Garmin NavComm SL30, Installation Manual

Page: 76 / 88

Serial Interface Specifications
68 Apollo SL30 Installation Manual
Example message:
$PMRRV28?PM<chksm><CR><LF>
This example command would set the standby VOR frequency to 111.800 MHz. This is
interpreted by noting that the ASCII ‘?’ corresponds with 3Fh, +30h = 7Bh, converted to decimal
equals 111 for the MHz portion. The kHz portion converts ASCII ‘P’ to 50h, -30h yields 20h,
x25 kHz steps = 800 kHz. This command would also set the receiver function to monitor, so the
receiver would time-multiplex the active and standby VOR channels to track both stations.
Note: The SL30 will check input frequencies for validity. An RS-232 serial error message output
will be generated if the frequency is invalid.
S
ET
S
TANDBY
COMM F
REQUENCY AND
T
RANSCEIVER
F
UNCTION
This message is used to set the standby COMM frequency.
Message format:
“V”.................Message class. This is a VHF NAV message.
“29”................Message identifier.
mk ..................Standby COMM frequency:
m = desired frequency in MHz in hexadecimal, where m = desired
frequency - 30h, with desired frequency in range of 118 to 136 MHz, or
162 MHz.
k = desired frequency in kHz, where k = (desired frequency / 25 kHz) +
30h, with desired frequency in range of 000 to 975 kHz in 25 kHz steps.
a......................Transceiver function: N = normal, M = monitor, 0 = unchanged.
Example message:
$PMRRV29G4M<chksm><CR><LF>
This example command would set the standby VOR frequency to 119.100 MHz. This is
interpreted by noting that the ASCII ‘G’ corresponds with 47h, +30h = 77h, converted to
decimal equals 119 for the MHz portion. The kHz portion converts ASCII ‘4’ to 34h, -30h yields
4h, x25 kHz steps = 100 kHz.
Note: The SL30 will check input frequencies for validity. An RS-232 serial error message output
will be generated if the frequency is invalid.
S
ET
A
CTIVE
COMM F
REQUENCY AND
T
RANSCEIVER
F
UNCTION
This message is used to set the Active COMM frequency as well as the COMM transceiver
function.
This message is only available in normal mode.
Message format:
“V”.................Message class. This is a VHF NAV message.