Creating a two bit multiplexer

[SK@NIG]

A case structure is nothing more than a select for more than two possible options.

You have to select between two items --> use the comparison--> select

You have to select betwenn more than 2 items --> use a case structure with a numeric value as selector.

compared to C it´s similar to use if/else or switch/case .

I my post above, you can download the VI snippets (drag into a block diagram of LV 2009 - When using IE drag and drop, when using Firefox, save as on desktop and then drag/drop)

[Getwonder]

To GerdW
And how to control the four digital inputs through one numeric input 

[GerdW]

Hi Intelligent,

as you have 4 possible output values you need 4 inputs to provide them(plus the additional "multiplexer" input)!

Or what else do you ask for???

[Getwonder]

I mean the decision inputs. which will be 1-4 numeric values and the control input of the select function are also 4 but boolean so how to use them.

[GerdW · Accepted solution]

Hi Intelligent,

don't you have one selector input, which allows several values?

The easiest way to get a boolean value is by using a comparison function like "Input==1". Or how is it done in C?

As already said in message #8: "all you need is 4 Selects, 4 comparisons and a default constant". Please read answers you have been given carefully!

Message Edited by GerdW on 04-23-2010 10:54 AM

[SK@NIG]

Hi intelligent,

you´re now talking about 4 values and 4 (corresponding) selectors?

In your first post you asked for a 2-bit-multiplexer, now you have a 4-bit?

Independant if you have two or for bits:

You can build an array of Boolans, then convert the boolean array to a number and use this number as selector for a case structure.

You´ll find more hints under:

LabVIEW menu -> Help-> Example Finder ->  Fundamelntals-->  "Numeric and Boolean" and "Array and Cluster"

Or try GerdW ´s version with the 4 select and so on...

Message Edited by SK@NIG on 04-23-2010 04:07 AM

[Getwonder]

Thanks very much Mr. GerdW
I got the solution.
For information is there any method in which we should not be limited of using the comparison (equal to) parameter.
Thanks again.

[Getwonder]

hi SK@NIG
i was questioning to the solution provided by GerdW

[GerdW]

Hi Intelligent,

"not be limited of using the comparison (equal to) parameter"

You want to select an output value according to a parameter. So you have to compare that value! You could do the comparison by using functions from the comparison palette or let a Case structure do that for you or use an IndexArray to do so... They all do some comparison!

[Getwonder]

OK and Thanks again