GRAUPNER JetCat 6810, Руководство пользователя

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69
The ECU fail-safe system
The ECU features its own fail-safe circuit, independent of the radio control system, i.e. if the
signal from the transmitter fails or suffers interference, an automatic process is triggered in
response.
Failure of the “THR” channel signal or reception of a pulse width outside the permissible
range
both constitute “interference”.
If interference of this type is detected, the ECU initially maintains the current rotational speed for
the period(s) set in the “FailSafeDly” parameter (LIMITS menu). After this it reduces turbine
speed to the value set in the “FailSafeRPM” parameter (normally “idle”), until such time as the
interference finishes, or until the period(s) defined in the “FailSafeTimeOut” parameter has
elapsed; in the latter case, the ECU switches off the turbine.
The following points must therefore be noted:
The transmitter must be programmed in such a way that the “THR” channel signal never
exceeds or falls below the learned-in range in normal operations.
If you are using a PCM radio control system (with its own fail-safe functionality), the two fail-safe
systems (ECU and PCM receiver) inter-act, and this must be considered when setting up the
radio control system:
•
If the radio control system is programmed in the recommended way (fail-safe -> idle), it is
impossible for the ECU to detect interference, because the channel signal is always
present (the PCM receiver generates the signal automatically if interference occurs); for the
same reason the signal always stays within the prescribed range. In this situation fail-safe
is handled exclusively by the radio control system itself.
•
If you wish to use the ECU’s integral fail-safe function, then you must deliberately program
a value for the fail-safe position of the “THR” channel which lies outside the learned-in
range. If you do this, an invalid signal will be passed to the ECU when the receiver picks up
interference, and the ECU’s fail-safe circuit will then respond in the manner already
described.
The fail-safe parameters should therefore be set as follows:
FailSafeDly (HOLD)
The time for which the current turbine speed is maintained (recommended: approx. 1
second). This means that very short interference is effectively suppressed.
FailSafeRPM
The rotational speed to which the turbine is reduced after the FailSafeDly period has
elapsed (recommended: 33,000).
FailSafeTimeOut
The time after which the turbine is switched off if persistent interference occurs
(recommended: 20 seconds).