[Greg McKaskle]

You may already know this, but right click on the global and select Find>>References. It will bring up a list of the readers and writers. You can click or hit ctl-g to go from one to the next and think about how the writers may be interacting. Ideally, you will only have one writer, but if you need to update in more than one location, at first glance that seems impossible.

You may want to read up on functional globals in LV. Each non-reentrant subVI automatically acts as a critical section, ensuring that only one caller is active in the function at a time. This allows you to put data modifications within a common function to ensure that your parallel updates are playing nicely.

The single update also makes it easier to put traps into your code to break when the update value is zero. Feel free to ask more questions.

Greg McKaskle