Put a conditional breakpoints in there so that your code stops when you get a zero on those displays. Then stop your VI, make the values shown in the indicator the default values, save the VI and attach it.
There must be something wrong in that string coming in, perhaps you can't even see it (try turning on \code view) that is causing your values to turn to 0.
The thing is, we can't debug your code for you. We don't have your VI, we don't have your equipment, and we can't run it to see why you are getting invalid data. You need to use the debugging tools that are provided to figure this out. At least use the tools to provide us something we can look at.
