6.9 Absolute Linear Encoders
6.9.1 Connecting an Absolute Linear Encoder
6-40
6.9
Absolute Linear Encoders
The absolute linear encoder records the current position of the stop position even when the power
supply is OFF.
With a system that uses an absolute linear encoder, the host controller can monitor the current
position. Therefore, it is not necessary to perform an origin return operation when the power supply to
the system is turned ON.
There are two types of linear encoders for Linear Servomotors. The usage of the linear encoder is
specified in Pn002 = n.
X
.
Refer to the following section for linear encoder models.
Feedback Resolution of Linear Encoder
•
Parameter Settings When Using an Incremental Linear Encoder
•
Parameter Settings When Using an Absolute Linear Encoder
6.9.1
Connecting an Absolute Linear Encoder
You can get the position data from the absolute linear encoder with EtherCAT communications. There-
fore, it is not necessary to wire the PAO, PBO, and PCO (Encoder Divided Pulse Output) signals.
If they need to be wired, refer to the following section.
Wiring the SERVOPACK to the Encoder
6.9.2
Structure of the Position Data of the Absolute Linear
Encoder
The position data of the absolute linear encoder is the distance (number of pulses) from the origin of
the absolute linear encoder.
The position data is signed 36-bit data.
When the SERVOPACK sends the position data, it sends the upper 16-bit data (with sign) separately
from the lower 20-bit data.
Parameter
Meaning
When Enabled Classification
Pn002
(2002
hex)
n.
0
(default setting)
Use the encoder as an incremental linear encoder.
After restart
Setup
n.
1
Use the encoder as an incremental linear encoder.
Parameter
Meaning
When Enabled Classification
Pn002
(2002
hex)
n.
0
(default setting)
Use the encoder as an absolute linear encoder.
After restart
Setup
n.
1
Use the encoder as an incremental linear encoder.
35
20 19
0
±
Upper 16 bits (with sign)
Lower 20 bits
