If the GPS context data or :GNSS:POS? query return data contain values 512 or a very large altitude such as 67108863.968750, it's very likely that the GNSS module has not yet received a fix.

To determine if a GPS fix is obtained, could use either of these SCPI query commands:

  • :GNSS:REF? query returning a “GNSS” response, or
  • :STATus:QUEStionable:CONDition? returning a value that contains the bit position 9 with a ‘1’ (or 512) could be used as a detection method.

Also, make sure that :GNSS:ENABLE is 1 (ON) as well by using its query command.  Sending :GNSS:ENABLE at any time will cause the GNSS module to reacquire a fix, which could take a few seconds.  The fix acquiring also happens after power-up, restarting the device, or after a GPS antenna is attached.