Mitsubishi Electric Q172CPU Programming Manual page 162

5 POSITIONING DEDICATED SIGNALS
When using the absolute position system function, on starting up, and when the Motion
controller or absolute value motor has been replaced, always perform a home position return.
In the case of the absolute position system, use the PLC program to check the home position
return request before performing the positioning operation.
Failure to observe this could lead to an accident such as a collision.
(b) This signal turns off when the servo error reset command (M3208+20n)
turns on or the servo power supply turns on again.
Servo error detection
Servo error detection signal
(M2408+20n)
Servo error reset command
(M3208+20n)
REMARK
(Note-1): Refer to APPENDIX 2.4 for the error codes on errors detected at the servo
amplifier side.
(8) Home position return request signal (M2409+20n)
This signal turns on when it is necessary to confirm the home position address
at the power supply on or during positioning control.
(a) When not using an absolute position system
1) This signal turns on in the following cases:
• Motion CPU power supply on or reset
• During a home position return
2) This signal turns off by the completion of home position return.
(b) When using an absolute position system
1) This signal turns on in the following cases:
• During a home position return
• Backup data (reference value) sum check error occurrence (power
supply on).
2) This signal turns off by the completion of home position return.
Operation in G28 of the Motion program changes by the ON/OFF of the
home position return request signal.
When home position return request
signal is OFF
When home position return request
signal is ON
ON
OFF
OFF
The axis starts from the current position, passes through the
specified mid point, and returns to the home position at high-
speed feed rate.
Proximity dog, count, data set, dog cradle, stopper or limit
switch combined type home position return is executed in
accordance with the home position returun data.
CAUTION
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ON