There's nothing wrong with LabVIEW. The problem is with the way the command is defined in the manual. The correct syntax is INTF:R449V35:TYPE 422_T. Notice the underscore instead of the dash. There are several other mistakes in the manuals for the various modules. If you find a command that doesn't work, the best way to determine the correct syntax is to set the instrument up manually and then run the query to determine the actual state. In this case doing a INTF:R499V35:STATE? would return "422_T".
