Furuno SC-50 Operator's Manual page 75

VLW - Distance travelled through the water
The distance travelled, relative to the water.
$--VLW,x.x,N,x.x,N*hh<CR><LF>
| | | | |
| | | | +--------- 3
| | +---+----------- 2
+---+----------------- 1
1. Total cumulative distance, nautical miles
2. Distance since reset, nautical miles
3. Checksum
VTG - Course over ground and ground speed
COG and SOG obtained by processing the GPS signals.
$GPVTG, x.x, T, x.x, M, x.x, N, x.x, K, p*hh<CR><LF>
Course degrees magnetic
Course degrees true
*A = Autonomous, D = Differential, E = estimated(dead reckoning), M = Manual input, S = Simulator,
N = Data not valid. The Mode indicator field supplements the Status field. The Status field shall be
set to V=invalid for all values of Operating Mode except for A=Autonomous and D=Differential. The
positioning system Mode indicator and Status field shall not be null fields.
Note: Position system indicator with IEC ED2 only.
ZDA - Time and date
UTC, day, month, year and local time zone.
$GPZDA. hhmmss.ss, xx, xx, xxxx, xx, xx*hh<CR><LF>
UTC (See NOTE2)
NOTE1 - Zone description if the number of whole hours added to local time to obtain GMT. Zone
description is negative for east longitudes.
NOTE2 – Decimal point and decimal fraction are not output.
Positioning mode indicator*
Speed, km/h
Speed, knots
Local zone minutes description, same sign as local hours
Local zone description 00 h to ± 13 h (See NOTE1)
Year
Month, 01 to 12
Day, 01 to 31
APPENDIX
AP-7