Fuji Electric FRENIC-VG Series - Page 117

6.2 PG Interface Expansion Card
6-41
Chap. 6
CONTROL OPTIONS
The following equation describes the relationship between the F/F gain and the APR gain:
frequency)(input
G
|G1|
|deviation state-Steady|
APR
FF
××
−
= α
GFF: F/F gain, GAPR: APR gain,
α: Input format constant (α = 4 if 90° phase difference; otherwise, α = 1)
(6) Deviation overrun alarm width (o18)
A deviation overrun occurs when the
difference between the internal
command position and the actual
amount of motor rotation (i.e., the
deviation) is equal to or greater than
this setting, causing the motor to
perform a free-run stop. The keypad
LED will display "
d0 ," and the LCD
will display alarm information related
to the deviation overrun.
Deviation overrun alarms can be canceled by turning off the position control [SYC] and inputting the
[RST] signal (see Figure 6.2.36).
Deviation overruns occur when the
motor fails to track position
commands. Although the initial value
(factory setting) is 65,535 pulses
(internally the setting is multiplied by
10), it should be set to about 2 times
the position deviation that occurs
during normal operation. If the
function code APR gain and F/F gain
settings have not been configured with
optimal values, the motor may exhibit
hunting behavior.
If that occurs, this value must be set again so that a deviation overrun alarm occurs immediately and the
motor performs a free-run stop. Note that using a setting that is too low may cause the alarm to be
triggered during acceleration and deceleration.
(7) Deviation zero width (o19)
The synchronization control complete
signal is output when the motor's
current position falls within the range
defined by this setting from the target
position. This functionality allows
detection of the fact that the motor has
almost reached the target position. The
magnitude of this setting does not
affect the positioning system. The
synchronization control complete
signal is assigned by allocating 27
[SY-C] to an output selected with the
Y1 to Y5 functions.
Figure 6.2.37 illustrates the [SY-C] output state when the value 20 is allocated to the deviation zero
width.
Deviation
overrun
-655350 +655350
ON
OFF
0
Amount of
deviation
[pulses]
[SYC]
[FWD]
[RST]
Deviation
overrun
ON
OFF
ON
OFF
ON
OFF
Zero
deviation
-20 +20
ON
OFF
0
Amount of
deviation
[pulses]
Figure 6.2.36
Figure 6.2.37
Figure 6.2.35