
B–64113EN–1/01
7. FEEDRATE CONTROL/ACCELERATION
AND DECELERATION CONTROL
403
A specified cutting feedrate can be linearly increased or decreased before
interpolation. This function eliminates machining profile errors caused
by the delay occurring in acceleration or deceleration. The time required
for acceleration or deceleration by this function is significantly shorter
than that by the function of exponential acceleration/deceleration.
CNC command
Servo control
Servo motor
Feedrate
Speed
Time
F
F
Feedrate
command
Move data
F: Value of feedrate command
Pulse
distribution
(interpolation)
Servo control
Linear accel-
eration/decel-
eration before
interpolation
The function of linear acceleration/deceleration before interpolation in-
creases or decreases the feedrate specified in the tangential direction.
If the feedrate command is changed
D Type A
Acceleration/deceleration is started in the block in which a new feedrate
command is specified.
D Type B (Set the FWB bit (bit 0 of parameter No. 1602) to 1.)
Deceleration: Deceleration is started in a prior block such that decelera-
tion is completed before the beginning of the block in
which a new feedrate command is specified.
Acceleration: Acceleration is started in the block in which a new fee-
drate command is specified.
B type
A type
<Deceleration Example> <Acceleration Exapmle>
Command feedrate
Feedrate after accel-
eration/deceleration
before interpolation
Command feedrate
Feedrate after accel-
eration/deceleration
before interpolation
Feedrate
Point P
Time
F3
F2
F1
N1 N2
Feedrate
Time
F3
F2
F1
N1 N2
With B type, to decelerate from F3 to F2,
deceleration must start with point P.
Linear Acceleration/
Deceleration before
Cutting Feed
Interpolation