Summary - Mitsubishi Electric MELSERVO-J4 series Instruction Manual

12. ABSOLUTE POSITION DETECTION SYSTEM
12. ABSOLUTE POSITION DETECTION SYSTEM
CAUTION

12.1 Summary

12.1.1 Features
For normal operation, the encoder consists of a detector designed to detect a position within one revolution
and a cumulative revolution counter designed to detect the number of revolutions.
The absolute position detection system always detects the absolute position of the machine and keeps it
battery-backed, independently of whether the servo system controller power is on or off. Therefore, once
home position return is made at the time of machine installation, home position return is not needed when
power is switched on thereafter.
Even at a power failure or a malfunction, the system can be easily restored.
If [AL. 25 Absolute position erased] or [AL. E3 Absolute position counter warning]
has occurred, always perform home position setting again. Otherwise, it may
cause an unexpected operation.
Refer to appendix 2 and 3 for battery transportation and the new EU Battery
Directive.
If [AL. 25], [AL. 92], or [AL. 9F] occur due to such as short circuit of the battery,
the MR-BAT6V1 battery can become hot. Use the MR-BAT6V1 battery with case
to prevent getting burnt.
POINT
For configuring the system absolute position detection system, there are two
batteries of MR-BAT6V1SET battery and MR-BAT6V1BJ battery for junction
battery cable. Compared with the MR-BAT6V1SET battery, The MR-BAT6V1BJ
battery for junction battery cable has the following advantages.
You can disconnected the encoder cable from the servo amplifier.
You can change the battery with the control circuit power supply off.
When absolute position data is erased from the encoder, always execute home
position setting before operation. The absolute position data of the encoder will
be erased in the followings. Additionally, when the battery is used out of
specification, the absolute position data can be erased.
When the MR-BAT6V1SET battery was used...
The encoder cable was disconnected.
The battery was replaced when the control circuit power supply was off.
When the MR-BAT6V1BJ battery for junction battery cable is used...
A connector or cable was disconnected between the servo motor and battery.
The battery was replaced with procedures other than those of (3) in section
12.2.2.
The MR-BAT6V1BJ battery for junction battery cable is only for the HG series
servo motors. It cannot be used with direct drive motors.
Do not use the MR-BAT6V1BJ battery for junction battery cable in the fully
closed loop system and scale measurement function.
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