User's Manual

Geospatial information
This command repeats the most recent $GN message, or queries or sets the $GN message rate.
$GN <@|?|<rate>>*xx
Parameter
Description
@
Repeat most recent $GN message
?
Query current $GN rate
rate
Disable or set rate of $GN messages
Returns one of:
Value
Description
$GN
<latitude>,<longitude>,<altitude>
,<course>,<speed>*xx
The most recent $GN message. See
Geospatial Information - Unsolicited
Messages for more detail on the outputs of
this message
$GN <rate>*xx
The current $GN rate
$GN OK*xx
Parameters updated successfully
$GN ERR*xx
An error response
Notes:
For the query option, the return value of $GN <rate>*xx requires different parsing than the 
normal $GN message format. The application should check if a comma is present in the $GN
string, and, if so, assume it is the standard geospatial information format. If no comma is present
and the value is a number, then the value is the rate being returned in response to the $GN ? 
query.
<rate> is a value between 1 and 2147483647 (2
31
-1). It will be the number of seconds in
between each message.
31