Absolute Position Detection System - Mitsubishi Electric MELSERVO-J2-Super Series Instruction Manual

5. OPERATION

5.5 Absolute position detection system

This servo amplifier contains a single-axis controller. Also, all servo motor encoders are compatible with
an absolute position system. Hence, an absolute position detection system can be configured up by merely
loading an absolute position data back-up battery and setting parameter values.
(1) Restrictions
An absolute position detection system cannot be built under the following conditions:
1) Stroke-less coordinate system, e.g. rotary shaft, infinite positioning.
2) Operation performed in incremental value command type positioning system.
(2) Specifications
System
Battery
Maximum revolution range
(Note 1) Maximum speed at power failure
(Note 2) Battery backup time
(Note 3) Data holding time during battery
replacement
Battery storage period
Note: 1. Maximum speed available when the shaft is rotated by external force at the time of power failure or the like.
2. Time to hold data by a battery with power off. It is recommended to replace the battery in three years
independently of whether power is kept on or off.
3. Period during which data can be held by the super capacitor in the encoder after power-off, with the battery
voltage low or the battery removed, or during which data can be held with the encoder cable disconnected.
Battery replacement should be finished within this period.
(3) Structure
Servo amplifier
Servo motor
Battery
Encoder cable
Item
Component
Electronic battery backup system
1 piece of lithium battery ( primary battery, nominal
Type: MR-BAT or A6BAT
Home position 32767 rev.
500r/min
Approx. 10,000 hours (battery life with power off)
2 hours at delivery, 1 hour in 5 years after delivery
5 years from date of manufacture
Use standard models.
MR-BAT or A6BAT
Use a standard model.
When fabricating, refer to Section 15.1.4.
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Description
Description
3.6V)