$PGRMW
From APRSWiki
[edit] Additional Waypoint Information (PGRMW)
The $PGRMW sentence provides the ability to update a waypoint's symbol, altitude and comment.
$PGRMW,<1>,<2>,<3>,<4>*hh<CR><LF>
| <1> | Waypoint identifier |
| <2> | Altitude in meters |
| <3> | Symbol number in Hexadecimal up to FFFF. Uses the enumerated values as defined for symbol_type. |
| <4> | Comment string |
The following notes apply to the PGRMW input sentence:
- The waypoint identifier must exactly match an existing waypoint on the unit. If the unit cannot find a waypoint that matches the given identifier, the rest of the sentence will be ignored.
- See Garmin Device Interface Specification for the enumerated values of symbol_type.
- If the comment string contains more characters than the unit supports, the unit will ignore any characters beyond the size allotted for comments.
- No all units support this sentence.