Garmin GNC 255, Installation Manual, Page: 98 / 138

GTR 225/GNC 255 TSO Installation Manual 190-01182-02
Page B-18 Rev. B
k = desired frequency in KHz, where k = (desired frequency / 25KHz) + 30h,
with desired frequency in range of 000 to 950KHz. Note that valid NAV
frequencies only lie on 50KHz boundaries (i.e. 108.00, 108.05, 108.10, etc.).
“N” ..........................Reserved.
Example message:
$PGRMV28E4?PN<chksm><CR><LF>
Active NAV frequency is 117.100 MHz, Standby NAV frequency is 111.800 MHz.
B.2.4.2.12 NAV Audio Mode
This message is used to output the current NAV audio mode. There are two possible settings for this mode.
There are two possible settings for this mode. The first is “IDENT”, which will suppress the voice portion
of the NAV audio signal and emphasize the Morse Code station identifier (unit will display “ID” in the
upper-left corner of the NAV page). The second choice is “VOICE”, which will emphasize voice signal
and suppress the Morse Code station identifier.
Message format:
“V” ..........................Message class. This is a VHF NAV message.
“29”.........................Message identifier.
a...............................NAV audio mode. “I” = IDENT, “V” = VOICE
Example message:
$PGRMV29I<chksm><CR><LF>
The current NAV Audio mode is “IDENT”.
B.2.4.2.13 NAV Volume Level
This message is used to output the NAV volume level.
Message format:
“V” ..........................Message class. This is a GNC NAV message.
40 ............................Message ident.
vv ............................Volume level: 00-FFh; use encoded hex (30h-3Fh).
Example message:
$PGRMV4030<chksm><CR><LF>
The headphone volume level is 30h out of FFh.