day's and still no where.
I won't ask why the most simple things are the hardest with labview
becuase that
will just open a can of worms. Anyway, here is what I can't figure out.
I have an ok button that is activated through a AI channel. When high
the button goes on as is should on the front panel. What I need to do
is have an event occur only when the button is back off when the signal
goes low.  The problem is that events only handle mouse or keyboard
movement.
They do handle value change but no good becuase you can't specify
from on to off or off to on. The second problem is I need nothing to
happen when the button is activted only when it goes from on to back off.
Sounds simple enough but it's not.   When the AI signal goes low and
button is
false I need that to trigger a timer for given amount. I am no slouch
with labview
but this one has me puzzled. Any suggestions are badly needed here!
Thanks in advance.
Bob
a screenshot would be nice ;)

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