Site Master MS2085A/MS2089A Programming Manual : Programming with SCPI : Remote Programming Setup and Interface : USBTMC Interface Connection and Setup
 
USBTMC Interface Connection and Setup
The Universal Serial Bus (USB) architecture is a high‑performance networking standard that is considered “plug and play” compatible. The USB driver software is automatically detected and configured by the operating system of the devices that are connected to the bus. The instrument USB C port must be used for remote program interface. This port conforms to the USB 3.0 standard and supports data rates of up to 5 Gbit/s with the following restrictions:
One USB network can support up to 127 devices.
The maximum length of USB cables between active devices is 3 meters for USB 3.0, 5 meters for USB 2.0, and 3 meters for USB 1.0.
The following USBTMC features are not yet supported:
SET_FEATURE
SYNCH_FRAME
For remote USB control, the controller PC must have a version of VISA installed that supports USBTMC (USB Test and Measurement Class) devices. Refer to http://www.ni.com/visa/ for software downloads and installation instructions. The USB C port connector can be used to connect the MS208xA directly to a PC. The first time the instrument is connected to a PC, the normal USB device detection by the computer operating system takes place.
The USB C port must be used to connect the MS2085A/89A directly to a PC. The first time the instrument is connected to a PC, the normal USB device detection by the computer operating system takes place.
1. Power on the instrument and controller PC and wait for the systems to power up completely.
2. Connect the USB port C cable connector to the instrument.
3. Connect the USB port A cable connector to the controller PC USB host port. The controller PC generally installs the driver software in the background and briefly displays a notification balloon near the system tray when the device is ready for use and the setup is then complete.

Some configurations will display a “New Hardware Found” dialog and you will then need to complete the remaining steps in this procedure by clicking Next.
Found New Hardware Wizard
4. Select to allow the Wizard to search for and install the USB software automatically.
Found New Hardware Wizard
5. After the software finishes installing, close the Wizard by clicking Finish.
Found New Hardware Wizard
 
Note 
The USBTMC connection interface does not work with instruments installed with secure communication Option 17.