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6.5 Speed Control
6.5.2 Soft Start Settings
6-22
6.5.2
Soft Start Settings
The soft start function takes a stepwise speed reference input and applies the specified accel-
eration/deceleration rates to convert it to a trapezoidal speed reference.
You specify the acceleration/deceleration rates in Pn305 (Soft Start Acceleration Time) and
Pn306 (Soft Start Deceleration Time).
Use this function to perform smoother speed control (including internal set speed control).
Pn305: The time required for the Servomotor to accelerate from a stopped state to the maxi-
mum motor speed.
Pn306: The time required for the Servomotor to decelerate from the maximum motor speed to
a stopped state.
You can calculate the actual acceleration/deceleration times with the following formulas.
Pn305
Soft Start Acceleration Time
Setting Range
Setting Unit
Default Setting
When Enabled
Classification
0 to 10,000
1 ms
0
Immediately
Setup
Pn306
Soft Start Deceleration Time
Setting Range
Setting Unit
Default Setting
When Enabled
Classification
0 to 10,000
1 ms
0
Immediately
Setup
When Enabled
Meaning
Analog
Speed
Speed
Pn
3
05
Pn
3
06
Actual
deceleration
time
Actual
acceleration
time
Target
s
peed
Maximum
s
peed
Maximum
s
peed
Target
s
peed
×
S
oft
s
tart deceleration time (Pn
3
06)
Actual deceleration time =
×
S
oft
s
tart acceleration time (Pn
3
05)
Maximum
s
peed
Target
s
peed
Actual acceleration time =
Analog