LG Electronics 120S user manual Backlash Compensation Amount, Bias Speed, Speed Limit

Chapter 7 Usage of Various Functions

(B)Backlash Compensation Amount

•The tolerance that the machine does not work by the wear when the rotation direction changes in case that a gear, screw etc is combined to run at the motor axle, is called as ‘Backlash”.

Therefore, when you change the rotation direction, it is required to add the backlash compensation amount to the positioning amount for output.

•The setting range is 0 ∼ 1,000(unit: Pulse) at each axis.

•If the position moved 1m to the right and again 1m to the left, it is not possible to reach the original position by backlash. At this time, it is required to add backlash compensation amount.

Gear	1m movement right side (normal)
		Direction change
	1m movement left side (reverse)
			Backlash
	Transfer amount including Backlash compensation amount

Backlash

(C)Bias Speed

•As the stepping motor has unstable torque near zero speed, the start speed shall be set in the beginning of operation in command to smooth the rotation of motor and reduce the positioning time. The speed to be set at this time is called “Bias Speed”.

•The setting range is 5∼10,000(unit: 1pps) at each axis.

•Bias speed shall be used for the main axis of

①positioning operation by setting command,

②origin return operation,

③ JOG operation.

	Speed
Bias speed	Positioning speed	Speed limit
setting action	Origin return speed	Bias speed not-setting
	JOG Speed
	Interpolation operation	action
	speed
Bias speed		Time

Acceleration	Deceleration
time		time

(D)Speed Limit

•max. Speed available to set for positioning operation.

•The setting range is 5~100,000 (unit : 1pps).

•The operation speed of positioning operation, origin return speed and Jog operation speed is influenced by speed limit and if they are set as higher value than speed limit, error will occur.

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