Sorry, there's something I don't get. Where is your sub vi for the instrument?
>From the looks of things, the capacitance value is examined to see if it is within the range 500 to 800, which stops the execution. This value seems to be coming from the 'Fract/Exp String to Number' structure. If you think it would be more helpful for explaining, I can be reached at [EMAIL PROTECTED] Thanks!