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Connecting a Serial GPS to a USB Port

Electronics Hookup and Configuration

If you have a Garmin USB GPS... 
Garmin USB support is native to current versions of Terrain Navigator Pro. For details and instructions, please see:
Connecting a Garmin USB GPS

Connecting all other GPS receivers, including non-USB Garmins, requires either a 9-pin serial port connection or a "virtual COM port" USB connection.
Many new PCs (especially laptops) have USB ports but do not have the standard 9-pin serial ports found on older computers. This is a major concern for GPS connectivity, because the NMEA specification used by most GPS units is designed for standard Serial communications and not USB. 

To solve the problem, you will need to purchase a "USB-to-Serial" port adapter. This device connects to your USB bus and allows you to attach standard PC serial devices (including GPS Data cables, PDAs, modems, serial printers, etc.) to your USB-only PC. These adapters, from Sealevel, Keyspan, Belkin, and other companies, are relatively low-priced ($40-$70.) Please note that the USB-to-Serial port adapter sold by "Radio Shack" is *not* able to handle the data transfer rate from GPS units, and is not recommended for in this manner.

Another option to consider is a USB GPS. This eliminates attaching a GPS to a GPS cable to a USB-to-Serial adapter to a PC. Instead, this one GPS unit attaches directly to the PC.

Please note that for a USB GPS to work with our current software products, it must include a driver for a "Virtual COM Port." This allows Terrain Navigator to connect to the GPS as if it were attached to a NMEA standard serial (COM) port. Most, but not all USB GPS units include this feature.

Related Information:
Determining the COM Port of a USB to Serial Adapter

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