Yaskawa MP940 - Manual (Page 471)

11.4 Position Control Using Motion Commands
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„ ZERO Signal Method
Zero point return is performed using a ZERO signal (DI signal) in place of the Phase-C
pulse used in the Phase-C Pulse described above.
For details, see Phase-C Pulse.
The EXT2 signal of the SERVOPACK is used for the ZERO signal (DI signal).
„ Example of the Zero Point Return Operations
Use the following procedure to perform zero point return operations.
The following illustration shows an example of the DEC1 + Phase-C pulse method.
1. Set the initial values for the motion fixed parameters and the motion setting parameters
according to the user's machine.
2. Set the Position Control Mode (PCON) (bit 2 of OWC000).
3. Set the motion setting parameter to be used with zero point return (ZRET).
4. Set Servo ON (RUN) to ON (bit 0 of OWC001).
5. Set zero point return (ZRET = 3) in the motion command code (OWC020).
6. Start operation using the zero point return (ZRET).
0
1. 2. 3. 4.
RUN
ZRET
ZRNC
1 Set the motion fixed parameters.
Set the motion setting parameter
initial values.
2 Set the position control mode
(PCON).
3 Set the motion setting parameters.
4 Set Servo ON (RUN) to ON.
5 Execute the zero point return
(ZRET) motion command.
6 The axis travels at rapid traverse
speed in the specified direction.
7 The axis decelerates to approach
speed at the trailing edge of the
deceleration limit switch signal.
8 The axis decelerates to creep
speed at the rising edge of the
deceleration limit switch signal.
9 When the deceleration limit switch signal
goes high, the axis stops after traveling only
the zero point return final travel distance from
the initial zero point signal, and that position
will be the machine coordinate system zero
point.
10 The zero point return completed
status (ZRNC) turns ON.
11 Execute the motion command
(NOP (= 0)).
Direction specified as the zero
point return direction (OBC0009)
Reverse Forward
← → Zero point
Zero point return final
travel distance
Speed ref-
erence
Rapid traverse
speed
Approach
speed
Creep speed
Zero point
return posi-
tion
Time
Limit switch width 2
× Ts (Ts: High-speed
scan setting value)*2
≥
Zero point return
final travel distance
Dog (Decelera-
tion limit switch)
Zero point signal
(Phase-C pulse)
Positioning completed range
Area A Area B*1
: System execution
: User setting