40
Frequency arrival output [FA1] uses the
standard output frequency (parameter
F001) as the threshold for switching. In
the figure to the right, Frequency Arrival
[FA1]
turns
ON
when
the
output
frequency gets within
Fon
Hz below or
Fon
Hz above the target constant
frequency, where
Fon
is 1% of the set
maximum frequency and
Foff
is 2% of the
set maximum frequency. This provides
hysteresis that prevents output chatter
near the threshold value. The hysteresis
effect causes the output to turn ON
slightly
early
as the speed approaches the
threshold. Then the turn-OFF point is
slightly
delayed
. Note the active low
nature of the signal, due to the open
collector output.
Frequency arrival output [FA2/FA4] works
the same way; it just uses two separate
thresholds as shown in the figure to the
right.
These
provide
for
separate
acceleration and deceleration thresholds
to provide more flexibility than for [FA1].
[FA2/FA4]
uses
/
during
acceleration for the ON threshold, and
/
during deceleration for the OFF
threshold. This signal also is active low.
Having
different
accel
and
decel
thresholds provides an asymmetrical
output function. However, you can use
equal ON and OFF thresholds, if desired.
As for [FA3/FA5] signal, the basic meaning
of “
Fon
/Foff”
is the same as above.
And, “
/
and
/
are
correlated with [FA2/FA4] signal.
Basically, the meaning of “
Fon/Foff
” in this
case is the same as above examples, but
there are slight differences from the usage
of [FA2/FA4] signal.
In acceleration status, [FA3/FA5] signal
becomes ON from ("
/
" - "
Fon
") to
("
/
" + "
Foff
").
In deceleration status, [FA3/FA5] signal
becomes ON from ("
/
" + "
Fon
") to
("
/
" - "
Foff
").
There is no [FA3/FA5] between "ONs" in
the figure, because frequency arrival
output is out of the area defined by the
sets of parameters.
FA1
signal
Output
freq.
Fon
Foff
Fon
ON
Foff
ON
0
Fon=1% of max. frequency
Foff=2% of max. frequency
FA2/FA4
signal
Output
freq.
thresholds
/
ON
0
/
Fon
Foff
Fon=1% of max. frequency
Foff=2% of max. frequency
FA3/FA5
signal
Output
freq.
thresholds
/
0
/
Fon
Foff
Fon=1% of max. frequency
Foff=2% of max. frequency
Foff
Fon
ON
ON
