Omron 3G3MX2 User Manual page 256

Using Intelligent Output Terminals
230
Frequency arrival output [FA1] uses
the standard output
(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 decelera-
tion thresholds to provide more flexi-
bility than for [FA1]. [FA2/FA4] uses
C042/C045 during acceleration for the

ON threshold, and
deceleration for the OFF threshold.
This signal also is active low. Having
different accel and decel thresholds
provides an asymmetrical output func-
tion. However, you can use equal ON
and OFF thresholds, if desired.
Frequency arrival output [FA3/FA5]
works also the same way, only differ-
ence is arriving at set frequency.
Output
freq.
frequency
0
FA1
signal
Fon = 1% of max. frequency
Foff = 2% of max. frequency
Output
freq.
thresholds
C042 C045 /
C043 C046 /
0
FA2/FA4
 signal
/ during
Output
freq.
thresholds
C042 C045 /
C043 C046 /
0
FA3/FA5
signal
Section 4-6
Foff
Fon F001
F001
Foff
Fon
ON ON
Fon
Foff
ON
Fon = 1% of max. frequency
Foff = 2% of max. frequency
Foff
Fon
Fon
Foff
ON ON
Fon = 1% of max. frequency
Foff = 2% of max. frequency