V A L A V I O N I C S L T D
N A V 2 0 0 0 N A V I G A T I O N S Y S T E M
I N S T A L L A T I O N A N D O P E R A T O R ’ S M A N U A L
Pre-Release Issue
Page 26 of 29
Sept. 2013
N
AVIGATION
V
OLUME CONTROL
This message is used to adjust the volume level of the NAV unit
Message format:
"V" ..................... Message class - VHF NAV Message
"73" .................... Message Identifier
"v" ...................... Volume level:
v = Desired volume level in encoded hexadecimal, where v =
desired level + 0x30 with a range between 0 - 20, 0 being
muted
Example Message:
$PMRRV73;<chksum><CR><LF>
This example command would set the volume level at 11.
OUTPUT MESSAGES
RESET STATUS
This message is sent to indicate to the host that the NAV 2000 is running and ready to accept data
on the serial port. It will be sent once upon startup and when requested by the host.
Message format:
“V”………..Message class. This is a VHF NAV message.\
“20”………Message identifier.
Example message:
$PMRRV20<chksm><CR><LF>
NAV 2000 is running and ready to accept serial input.
CDI, GSI, AND RELATED FLAGS
This message outputs the current values of the CDI, GSI, and their related flags. After power up
this message will be output at a 10 Hz rate.
Message format:
“V” ..................... Message class. This is a VHF NAV message.
“21”.................... Message identifier.
cc........................ CDI deflection. An eight-bit value indicating the amount of deflection
of the CDI needle, represented as two encoded hex
3
digits. The CDI
deflection is a twos complements signed integer in the range of –100 to
100. –100 indicates full left deflection, 0 indicates no deflection, and
100 indicates full right deflection.
gg ....................... GSI deflection. An eight-bit value indicating the amount of deflection
of the GSI needle, represented as two encoded hex
3
digits. The CDI
deflection is a twos complement signed integer in the range of –100 to
3
Encoded Hex: each character consists of 4 bits of data placed in the low order 30h. For example,
the 8-bit value of 5Fh would be encoded as two characters with values of 35h and 3Fh, which map to the
ASCII characters “5” and “?” respectively.
