Mitsubishi Electric MR-JE-C Instruction Manual Download Page 252

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12. WHEN USING WITH A GENERAL-PURPOSE INTERFACE

12 - 37

12.4.10 Count type front end reference home position return

POINT

This homing type depends on the timing of reading DOG (Proximity dog) that
has detected the front end of the proximity dog. Therefore, when a homing is
performed at a creep speed of 100 r/min, an error of 200 pulses (for HG series
servo motor) is generated in the home position. The higher the creep speed, the
greater the error of the home position.
After the front end of the proximity dog is detected, if a home position return is
terminated without reaching the creep speed, [AL. 90.2 Home position return
abnormal termination] occurs. Set the travel distance long enough for the travel
distance after proximity dog and the home position shift distance to decelerate
from the homing speed to the creep speed.

Deceleration starts from the front end of the proximity dog. The position is shifted by the travel distance after
proximity dog and the home position shift distance. The position after the shifts is set as the home position.
Homing can be performed independently of the Z-phase signal. Changing the creep speed may change 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: -7
Address decreasing direction: -39

Dog input polarity

[Pr. PT29 Function selection T-3]

Refer to section 12.4.1 (2) (b) to select the 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 this when shifting the home position from where
the front end of a proximity dog is passed.

Travel distance after proximity
dog

[Pr. PT09 Travel distance after proximity dog],
[Pr. PT59 Travel distance after proximity dog
(extension parameter)]

Set the travel distance 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.