Mitsubishi Electric MR-JE-C, Instruction Manual

Page: 238 / 312

12. WHEN USING WITH A GENERAL-PURPOSE INTERFACE
12 - 23
12.4.2 Dog type homing
This is a homing type using a proximity dog. Deceleration starts at the front end of the proximity dog. After
the rear end is passed, the position specified by the first Z-phase signal, or the position of the first Z-phase
signal shifted by the specified home position shift distance is used as the home position.
(1) Device/parameter
Set input devices and parameters as follows:
Item Device/parameter to be used Setting
Homing mode selection MD0 (Operation mode selection 1) Switch on MD0.
DI0 (Point table No. selection 1) to DI7 (Point
table No. selection 8) Switch off DI0 to DI7.
Home position return
direction [Pr. PT45 Home position return types] Select the homing direction with [Pr. PT45]. The
setting is shown as follows:
Address increasing direction: -1
Address decreasing direction: -33
Dog input polarity [Pr. PT29 Function selection T-3] Refer to section 12.4.1 (2) (b) to select the proximity
dog input polarity.
Home position return speed [Pr. PT05 Home position return speed] Set the rotation speed until a dog is detected.
Creep speed [Pr. PT06 Creep speed] Set the rotation speed after a dog is detected.
Home position shift distance [Pr. PT07 Home position shift distance], [Pr.
PT57 Home position shift distance (extension
parameter)] Set these parameters when shifting the home position
from the first Z-phase signal after the rear end of the
proximity dog is passed.
Acceleration time
constant/deceleration time
constant of homing [Pr. PT61 Home position return acceleration
time constant] or [Pr. PT62 Home position
return deceleration time constant] The acceleration/deceleration time constant of [Pr.
PT61] or [Pr. PT62] is used.
Set [Pr. PT60 Function selection T-8] to select the
parameters to be used.
Homing position data [Pr. PT08 Home position return position data],
[Pr. PT58 Home position return position data
(extension parameter)] Set the current position at the time of homing
completion.
(2) Length of the proximity dog
Set the length of the proximity dog to satisfy the equations (12.1) and (12.2) so that the Z-phase signal
of the servo motor is generated during the detection of DOG (proximity dog).
L
1
≥
V
60 •
td
2 ·············································································································· (12.1)
L
1
: Length of the proximity dog [mm]
V: Homing speed [mm/min]
td: Deceleration time [s]
L
2
≥
2 • ΔS ·················································································································· (12.2)
L
2
: Length of the proximity dog [mm]
ΔS: Travel distance per servo motor revolution [mm]