I have a working system with a L70-R module with a backup battery always connected to the module. The module behaves correctly, the satellite signal is good and I get the NMEA messages.
I need to know the exact behaviour of the “UTC time” field in GPRMC packets while this two conditions:
zero used satellites, no fix. I suppose the field reports the time from the internal battery-powered RTC. Is it correct?
some used satellites, but too few to have the fix. Does the field always reports the time from internal RTC or does it try to take some information from the satellites?