This format can...
read waypoints
read tracks
This format has the following options: erase, erase_only .
Serial download protocol for the GlobalSat DG-100™, GlobalSat BT-335™, and GlboalSat BT-338X™GPS data loggers.
While the DG-100 has a button to record waypoints, they seem to be indistinguishable from trackpoints. Therefore, all points will be presented as trackpoints, regardless of whether they were recorded automatically or manually.
Example 3.12. Command showing DG-100 download and erase on Linux
gpsbabel -t -i dg-100,erase -o gpx /dev/ttyUSB0 outputfile.gpx
Example 3.13. Command showing DG-100 erase_only option on Linux
gpsbabel -t -i dg-100,erase_only /dev/ttyUSB0
The DG-100 provides a physical USB interface to the host computer, but internally it uses a Prolific PL-2303 chip to do this. So you must have drivers installed on your computer to recognize the PL-2303 and provide that data as a serial port to software like GPSBabel. Such software comes with the unit for Windows. Prolific provides software for Mac OS/X, but unfortunately their driver has a defect which makes it unstable with GPSBabel.
Erase device data after download.
This option erases the track log from the device after download.
Only erase device data, do not download anything.
Much like the erase this option erases the data in the GPS.
It does not transfer data before doing so, making it much faster. This may
be handy in a work flow where you want to transfer the data from the GPS,
check it on a map, and then remove it from the unit.