Fixed point issue with Feedback Node in FPGA

[tintin_99]

Hi 

In the attached LabVIEW FPGA code I get the following error when I try to complie the code:

LabVIEW can not determine the size of the array output because arrays of
different sizes are wired to the Feedback Node.

Could you please let me know how can I resolve this issue
and make the input "fixed size "to the Feedback Node?

[RavensFan]

How many elements do you have defined in the boolean array going into the initializer of the feedback node?

[tintin_99]

That one is also 24. So I get data from 24 IOs ,  initializer array has 24 elements and the array subset VI also passes 24 elements and I don't know why I get this error

[RavensFan]

What if you don't use the boolean array to number which is outputting a U32.  Maybe 32 bit vs. 24 booleans is confusing it.

[tintin_99]

I deleted the Boolean array to number and replaced it with a Boolean array indicator and changed the type to 24bit fixed and I see a red dot on the input terminal. 

And I get the same error when I complie.

The input to the Feedback Node is ID array of Boolean (not fixed size ) and the output from Feedback Node is also not fixed size .

[dan_u]

On the FPGA all arrays must be fixed size. Make sure the constant array wired to the initializer is set to fixed size 24 elements.

[GerdW]

Hi,

what happens when you convert the boolean array to number directly after reading your inputs and do all that ANDing on U32 values?

(Why do you need a feedback node here at all?)

[Dragis]

If you hover over the wires and look at the context help do all of the arrays show a fixed-size of 24 elements?

The only way I could reproduce your issue was by having the initializer constant value set to a size other than 24 elements. My example wasn't exactly the same as yours, but from the compilers perspective they should be identical as far as the array sizes are concerned.