Yaskawa MP920 User's Manual Design - Manual (Page 174)

4 Motion Control
4.4.4 Zero Point Return (ZRET)
4-60
„ DEC1 + LMT + C-phase Pulse
This method is used to perform zero point return using a limit switch (deceleration limit
switch), a zero point return limit signal, and a zero point signal (C-phase pulse) by rapid
traverse using linear acceleration/deceleration (with a dog width).
This method can be used in the mechaincal configuration with the limit switch (deceleration
limit switch) and the zero point return limit signal as shown in the illustration below.
* 1. Zero point return reverse limit signal (OB††21C)
* 2. Zero point return forward limit signal (OB††21D)
Zero Point Return Operation Started and Zone (a) Used
1. The axis travels at rapid traverse speed in the forward direction.
2. The axis decelerates at the falling edge of the dog (deceleration limit switch) signal.
3. The axis travels at approach speed in the reverse direction.
4. The axis decelerates at the rising edge of the dog (deceleration limit switch) signal.
5. The axis travels at creep speed in the forward direction.
SVA-01A SVA-02A SVB-01 PO-01
Applicable Applicable N/A N/A
Zone
LMT_L ∗1
LMT_R ∗2
High
Low
High
Low
High
Low
a. b. c. d. e.
Deceleration
limit switch
Machine total
operating area
Reverse direction ← → Forward direction
0
1.
2.
5.
4. 3.
6.
Reverse direction ← → Forward direction Zero point
Speed
reference
Rapid traverse speed
Approach speed
Creep speed
Zero point
return position
Dog
(Deceleration limit switch)
Zero point signal
(C-phase pulse)
Zero point return
final travel distance
Time