Hitachi L300P Series Instruction Manual page 172

4–38
Using Intelligent Output Terminals
Frequency arrival output [FA1] uses the
standard output frequency (parameter F001)
as the threshold for switching. In the figure
to the right, the inverter accelerates to the
set output frequency, which serves as the
threshold for [FA1]. Parameters F
illustrate the hysteresis that prevents output
chatter near the threshold value.
• F is 1% of the max. output frequency
on
• F is 2% of the max. output frequency
off
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. The 1% and
2% values also apply to the remaining
Frequency arrival outputs, discussed below.
Frequency Arrival output [FA2] uses two
separate thresholds as shown in the
figure. These provide for separate accel-
eration and deceleration thresholds to
provide more flexibility than for [FA1].
[FA2] uses C042 and C043 for ON and
OFF thresholds, respectively. Having
different accel and decel thresholds
provides an asymmetrical output
function. However, you can use equal
ON and OFF thresholds, if desired.
Frequency Arrival output [FA3] uses the
same threshold parameters as [FA2]
above, but it operates in a slightly differ-
ent way. Refer to the diagram below. After the frequency arrives at the first threshold during
acceleration and turns ON [FA3], it turn OFF again as the output frequency accelerates further.
The second thresholds work similarly during deceleration. In this way, we have separate ON/
OFF pulses for acceleration and deceleration.
Output
frequency
Hz
Thresholds
C043
F
on
C042
0
FA3
Output
frequency
Hz
F
Threshold
and F
on off
F001
0
FA1
Output
frequency
Hz
F
Thresholds
C042
C043
0
FA2
F
F
off
F
on off
on
F
F
off
on
t
off
t
t