8.4 Zero Point Return (ZRET)
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8.4 Zero Point Return (ZRET)
When the Zero Point Return command (ZRET) is executed, the axis will return to the zero point of the machine
coordinate system. The operation to detect the position of the zero point is different between an absolute encoder
and an incremental encoder. With an absolute encoder, positioning is performed to the zero point of the machine
coordinate system and command execution is completed. With an incremental encoder, there are 13 different
methods that can be performed for the Zero Point Return operation.
(1) Selecting the Zero Point Return Method
With an incremental encoder, the coordinate system data will be lost when the power supply is turned OFF. This
command must be executed when the power supply is turned ON again to establish a new coordinate system.
The 13 methods that are provided for the zero point return are listed in the following table. Select the best method
for the machine in the setting parameters.
Setting
Parameter
OW
3C
Name
Method
Remarks
0
DEC1 + C-Phase
Applies a 3-step deceleration method using the
deceleration limit switch and phase-C pulse.
DEC1 signal:
The SERVOPACK DEC signal.
1
ZERO signal
Uses the ZERO signal.
ZERO signal:
The SERVOPACK EXT1 signal.
2
DEC 1 + ZERO signal
Applies a 3-step deceleration method using the
deceleration limit switch and ZERO signal.
DEC1 signal:
The SERVOPACK DEC signal.
ZERO signal:
The SERVOPACK EXT1 signal.
3
C-Phase
Uses the phase-C pulse.
11
C pulse Only
Uses only the phase-C pulse.
12
POT & C pulse
Uses the positive overtravel signal and phase-C
pulse.
POT:
The SERVOPACK POT signal.
13
POT Only
Uses only the positive overtravel signal.
POT:
The SERVOPACK POT signal.
This method must not be used if
repeat accuracy is required.
14
Home LS & C pulse
Uses the home signal and phase-C pulse.
HOME:
The SERVOPACK EXT1 signal.
15
Home Only
Uses only the home signal
.
HOME:
The SERVOPACK EXT1 signal.
16
NOT & C pulse
Uses the negative overtravel signal and phase-
C pulse.
NOT:
The SERVOPACK NOT signal.
17
NOT Only
Uses only the negative overtravel signal.
NOT:
The SERVOPACK NOT signal.
This method must not be used if
repeat accuracy is required.
18
INPUT & C pulse
Uses the INPUT signal and phase-C pulse.
INPUT:
Setting parameter OB
05B
19
INPUT Only
Uses only the INPUT signal.
With this method, a zero point return
can be performed without
connecting an external signal using
setting parameter OB
05B.
This method must not be used if
repeat accuracy is required.
