we are using the EM7455 in OnBoardUnits for vehicles (mostly railway) with LTE and GPS/GNSS capabilities.
On some of theses boxes GPS /GNSS fix reproducible seems to get lost after some hours of operation.
(so GPS is working in general)
We are using the NMEA-serial interface (/dev/ttyUSB1) in Linux environment and the AT-Command
interface (ttyUSB2) for controlling (and getting information about mobile network).
Whenever this problem happens I still get NMEA-data from EM7455 but with “no location”
(p.e. ‘GPRMC’ with “Void” marking). If I reset the device in this situation GPS is almost instantly again
available. (so antenna, power supply or simple vehicle “parking situation” could be excluded
from causing this.)
Is there a proper way to get this device to keep alive the GNSS receiver? Or is there some other
recommended way to “reactivate” GPS (without reset)?
Any hints are welcome - thanks.