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Can a tri-state buffer be implemented?

Hi.  I would like to implement a tri-state indicator...as in High, Low, and High-Impedance state.  Does anyone know of an easy or clever way to do this?  I have a buffer that drives an indicator, but I want to show that when the buffer goes active high, the bit it is driving is in high impedance; neither high or low.  Thank you!
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Message 1 of 9
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The easiest way of doing this I think would be to either use an LED boolean, and just change the colour, or a simple decoration and change the colour of that.  This however, depends on what you consider to be an acceptable indicator...
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Message 2 of 9
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the problem with that is I need a third color....green, red...blue
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@Adma wrote:
the problem with that is I need a third color....green, red...blue


Couldn't you use a makeshift mux?
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Is this the kind of thing you're looking for?


Message 5 of 9
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Thanks, as usual you guys are right on point.  Thats what I need
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Arbitrary number state buffers (including tri-state) can be implemented with a enum.  If you want a graphical control I would sugest using a picture ring.

 

Paul

Paul Falkenstein
Coleman Technologies Inc.
CLA, CPI, AIA-Vision
Labview 4.0- 2013, RT, Vision, FPGA
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Message 7 of 9
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I I would use a color box indicator dressed up as LED. For a simple example see my post here:

http://forums.ni.com/ni/board/message?board.id=170&message.id=129184&query.id=0#M129184

(The above example has 4 states, but I am sure you can simplify. ;). Of course if the state is determined by code, you don't want to use an event structure)

 

(This is similar to Novatron's example. Novatron, I don't uderstand why your colorbox is a control and you write to it using a value property. Why not make it an indiacator and place it at the location or the property node and delete the property node?  Your current approach has two disadvantages: (1) Since it is a control, the user can change the color during run, fighting the code. (2) You have all the performance overhead writing to value property nodes.)

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Message 8 of 9
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@Altenbach

You're completely right.  The reason it is like that is because I wasn't paying much attention!  I was doing some property node stuff at the time and I guess had them on the brain. 

Attached is the way that this should be...

Sigh.  I hate Mondays.
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Message 9 of 9
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