94
Motorola GPS Products
M12 Oncore User’s Guide Supplement
Revision 1.0 01/25/00
GPGGA (GPS FIX DATA)
This command enables the GPGGA GPS Fix Data 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 value of the periodic rate is retained through a power cycle
only if battery backup power is applied.
If the receiver has just powered up and has yet to compute a position fix (GPS
quality indicator field (q) is zero), then the time (hhmmss.ss) and HDOP (y.y) fields
will be nulled. If the receiver is not currently computing a position fix sometime
after the first fix, (GPS quality indicator field (q) is zero), the time field (hhmmss.ss)
will be frozen and the HDOP field (y.y) will be nulled. If the receiver is not using
differential GPS (GPS quality indicator field (q) is not two), then the age of
differential data (t.t) and differential reference station ID (iiii) fields will be nulled.
NOTE:
Height reported in the GPGGA message is GPS height, and the geoidal
separation field (g.g) will always be null since the M12 Oncore does not
contain this information.
Default mode:
Disabled