The filtering works fine, the problem is the conversion to a double array, the variant to data will not accept array as the type.
Do the conversion in a for-loop; wire the output of the filter function to a for loop, auto.indexing on...convert the elements to double inside the loop...and wire the results out of the loop with auto-indexing to create the result array.
A better alternative though is to wire the array to a NaN? function and wire the resulting boolean array to the conditional auto-index tunneling.vi together with the original double array...the output will be the filtered signal.
