Acceleration/deceleration pattern (Pr.29, Pr.140 to Pr.143)
You can set the acceleration/deceleration pattern suitable for application.
You can also set the backlash measures that stop acceleration/deceleration once at the parameter-set
frequency and time during acceleration/deceleration.
Backlash acceleration stopping frequency
Backlash acceleration stopping time
Backlash deceleration stopping frequency
Backlash deceleration stopping time
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 173)
Setting value "0"
Setting value "1"
As the acceleration/deceleration time of S-pattern acceleration/deceleration A, set the time taken until Pr. 3 Base frequency
is reached, not Pr. 20 Acceleration/deceleration reference frequency.
Setting value "2"
Setting value "3"
(1) Linear acceleration/ deceleration (Pr. 29 = "0", initial value)
When the frequency is changed for acceleration, deceleration, etc. in inverter
operation, the output frequency is changed linearly (linear acceleration/
deceleration) to reach the set frequency without straining the motor and
inverter. Linear acceleration/deceleration has a uniform frequency/time slope.
(2) S-pattern acceleration/deceleration A (Pr. 29 = "1")
For machine tool spindle applications, etc.
Used when acceleration/deceleration must be made in a short time to a high-
speed range of not lower than the base frequency. In this acceleration/
deceleration pattern, Pr. 3 Base frequency (fb) is the inflection point of the S
pattern and you can set the acceleration/deceleration time appropriate for motor
torque reduction in a constant-power operation range of base frequency (fb) or
(3) S-pattern acceleration/deceleration B (Pr. 29 = "2")
For prevention of load shifting in conveyor and other applications. Since
acceleration/deceleration is always made in an S shape from current
frequency (f2) to target frequency (f1), this function eases shock produced
at acceleration/deceleration and is effective for load collapse prevention,
(4) Backlash measures (Pr. 29 = "3", Pr. 140 to Pr. 143)
What is backlash?
Reduction gears have an engagement gap and have a dead zone between
forward rotation and reverse rotation. This dead zone is called backlash, and
this gap disables a mechanical system from following motor rotation.
More specifically, a motor shaft develops excessive torque when the
direction of rotation changes or when constant-speed operation shifts to
deceleration, resulting in a sudden motor current increase or regenerative
To avoid backlash, acceleration/deceleration is temporarily stopped.
Set the acceleration/deceleration stopping frequency and time in Pr. 140 to
Setting of acceleration/deceleration time
and acceleration/deceleration pattern
Linear acceleration/ deceleration
S-pattern acceleration/deceleration A
S-pattern acceleration/deceleration B
0 to 400Hz
Set the stopping frequency and time
0 to 360s
for backlash measures.
0 to 400Hz
Valid when Pr. 29 = 3
0 to 360s