Tritech MicronNav - NMEA $GPDBT

Using the External Computer Data Link MicronNav System
0656-SOM-00001-07 125 © Tritech International Ltd.
7.2.11. NMEA $GPDBT
This NMEA string format is used for Water Depth data output and is the Depth Below
Transducer value that is mainly sent by positioning devices. It provides the Z (Depth) co-
ordinate output position in the USBL system.
The full string format is as follows:
‘$GPDBT’ Reply Data Structure
Data Description Data Range Field Range
NMEA string header Always ‘$GPDBT’ hhhhhh
Comma separator Always ‘,’ ,
Depth in units of Feet 0 to 999999 f.ff
Comma separator Always ‘,’ ,
Units Identifier Always 'f' U
Comma separator Always ‘,’ ,
Depth in units of Metres 0 to 999999 M.MM
Comma separator Always ‘,’ ,
Units Identifier Always 'M' U
Comma separator Always ‘,’ ,
Depth in units of Fathoms 0 to 999999 F.FF
Comma separator Always ‘,’ ,
Units Identifier Always 'F' U
Delimiter (asterisk) Always ‘*’ *
Checksum (in Hexadecimal)
(XOR of bytes between, but not inclusive
of, '$' and '*')
00 to FF cc
(Carriage Return + Line Feed) N/A <CR><LF>
Example:
Z (Depth) value = 54.12 metres.
ASCII Output Always = “$GPDBT,177.55,f,54.12,M,29.59,F*32<CR><LF>”
Where; “<CR>” is Carriage Return (ASCII code 13), “<LF>” is Line Feed (ASCII code 10).