- 33 -
Gyropilot Graphic user guide
– 33-60-025-003 rev3
2.12 NMEA LINK
The
Gyropilot Graphic
includes an NMEA input, allowing the connection of a GPS or any other
instrument providing NMEA frames : PC, meteorological sensors, etc. After performing the
NMEA initialization of the
Gyropilot Graphic
, the NMEA channels corresponding to the frames
transmitted by the instrument are available on the
TOPLINE bus
. You can then display data.
Please note that if an instrument transmits an NMEA frame which is already created by an
nke
sensor, then this frame will not be taken into account.
2.12.1 Connection of the NMEA link
The NMEA input of the
Gyropilot Graphic
only allows the connection of one instrument
providing NMEA frames (see installation chapter). If you wish to connect a second instrument
(for example a GPS and a PC), you must connect it either to the NMEA input of another display
or to a
TOPLINE NMEA INPUT INTERFACE
(ref: 90-60-055).
2.12.2 Initialization procedure for the NMEA bus
Using the
Page
key,
select the
Main menu
page,
then using the browser, select
Configuration
the
NMEA initialisation
,
press the
Ent
key and follow the instructions displayed,
The
Gyropilot Graphic
subsequently performs a sequence of NMEA data search for 20
seconds, then it creates the new channels corresponding to the NMEA frames transmitted by
the instrument. The NMEA channels created are saved in the display memory and restored
every time it is powered up.
2.12.3 Frames identified by the
Gyropilot Graphic
The NMEA frames identified by the
Gyropilot Graphic
are in conformity with the NMEA
standard 0183 V2.30 (or lower version).
The NMEA input is insulated by an optocoupler.
The format of the frames is: 4,800 bauds / 8 bits with bit 7 at 0 / 1 start bit and 1 stop bit.
Distances are truncated to the lower value and the other dimensions are rounded to the nearest
unit (ex: degrees for angles).
A frame can be partially empty between the commas.
The
Gyropilot Graphic
will take the missing data in another frame (ex: speedo in VWH and
compass in HDG). The depth in feet will be identified if it does not exist in meters for example. A
channel can be included in several frames (ex: the compass is taken in HDG in priority, if not in
HDM, if not in VHW). If the COG or the WP heading do not exist in magnetic, the true heading
is taken.
Refreshing of the display of the NMEA channels is performed each time a new valid NMEA
frame is received. If the NMEA link is lost (example: loss of satellites on the GPS) the last
received data will remain on the display for 64 seconds. After that, the
Gyropilot Graphic
will
signal the breakdown.
