How can I do a bit mask?

[garya505]

How can I do a bit mask in LabVIEW?  For example, what the easiest way to see if bit 3 is set in a 32-bit unsigned int?

[dan_u]

AND the U32 with another U32 with the 3rd bit set to 1 (easy to do in binary formatting).

To set a bit, use the OR operator.

Boolean operators work very nice with integer numbers.

Message Edited by dan_u on 03-12-2010 01:06 AM

[Yamaeda]

your int AND 4 (or change visual option of the '4' to binary and write '100')

Then either compare to 0, 4 or >0.

/Y

[jyang72211]

Given: X is the input for bit 3 testing

1. X AND 8 = y (notice that at is 00000000000000000000000000001000 binary in decimal)

2. Convert y to a boolean array = z

3. Or all element in array(z) = result

If result is true, bit 3 is set.  If not, bit 3 is clear.

Yik

[jcarmody · Accepted solution]

As already said, AND.

 

[Ray.R]

Well explained Jim.

If you do a bit mask and the bit(s) you are looking for is set, then it does not matter what the answer is, it will not be zero.  So result != 0 means the bit was set.  🙂

[garya505]

Thanks to all for the great answers!  My first reading of the LV Help for AND led me to think it was only boolean, not bitwise.