Yaskawa MP940 - Manual (Page 467)

11.4 Position Control Using Motion Commands
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11
Zero Point Return Operation Started with the Dog (Deceleration Limit
Switch) Signal in the Low Area
1. The axis travels at approach speed in the reverse direction.
2. The axis decelerates at the rising edge of the dog (deceleration limit switch) signal.
3. The axis travels at creep speed in the forward direction.
4. After the falling edge of the dog (deceleration limit switch) is detected, the axis stops
after traveling only the zero point return final travel distance (OLC02A) from the initial
zero point signal, and that position will be the machine coordinate system zero point.
„ 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 (OBC021C)
∗ 2. Zero point return forward limit signal (OBC021D)
0
3.
2. 1.
4.
Zero point
Speed
reference
Creep speed
Zero point return
position
Time
Approach speed
Zero point return final travel
distance
Zero point signal
(Phase-C pulse)
Reverse Forward ← →
Dog (Decelera-
tion limit switch)
LMT_L ∗1
LMT_R ∗2
High
LOW
High
Low
High
Low
a. b. c. d. e. Interval
Machine total operating area
Deceleration
limit switch
Reverse Forward ← →