I am using LabVIEW 8.6 to control an pump through USB (computer) to RS-232 adaptor (pump) using COM 4. The first time the VI runs fine. But After I quit the VI, and restart the VI. I can not access the same COM 4. Did I miss anything in closing the com port or in the initiation the com port. My VI is attached.
When you navigate to MAX, does the COM port show up with a yellow exclamation mark next to it? If it does, then please read this article on how to fix this problem.
