Chapter 12 Absolute Position Detection System - Mitsubishi Electric MELSERVO-J4 Series Instruction Manual

12
ABSOLUTE POSITION DETECTION SYSTEM
CAUTION
• If [AL. 25 Absolute position erased] or [AL. E3 Absolute position counter warning] occurs, be sure to make perform home position setting again. Otherwise, it
may cause an unexpected operation.
• If [AL. 25], [AL. 92], or [AL. 9F] occurs due to a failure, such as short circuit of the battery, the MR-BAT6V1 battery may be hot. Use the MR-BAT6V1 battery
with a case to prevent getting burnt.
Refer to the following for the replacement procedure of the battery.
Page 384 Battery
For configuring the absolute position detection system, there are three batteries of MR-BAT6V1SET-A, MR-
BAT6V1BJ and MR-BT6VCASE. Compared with other batteries, MR-BAT6V1BJ has the following
advantages.
• You can disconnect 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.
When the MR-BAT6V1SET-A and MR-BT6VCASE are used
• The encoder cable was disconnected.
• The battery was replaced when the control circuit power supply was off.
When the MR-BAT6V1BJ is used
• A connector or cable was disconnected between the servo motor and battery.
• The battery was replaced with other procedure than in the following section. Page 391 Battery
replacement procedure
• When the battery is used out of specification, the absolute position data can be erased.
12.1
Summary
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 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.
12 ABSOLUTE POSITION DETECTION SYSTEM
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12.1 Summary