5.9  Absolute Encoders
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5.9 Absolute Encoders
If using an absolute encoder, a system to detect the absolute position can be designed for use with the host 
controller. By using an absolute position detection system, an operation can be performed without a zero point 
return operation immediately after the control power supply is turned ON.
A battery case is required to save position data in the absolute encoder.
The battery is attached to the battery case of the encoder cable.
If an encoder cable with a battery case is not used, install a battery to the host controller.
Set Pn002.2 to 0 (factory setting) to use the absolute encoder.
The SEN signal and battery are not required when using the absolute encoder as an incremental encoder.
 PROHIBITED
• Do not install batteries in both the host controller and battery case. It is dangerous because that sets up a 
loop circuit between the batteries.
Parameter Meaning
When 
Enabled
Classification
Pn002
n.0
[Factory setting]
Uses the absolute encoder as an absolute encoder.
After restart Setup
n.1 Uses the absolute encoder as an incremental encoder.
The rotational serial data output range for a large-capacity Σ-V-series absolute position 
detecting system is different from the range for previous Σ-series systems. As a result, 
the infinite-length positioning system of the Σ servo drives must be changed for use with 
Σ-V large-capacity servo drives. Be sure to make the following system modifications.
∗ This is the resolution for a motor capacity of 22 kW or higher.
Series (Models)
Absolute 
Encoder 
Resolution*
Output Range 
of Rotational 
Serial Data
Action when Limit Is Exceeded
Σ Series 
(SGDB)
12-bit
15-bit
-99999 to 
+ 99999
• When the upper limit (+99999) is exceeded 
in the forward direction, the rotational 
serial data will be 0.
• When the lower limit (-99999) is exceeded 
in the reverse direction, the rotational serial 
data will be 0.
Σ-II Series 
(SGDM/SGDH) 
or large-capacity 
Σ-V Series 
(SGDV)
17-bit
20-bit
-32768 to 
+ 32767
• When the upper limit (+32767) is exceeded 
in the forward direction, the rotational 
serial data will be -32768.
• When the lower limit (-32768) is exceeded 
in the reverse direction, the rotational serial 
data will be +32767.
Note: If you change the multiturn limit set-
ting (Pn205), the operation will be different 
for both forward and reverse rotation. (Refer 
to 5.9.6 Multiturn Limit Setting.)