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Note: starting from DST4602x version 00.48, it is possible to use another digital input to
decide if using the analogue input or the parameter P.0974 to set the “no-load
frequency”. That input will be configured with the DIF.2714 function. The possibilities
are:

o
If no analogue input is configured with the AIF.2304 or AIF.2305 function, the set
point is established by the parameter P.0974.
o
If there is an analogue input configured with the AIF.2304 or AIF.2305 function:

The set point is established by the analogue input if there are no digital input
configured with the function DIF.2714.

The set point is established by the analogue input if there is at least one
digital input configured with the function DIF.2714.

The set point is established by the parameter P.0974 if all the digital inputs
configured with the DIF.2714 function are in stand-by.
GC400x.
Configure the analogue input with AIF.2305 function. In this way, the conversion of the
value acquired by the analogue input in "no-load frequency" is performed by a
conversion curve (see technical manual). It is possible to use another digital input to
decide if using the analogue input or the parameter P.0974 to set the "no-load
frequency". That input will be configured with the function DIF.2714. The possibilities
are:

o
If no analogue input is configured with the AIF.2305 function, the set point is
established by the parameter P.0974.
o
If there is an analogue input configured with the AIF.2305 function:

The set point is established by the analogue input if there are no digital input
configured with the function DIF.2714.

The set point is established by the analogue input if there is at least one
digital input configured with the function DIF.2714.

The set point is established by the parameter P.0974 if all the digital inputs
configured with the DIF.2714 function are in stand-by.
GC500x.
o
Obsolete It is necessary to select an analogue input through P.0971 parameter (any
value other than "0" and "7"). In this case, there is no need to configure anything in
the parameters related to the selected analogue input, and P.0972 and P.0973
parameters are used for scaling the analogue input. See description above for
DST4602x.
o
Suggested. Setting the value "7" in P.0971 parameter. In this case it is necessary
to configure the analogue input with the desired AIF.2305 function (see description
above for DST4602x).
GCU allows setting the slope of the frequency DROOP curve via P.0975 parameter (%/Hz). It
indicates which percentage of the generator rated power (P.0125) corresponds to a decrease of 1
Hz of working frequency. The image above shows a curve for the DROOP allowing a total range of
4 Hz passing from 0% through 100% of the generator power: the value for P.0975 parameter to
configure the previous curve would be 25 %/Hz.
As mentioned above, working with DROOP means imposing a working frequency according to the
present load. Since GCU interfaces with a rpm regulator (whose job is to ensure that the engine
works at the speed required externally), in principle it is not necessary to use a PI regulator on GCU:
it is enough to calculate the number of rounds corresponding to the present load and request it to
the rpm regulator. This is especially true for electronic engines (Can Bus), where GCU is able to
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