For-Loop Bug in LV7.1

Question

There is a bug in LabVIEW 7.1 where you have a for-loop, a constant outside
the loop, a constant inside the loop and a subtraction of the two constants.
What you have to do to see the bug is:
- Place a for-loop on the diagram
- Wire a constant with any value to the count terminal
- Place a constant on the diagram outside the for-loop, use any postive
number
- Place a constant inside the for-loop, use any positive number
- Place a substract-icon inside the for-loop
- Wire the constant outside the loop to the substract-icon
- Wire the constant inside the loop to the substract-icon
- Wire the result of the substraction to the output of the loop and disable
indexing
- Wire the input of the constant outside the loop directly to another output
of the
loop and disable indexing
- Probe the output of the subtract.
- Run VI
What you will see is that the output constant is treated as 0
Same thing with addition, multiplication, division...
When you change the outside constant to a control it works.
When you remove the direct output from the outside constant through the loop
then it works.
This has been submitted to NI as a bug report, so hopefully there will be a
fix soon.

Answer 1

Hi,
Isn't this exactly the same bug as the bug reported a few days ago ("Major
bug in LabVIEW math", by damsem)?
It was painfull enough the first time...
Regards,
Wiebe.
"Konima" wrote in message
news:[email protected]..
> There is a bug in LabVIEW 7.1 where you have a for-loop, a constant
outside
> the loop, a constant inside the loop and a subtraction of the two
constants.
>
> What you have to do to see the bug is:
>
> - Place a for-loop on the diagram
> - Wire a constant with any value to the count terminal
> - Place a constant on the diagram outside the for-loop, use any postive
> number
> - Place a constant inside the for-loop, use any positive number
> - Place a substract-icon inside the for-loop
> - Wire the
constant outside the loop to the substract-icon
> - Wire the constant inside the loop to the substract-icon
> - Wire the result of the substraction to the output of the loop and
disable
> indexing
> - Wire the input of the constant outside the loop directly to another
output
> of the loop and disable indexing
> - Probe the output of the subtract.
> - Run VI
>
> What you will see is that the output constant is treated as 0
> Same thing with addition, multiplication, division...
>
>
> When you change the outside constant to a control it works.
> When you remove the direct output from the outside constant through the
loop
> then it works.
>
> ----
> This has been submitted to NI as a bug report, so hopefully there will be
a
> fix soon.
>
>