Garmin NavComm SL30, Installation Manual, Page: 74 / 88

Serial Interface Specifications
66 Apollo SL30 Installation Manual
R
EQUEST
D
ATA
O
UTPUT
This input is used to request an output message to be sent by the SL30.
Message format:
“V”.................Message class. This is a VHF NAV message.
“24”................Message identifier.
ii .....................Output identifier of requested message, two ASCII characters.
dd ...................Message data, two encoded hex
3
characters (30h-3Fh), used for specific
output request. Set to “00” if not needed. These characters are used for
such items as selecting a specific EEPROM address to output.
a......................Request type: (ASCII) “0” = output once; “L” = output repeatedly at low
speed (1 Hz); “H” = output repeatedly at high speed (10 Hz).
Table 5 - Data Output Requests
ii Output Dd Data Description a
“20” Reset Status “00” “0”,
“21” CDI, GSI, and Flags “00” “0”, “L”, “H”
“22” Decoded OBS Setting “00” “0”, “L”, “H”
“23” Radial from Active VOR “00” “0”, “L”, “H”
“24” Radial from Standby VOR “00” “0”, “L”
“25” Decoded Station Identifier “00” “0”, “L”
“28” Receiver Status “00” “0”
“29” NAV Audio Mode “00” “0”
“30” NAV Microcontroller
Software Version
“00” “0”
“31” NAV DSP Software
Version
“00” “0”
“32” ADC Data Output cc ADC channel: “00” to “08” “0”
“35” Comm Transceiver Status “00” “0”
“36” Comm Software Version “00” “0”
Example messages:
$PMRRV242100L<chksm><CR><LF>
Request periodic output of CDI, GSI, and related flags at low (1 Hz) rate.
$PMRRV2432050<chksm><CR><LF>
Request a single output of ADC data from channel 5.
3
Encoded hex: each character consists of 4 bits of data placed in the low order 30h. For example, the 8-bit
value 5Fh would be encoded as two characters with values of 35h and 3Fh, which map to the ASCII characters “5”
and “?”, respectively.