Absolute Encoder's Origin (Zero Point) Position Offset Setting - Omron CJ1W-NC271 - 12-2009 Operation Manual

Absolute Encoder Origin
8-6-5

Absolute Encoder's Origin (Zero Point) Position Offset Setting

When Absolute Origin Offset for G Series (Pn200) or Absolute Encoder Zero Point Position Offset for
G5 Series/W Series (Pn808) = 0 (Default)
1,2,3...
When Absolute Origin Offset for G Series (Pn200) or Absolute Encoder Zero Point Position Offset for
G5 Series/W Series (Pn808) = Not 0
Note
Setting the Absolute Encoder Zero Point Position Offset Using an Origin Search Operation
332
1. Start MECHATROLINK communications (establish a connection using
CONNECT).
2. Use jogging or other operation to place the machine in the mechanical or-
igin position. ORIGIN SEARCH cannot be used when using an absolute
encoder.
3. Confirm the feedback present position in the Servo unlocked state and set
the origin position offset based on this present position. When the Servo is
locked, the present position may oscillate, or deviation will accumulate in
the Servo Drive, which may prevent the correct set value from being ob-
tained for the origin position offset, causing displacement of the origin.
4. Reverse the sign of the value for the feedback present position read in step
3 and write this value in Absolute Encoder Zero Point Position Offset
(Pn808). Use SAVE SERVO PARAMETER to write the value to the Servo
Drive's non-volatile memory.
5. Execute DEVICE SETUP or turn the power to the Servo Drive OFF and
then ON again.
The absolute encoder origin position offset that has been set is now enabled.
When the Absolute Origin Offset for G Series (Pn200) or Absolute Encoder
Zero Point Position Offset for G5 Series/W Series (Pn808) is set to a value
other than 0, such as when replacing the Servomotor, use either of the follow-
ing methods to set the origin position offset.
Method 1: First set the origin position offset to 0 (set Absolute Origin Offset for
G Series (Pn200) or Absolute Encoder Zero Point Position Offset
for G5 Series/W Series (Pn808) to 0) using SAVE SERVO PARAM-
ETER), and then set it according to the setting method for when
Pn808 is 0.
Method 2: Use the above setting method for when the absolute encoder zero
point position offset is 0, and calculate the set value in step 4 using
the following equation.
New zero point position offset value = Present zero point position
offset value − Feedback present position
There is a limit to the number of times non-volatile memory in the Servo Drive
can be written (10,000 times). Do not save Absolute Origin Offset (Pn200) for
G Series or Absolute Encoder Zero Point Position Offset (Pn808) for G5
Series/W Series too frequently.
The Absolute Origin Offset for G Series (Pn200) and Absolute Encoder Zero
Point Position Offset for W Series (Pn808) can be automatically set at the end
of an origin search by executing the origin search with the following operation
pattern with a Position Control Unit with unit version 2.0 or later.
Operation pattern: Reversal mode 1
Origin detection method: Origin proximity input signal reversal, No origin
proximity input signal reversal, or Do not use origin proximity input signal
Section 8-6