Override (Speed); Deviation Counter (Speed); Feedback Pulse; Sigmoid Acceleration/Deceleration - Fuji Electric micrex-sx SPH User Manual

(7) Override (speed)

• Override is the function to change the speed for
positioning by external command.

(8) Deviation counter (speed)

• Deviation counter is the up/down counter which counts the difference between the command pulse and feedback
pulse.

(9) Feedback pulse

• Feedback pulse is indicated by the encoder feedback pulse which becomes the information on the actual moving
length and speed of motor.

(10) Sigmoid acceleration/deceleration

• Sigmoid acceleration/deceleration is the method to use a sigmoid curve for approximating the locus of movement
while the motor is accelerated or decelerated.
By sigmoid acceleration/declaration, it is possible to lower the shock acting on the mechanical system while the
motor is accelerated and thus achieve smooth acceleration/deceleration.

(11) Servo lock

• When the motor is stopped, an external force may act, resulting in displaced stop position. In such cases, the
displacement is detected and control is immediately taken to electrically restore to the original position (torque is
generated here). This appears as if the machine is being locked. This condition is called "servo lock."

(12) Over-travel

• Over-travel is the movement exceeding the reference operating range.
For positioning operation, in general, left and right (±) limit switches are set to prevent over-travel. (The limit
switches are connected to the +OT and -OT terminals of the positioning control module.)

(13) Marker signal

• Marker signal is an encoder phase-Z signal (1 pulse/rev.) and is used as the reference signal for original-point
return.
Appendix-5 Terminology
App.-13