First, USB is not a port, it's a bus. You cannot treat it like it is a serial or parallel port. You use the access methods that are exposed by the device driver of the device you're connecting to.
Now I'm going to say something that may confuse you. If the device exposes itself as a serial device then you can talk to the device using normal serial port methods, like over COM1, or whatever port ID the device is setup as.
VB.NET serial port communication[
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