15. PMC CONTROL FUNCTION
B–63503EN–1/01
732
(a) The speed command for PMC axis control requires specification
of the servo motor speed, not the feedrate along an axis. To
specify a feedrate along the axis when gears are used to link the
servo motor and axis, the feedrate must be converted to a rotation
speed of the servo motor speed. As the motor speed must be
specified with an integer, the converted speed is subject to a
round–off error.
(b) The minimum increment for specifying the motor speed is
calculated by the following formula and rounded to the nearest
integer:
Fmin +
P 2
15
1
1000
Fmin : Minimum increment
for the motor speed
P : Number of pulses per
rotation of the detector
for velocity feedback
Specify the speed command using the value calculated by the
following formula:
F +
N P 2
15
1
1000
F : Speed command value
(integer)
N : Servo motor speed
(min
–1
)
P : Number of detector
pulses issued per rotation
for velocity feedback
NOTE
In speed command mode, the speed after
acceleration/deceleration is specified to the servo control
unit. The loop gain for position control is invalid.
(16) When a torque control command (EC0g to EC6g: 11h) is specified
Specify the maximum speed in torque control mode, in rpm.
A servo alarm (No. 422) is issued if there is no object for which a
torque is to be generated or if the feedrate exceeds the specified value
while torque control is being applied.
The maximum feedrate in torque control mode can be changed in
torque control mode by setting the new feedrate data in the signal
then inverting the logic of axis control command read signal
EBUFg.
Valid data range Units
1 to 32767 min
–1