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10 USING A FULLY CLOSED LOOP SYSTEM
10.7 Absolute position detection system
10.7
Absolute position detection system
Structure
An absolute position linear encoder is required to configure an absolute position detection system under fully closed loop
control using a linear encoder.
In this case, an encoder battery need not be installed to the drive unit.
When a battery backup type rotary encoder is used, an absolute position detection system can be configured by installing the
encoder battery to the drive unit.
When a batteryless rotary encoder is used, the encoder battery need not be mounted to the drive unit.
• Use an absolute position type encoder for the load-side encoder.
Using an incremental type encoder triggers [AL. 037 Parameter error].
• Switching between semi closed loop control and fully closed loop control cannot be performed. Set [Pr.
PE01.0 Fully closed loop function selection] to "0" (Always enabled).
If [Pr. PE01.0 Fully closed loop function selection] is set to "1" (switching by fully closed loop selection
command from the controller and by input device CLD), [AL. 037 Parameter error] occurs.
• Use the encoder within the range of 32-bit absolute position data. When using the degree unit, the infinite
feed function is enabled. For details, refer to "Infinite feed function" in the following manual.
MR-J5 User's Manual (Function)
• When a linear encoder is used for the load-side encoder, absolute position-related alarms ([AL. 025
Absolute position erased]) and warnings ([AL. 092 Battery cable disconnection warning] and [AL. 09F
Battery warning]) are not detected.
Precautions
When the absolute position detection system is configured with a rotary encoder, the battery life will be shorten because the
current consumption is increased as the power from the battery is supplied to both the servo motor-side and the load-side
encoder.
