Filter Event Bug

[Ed Dickens]

Greetz All,

Last week, I was in on a discussion on the Developer Exchange concerning a bug in the Filter Events. The entire thread with examples can be read at the link below.

Filter Event Bug Thread

The basics of it is this. If you are using a filter event to modify some data, you shouldn't operate on that data in the filter event case unless you want to use the modified data. It seems that when you write to the filter event terminal on the right side of the structure, it modifies the data that gets operated on in memory even though execution highlighting, probes and front panel indicators display the unfiltered data.

So using the attached example with execution highlighting on, right click on the front panel to fire the Mouse Down? event and generate a '2' for the button value. Watch the diagram and you see the left hand Button terminal generate a 2. The 2 is wired to the equal function along with a constant 2, they are compared and the Equal generates a False.

An NI App Eng checked into it and has verified it as a bug. He said memory space is being shared where it shouldn't be. The workaround for now is to force the writing to the right Button terminal until after you have operated on the original value.

This bug has actually been in the filter events since the event structure was released in LabVIEW 6.1

Ed

Download File:post-47-1096290206.vi

[m3nth]

Interesting.

As stated in the posts you linked to, the workaround is just to update that terminal last... Download File:post-360-1096313878.vi