USB Speed vs Baud Rate Selection

The NovAtel USB driver will create three virtual serial ports for each GPS USB port on the GPS receiver. These virtual serial ports are given names like COM5, COM6, COM7, etc. You can use these virtual comport names to reference the USB port on the GPS receiver using the name as a 'handle' under common terminal software programs such as NovAtel's GPSolution4 or Windows' HyperTerminal. The baud rate that you select does not matter. The USB driver will accomodate the fastest data rate possible, which in turn will be dependent on your PC hardware and the number of other active USB devices that are in use at any given time. You will get the same data throughput if you select 9600 baud or 115200 baud; it does not matter. For example: If you try to collect RANGEA data at 20 Hz with a normal serial port at 9600 baud, the comport will quickly overflow because the volume of output data greatly exceeds the 9600 bits per second. If you try the same thing, collecting RANGEA data at 20 Hz using a virtual serial port that has been created by NovAtel's USB driver, and you set the 'comport' baud rate to 9600 baud, all the data will be handled without any overflow issues because the USB driver will ignore the virtual baud rate and handle the data at a high USB speed instead. Surprisingly, this feature holds true using GPSolution4 or HyperTerminal. Bottom line: the baud rate doesn't matter when setting up a virtual comport created by the NovAtel USB driver. The true throughput will be set by the USB port and not the serial baud rate selection. Note: when setting up your virtual serial port, it is ok to select the hardware handshaking option under the GPSolution4 "Device->Open" dialog box. The USB driver will handle connections made with hardware handshaking active or inactive. There is no advantage or disadvantage to selecting either option.