There are three ways that a USB device will show up in MAX.
1. If the vendor implements a USB->RS232 scheme, then the device will show up as an additional com port. You can then communicate to it just like any other RS232 serial device.
2. If the vendor implements the device as a USBTMC device. This is the USB Test & Measurement Class. Vendors such as Agilent, Tek, etc. use this and their instruments with a USB connection are programmed just like their GPIB instruments.
3. Follow the instructions at
http://zone.ni.com/devzone/cda/tut/p/id/4478 and define your own VISA interface to the device. While using the wizard to create a VISA device is not that hard, getting the information on the exact protocol the vendor has used for the messages can be quite difficult to get. If the vendor provides a dll and an api for the dll, that is often much easier to use with LabVIEW's Call Library Function Node. Sometimes instead of a dll, the vendor might provide an ActiveX interface that is dcoumented. This could be controlling an application program that the vendor provides.
