If you try to run a map, and you get a PORT_ALREADY_IN_USE error, then there are two possible causes:
Your instrument is configured for multiple users and another user has reserved ports that are also in your map. To determine which ports are reserved, use the Port Reservation dialogue.
Your instrument is NOT configured for multiple users but another user is connected to your instrument and is running a map; the running map uses one or more ports that are also used in your map. In this situation, there is no way to determine which map is running or who the other user may be.
...