Operation Manual

Storage of Fail Safe data; only in PCM mode
(access via Set-Up Menu)
Helicopter 83
Receiver Battery
FAIL SAFE
FAIL SAFE MEMORY and
This function is only possible when in PCM mode
and with receiver models mc-12, mc-18, mc-20 and
DS 20 mc!
FAIL SAFE MEMORY
The higher working reliability of Pulse Code
Modulation (PCM) in relation to the simple Pulse
Position Modulation (PPM) results from the fact that
the microprocessor built in the receiver recognizes,
whether a received control signal was falsified or
damaged by external interference. In these cases
the receiver automatically replaces this disturbed
signal by the last correctly received, which was
stored in the receiver just in case. In this way brief
interference, where the radio signal is weak or the
like, is managed which would otherwise lead to the
well-known "glitching".
When a longer lasting disturbance to the
transmission between transmitters and receivers
occurs, the mc-16/20 software offers two different
options of FAIL SAFE programming. Using the
INC / DEC keys, the "FST" (Fail Safe Time) can be
selected:
1. HOLD program (display "HO")
:
In this case the Servos stops, in the case of a
transmission disturbance to the receiver, in the
position set by the last intact control signal. It
remains in that position until a new, recognizable,
control signal is detected by the receiver.
2. Variable programmable fail-safe with delay option
(display: 0.3, 0.5 or 1.0):
The servo moves to a pre-programmed set
position, until the receiver receives an intact
control signal. It is possible to set a delay time
from the beginning of the interference to the
operation of the fail safe program. This is settable
in three steps (0.3s, 0.5s and 1.0s using the
INC/DEC keys, taking into account different
model speeds.
The desired positions of the servos on control
functions 1 to 8, during the operation of fail safe, are
simultaneously set at the transmitter and then the
CLEAR key is pressed. These momentary positions
are stored now as the fail safe positions. During
operation these values are transferred to the
receiver’s memory, so that the receiver can fall back
to them during interference. Storing is confirmed, in
the display, by the brief display of "FSM EN", (Fail
Safe Memory Entered). The fail-safe servo positions
can be reset at any time, even in flight, by selecting
the code and pressing CLEAR to be overwrite the
existing settings.
This function is only possible when in PCM mode
and with receiver models mc-12, mc-18, mc-20 and
DS 20 mc!
Receiver Battery FAIL SAFE
The output channel for the Receiver Battery FAIL
SAFE is preset for model types "FL" and "AC" on
channel 1 (throttle/spoiler), and for the types "UN",
"Fb", "HE" on the channel 8.
As soon as the voltage of the receiver battery falls
below a certain value, the associated servo goes to
it’s central position, to indicate the low battery
voltage. By movement of control stick (1 or 8) the
FAIL SAFE servo is release, so that servo again
operates as desired by the pilot. The model must be
landed immediately after the first FAIL SAFE
message.