Yaskawa MP920 Motion Module - Manual (Page 86)

2 Motion Control
2.4.4 Zero Point Return (ZRET)
2-60
„ DEC1 + LMT + Phase-C 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 (Phase-C pulse) by rapid
traverse using linear acceleration/deceleration (with a dog width).
The limit switch (deceleration limit switch) and the zero point return limit signal are used
with a mechanical configuration such as the one shown in the following illustration.
* 1. Zero point return reverse limit signal (OB††21C)
* 2. Zero point return forward limit signal (OB††21D)
Zero Point Return Operation Started and Interval (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.
6. After the falling edge of the dog (deceleration limit switch) is detected, the axis stops
SVA-01A SVA-02A SVB-01 PO-01
Available Available Not available Not available
High
Low
High
Low
High
Low
a. b. c. d. e.
Deceleration
limit switch
Interval
LMT_L *1
LMT_R *2
Machine total
operating area
Reverse direction ← → Forward direction
0
1.
2.
5.
4. 3.
6.
Speed
reference Rapid traverse speed
Dog
(Deceleration limit switch)
Zero point signal
(Phase-C pulse)
Creep speed
Approach speed
Zero point
Zero point
return position
Time
Zero point return
final travel distance
Reverse direction ← → Forward direction