5.3 Setting the Zero Point before Starting Operation
5-8
5.3
Setting the Zero Point before Starting Operation
When Using an Incremental Encoder
When an incremental encoder is used in the slave station, carry out a zero point return opera-
tion after turning ON the power supply.
After the zero point is set, set the reference coordinate system to determine the work coordi-
nate zero point as required:
1.
Setting the Reference Coordinate System Using ZRET Command
Use the ZRET command to return the slave station to the zero point and set the reference coordinate
system based on the zero point.
2.
Setting the Reference Coordinate System Using POS_SET Command
Use the POS_SET command to set the reference coordinate system of the slave station.
•
Perform positioning to the reference position using a positioning command such as EX_POSING.
•
Send the POS_SET command with POS_SET_MODE.POS_SEL = APOS (= 0), POS_SET_-
MODE.REFE = 1, and POS_DATA = reference position.
ZPOINT and software limits are enabled after the reference coordinate system has been set.
When Using an Absolute Encoder
When an absolute encoder is used in the slave station, the SENS_ON command can be used
to set the reference coordinate system of the slave station. The reference coordinate system
will be set according to the position detected by the absolute encoder and the coordinate sys-
tem offset of the encoder (i.e., the offset between the encoder’s coordinate system and the ref-
erence coordinate system (device built-in parameter)).
The relationship between the reference coordinate system (CPOS and APOS), the encoder’s
coordinate system, and the coordinate system offset of the encoder are shown in the following
figure.
CPOS: Reference position
APOS: Feedback position
Common parameter 2
3
(Pn808): Ab
s
olute encoder origin off
s
et
Common Parameter 2
3
(Pn808)
Reference
coordinate
s
y
s
tem
(CPO
S
, APO
S
)
Current
po
s
ition
X
Reference
coordinate
s
y
s
tem zero point
Ab
s
olute encoder zero point
Encoder
coordinate
s
y
s
tem
X=
+ Common Parameter 2
3
(Pn808)
