Mitsubishi Electronics Q172HCPU, Q173HCPU 6 POSITIONING CONTROL, 6.23Home Position Return

6 POSITIONING CONTROL

6.23Home Position Return

(1)Use the home position return at the power supply ON and other times where confirmation of axis is at the machine home position is required.

(2)The following six methods for home position return are shown below.

•Proximity dog type

•Count type

•Data set type

•Dog cradle type

•Stopper type

•Limit switch combined type

(3)The home position return data must be set for each axis to execute the home position return.

(4)Select the optimal home position return method for the system configuration and applications with reference to the following.

Home position return methods			Contents	Applications
			• Home position is zero point of servomotor.	• It is used in the system which can surely pass a
	Proximity dog type 1		• When the proximity dog is ON, it cannot be	zero point from the home position return start to
Proximity dog type			started.	proximity dog ON	OFF.
	Proximity dog type 2		• Home position is zero point of servomotor.	• This method is valid when the stroke range is
			• When the proximity dog is ON, it can be	short and "proximity dog type 1" cannot be used.
			started.
			• Home position is zero point of servomotor.	• It is used in the system which can surely pass a
	Count type 1			zero point from the home position return start to
				point of travel distance set as "travel value after
Count type (Note)				proximity dog ON".
			• Zero point is not used in the home position	• This method is used when the proximity dog is
	Count type 2		return.	near the stroke end and the stroke range is
				narrow.
	Count type 3		• Home position is zero point of servomotor.	• This method is valid when the stroke range is
				short and "count type 1" cannot be used.
			• Home position is command position of	• External input signals such as dog signal are not
	Data set type 1		Motion CPU.	set in the absolute position system.
Data set type				• This method is valid for the data set independent
				of a deviation counter value.
	Data set type 2		• Home position is real position of	• External input signals such as dog signal are not
			servomotor.	set in the absolute position system.
			• Home position is zero point of servomotor	• It is easy to set the position of proximity dog,
Dog cradle type			immediately after the proximity dog signal	because the proximity dog is set near the
			ON.	position made to the home position.
			• Home position is position which stopped	• This method is valid to improve home position
		Stopper type 1	the machine by the stopper.	accuracy in order to make the home position for
Stopper type			• Proximity dog is used.	the position which stopped the machine by the
		Stopper type 2	• Home position is position which stopped	stopper.
			the machine by the stopper.
			• Proximity dog is not used.
			• Home position is zero point of servomotor.	• It is used in the system that the proximity dog
Limit switch combined type			• Proximity dog is not used.	signal cannot be used and only external limit
			• External limit switch is surely used.	switch can be used.

(Note): If the proximity dog signal of servo amplifier is used, the count type home position return cannot be execute.

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