GLL - Geographic Position-Latitude/Longitude

GLL - Geographic Position-Latitude/Longitude

This command enables the GPGLL geographic position-latitude/longitude message and determines the rate at which the information is transmitted. The periodic rate field (yyyy) instructs the receiver either to output this message once (polled), or to output this message at the indicated update rate (continuously). Once the receiver is set to continuous output, the continuous flow can be stopped by sending a one-time (polled) output request. The receiver will output the response one final time, and then terminate any further message outputs. The receiver will output the response one final time, and then terminate any further message outputs. The value of the periodic rate is retained through a power cycle only if battery back-up power is applied.

If the receiver has just powered up and has yet to compute a position fix (GPS quality indicator (q) is zero), then the time field (hhmmss.ss) will be nulled. If the receiver is not computing a position fix sometime after the first fix (GPS quality indicator (q) is zero), then the time field (hhmmss.ss) will be frozen.

Input Command

• Set response message rate:

  $PMOTG,GLL,yyyyCC

  yyyy	update rate	0 .. 9999 seconds
  CC	optional checksum

Response Message

• Response to above command at selected rate:

  $GPGLL,ddmm.mmmm,n,dddmm.mmmm,e,hhmmss.ss,a*CC

  ddmm.mmmm,n	latitude
  dd	degrees	00 .. 90
  mm.mmm	minutes	00.000 .. 59.999
  n	direction	N = north, S = south
  dddmm.mmmm,e	longitude
  ddd	degrees	000 .. 180
  mm.mmm	minutes	00.00 .. 59.9999
  e	direction	E = east, W = west
  hhmmss.ss	UTC of position fix
  hh	hours	00 ..24
  mm	minutes	00 .. 59
  ss.ss	seconds	00.00 .. 59.99
  a	status	A = valid
  		V = invalid
  CC	checksum