Leaderboard

There is not a way to do this. If you populate one element of a cluster, the rest must have values. If you leave them unspecified, it will default to whatever is set for that field. Using this behavior, you can set the default to sentinel values (e.g., NaN for a DBL) which allows you to detect "defaultness".

Your IT guy was wrong. If Windows Device Manager sees a serial port, its because there is a serial port. This may not be a normal serial port that is exposed to the outside world via a DB-9 but an internal one for diagnostic support. I've seen several PCs have internal serial ports that allows for for intimate access to the PC, or it is possibly a serial port that is only accessible through a dock that the laptop is connected to. In any case it is not going to be a serial port that is going to be available for communicating with other hardware and investing in a USB-to-RS-232 is going to be a good idea. I've heard some cheap ones don't work with all hardware, but I haven't found any hardware my no name cheapo couldn't talk to yet.