Omron CS1W-MC221 -, Operation Manual

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Input Signals Required for an Origin Search Section 9-2
Refer to 5-3 PLC Interface Area for details on these bits. For details on setting
up the absolute encoder from the Teaching Box, refer to the Teaching Box
Operation Manual (W320) .
9-2 Input Signals Required for an Origin Search
The following signal inputs and conditions are required to perform an origin
search.
CW and CCW Limit
Signals These signal inputs indicate that the workpiece’s maximum range, for clock-
wise (CW) or counterclockwise (CCW) motor rotation, has been reached.
Origin Proximity Signal This signal input indicates that the axis is near the origin.
Encoder’s Phase-Z Signal This signal is output when the encoder has made one revolution. Two phase-Z
signals are output per revolution in the case of OMRON M-series Servomo-
tors.
The first phase-Z position after the origin proximity signal input changes from
ON to OFF is the actual workpiece origin.
9-3 Origin Search Methods and Parameters
9-3-1 Origin Search Methods
There are three possible settings for the origin search method.
Set Origin at Power ON
Mode The origin is automatically set to the motor’s position when power is turned
ON.
If origin search is performed in this mode, the Unit will search for the position
of the motor at power ON.
Reverse Mode The direction is reversed if a limit signal input is received during the origin
search.
The origin will be established when the phase-Z signal goes ON after the ori-
gin proximity signal input goes from ON to OFF (normally open input).
When there is no origin proximity signal input, a limit signal input can be used
instead.
One-direction Mode The origin search is performed in just one direction. An error will occur if a
limit signal input is received before the origin proximity signal input.
Name Model Word Bit Description
X axis Y axis Z axis U axis
Absolute
Origin Set MC421
MC221 n+11
n+7 n+13
n+9 n+15
--- n+17
--- 06
↑
: Sets the absolute origin.
Origin
Search MC421
MC221 n+11
n+7 n+13
n+9 n+15
--- n+17
--- 01
↑
: Executes origin search.
Signal Description
CW and CCW limit signals Normally closed inputs are required.
Origin proximity signal The logic of this signal can be changed in the machine
parameters, so either normally closed or normally
open inputs can be used.
Encoder’s phase-Z signal The MC Unit detects the signal when it changes from
Low to High.