Simrad Autopilot AP26 - Manual (Page 104)

Simrad AP26 and AP27 Autopilots
102
20221586B
Depth Offset
Note ! This adjustment only applies to “smart” depth transducers that
outputs depth on NMEA2000 format. NMEA0183 sentence
‘DPT’ contains offset and the depth reading is from the surface.
NMEA0183 sentence ‘DBT’ contains no depth offset and the
reading will be from the position of the transducer.
When the depth offset is set to
zero, the indicated depth is
from the transducer to the
bottom.
To read the depth from the water surface to the bottom you have
to set the depth offset according to the vertical distance between
the surface and the transducer, i.e. positive (+) value. If you want
to indicate the depth from the keel to the bottom you have to set
the depth offset according to the vertical distance between the
transducer and the keel, i.e. negative (–) value.
Automatic tuning
Automatic tuning is a feature that automatically sets the two
main steering parameters (Rudder and Counter Rudder) by
taking the boat through a number of S-turns. The scaling factors
of the parameters are also set automatically as a function of the
boat type selection performed in the Dockside menu.
Automatic tuning is an optional procedure that is not required for
the autopilot to function. The autopilot is preset with steering
parameters that should steer most boats in the 30 - 80 foot range.
It is, however, recommended to perform an automatic turning as
part of the sea trial.
Recommended speed during Automatic tuning varies with the
type of boat, but should not exceed 10 knots.
Note ! Automatic tuning should not be performed at planing speed!
For displacement boats use a speed that is approximately half the
normal cruising speed (i.e. if cruising speed is 10 knots, perform
the Automatic tuning at about 5 knots).
The parameter values calculated during Automatic tuning
becomes the HI parameters. The LO parameters are
automatically set to 66% of the HI.