YASKAWA MP2000 Series User Manual page 173

7.2 Motion Command Details
7.2.3 Zero Point Return (ZRET)
[ g ] DEC2 + Phase-C Signal Method (OW3C = 6)
With this method, the machine's position is confirmed by the ON/OFF status of the DEC2 signal and the retracting
operation is performed automatically, so the zero point return is always performed with the same conditions.

Starting the Zero Point Return in the High Region
1.
Travel is started in the positive direction at the speed specified by the Speed Reference Setting (setting
parameter OL10).
2.
When the falling edge of the DEC2 signal is detected, the axis decelerates to a stop.
3.
After decelerating to a stop, the axis travels in the reverse direction at the Approach Speed (setting
parameter OL3E).
4.
When the rising edge of the DEC2 signal is detected, the axis decelerates to a stop.
5.
After decelerating to a stop, the axis travels in the forward direction at the Creep Rate (setting parame-
ter OL40).
6.
After the falling edge of the DEC2 signal is detected, the position is latched when the rising edge of the
first phase-C pulse is detected.
7.
The axis moves from the latched position by the distance set in the Zero Point Return Travel Distance
(setting parameter OL42) and stops. The machine coordinate system is established with this final
position as the zero point.
DEC2
(DI_5 or OW 05, bit 8)
 If an OT signal is detected during the zero point return operation, an OT alarm will occur.
7-34
High region
Speed Reference Setting
(OL
N-OT
(DI_4)
Start
Phase-C signal
10)
Phase-C signal
latch at this point
Zero Point Return Travel Distance
Approach Speed (OL
Low region
Creep Rate
(OL 40)
End
3E)
P-OT
(DI_3)