RoyalTek RGM-3800 - Manual (Page 43)

Datalog GPS receivers
Contrary to a “pure” GPS receiver the datalog GPS
receivers store the received data to an internal memory.
Being switched on, datalog GPS receivers start writing
the position, date, and time into a log file. This logged
data can be read and saved on e.g. a PC. So the data is
also available for other applications like the locr PC
Client.
Note: Different datalog GPS receivers create log files in different
formats. How these files can be used with the locr PC Client is
explained here: “Which GPS datalogger can I use for automatic
geotagging anyway?”