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5. OPERATION
5.6.2 Dog type home position return
A home position return method using a proximity dog. With deceleration started at the front end of the proximity
dog, the position where the first Z-phase signal is given past the rear end of the dog or a motion has been
made over the home position shift distance starting from the Z-phase signal is defined as a home position.
(1) Devices, parameters
Set the input devices and parameters as follows.
Item Device/Parameter used Description
Automatic/manual selection (RYn6) Turn RYn6 ON.
Manual home position return mode
selection
Point table No. selection 1 to 8
(RYnA to RYnE, RY(n
2)3 to RY(n 2)5)
RYnA to RYnE, RY(n
2)3 to RY(n 2)5
are turned off.
Remote register-based
position/speed setting
(Only when two stations are
occupied)
Position/speed specifying system selection
(RY(n
2)A)
Turn RY(n
2)A ON.
Dog type home position return Parameter No.PC02
0 :Dog type home position return is
selected.
Home position return direction Parameter No.PC03
Refer to section 5.6.1 (2) and choose home
position return direction.
Dog input polarity Parameter No.PD16
Refer to section 5.6.1 (2) and choose dog
input polarity.
Home position return speed Parameter No.PC04 Set speed until detection of dog.
Creep speed Parameter No.PC05 Set speed after detection of dog.
Home position shift distance Parameter No.PC06
Set when shifting the home position starting
at the first Z-phase signal after passage of
proximity dog rear end.
Home position return
acceleration/deceleration time
constants
Point table No.1
Use the acceleration/deceleration time
constants of point table No.1.
Home position return position data Parameter No.PC07
Set the current position at home position
return completion.
(2) Length of proximity dog
To ensure that the Z-phase signal of the servo motor is generated during detection of the proximity dog
(DOG), the proximity dog should have the length which satisfies formulas (5.1) and (5.2).
L
1
60
V
2
td
.............................................................................. (5.1)
L
1
: Proximity dog length [mm]
V : Home position return speed [mm/min]
td : Deceleration time [s]
L
2
2 S.................................................................................... (5.2)
L
2
: Proximity dog length [mm]
S : Moving distance per servo motor revolution [mm]