Mitsubishi Electric Melservo-J3 Series MR-J3-B, Instruction Manual

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5. OPERATION
5.8 Absolute position detection system
CAUTION
If an absolute position erase alarm (A25) or an absolute position counter warning
(AE3) has occurred, always perform home position setting again. Not doing so
may cause unexpected operation.
POINT
If the encoder cable is disconnected, absolute position data will be lost in the
following servo motor series. HF-MP, HF-KP, HF-SP, HC-RP, HC-UP, HC-
LP, HA-LP and HF-JP. After disconnecting the encoder cable, always
execute home position setting and then positioning operation.
When the following parameters are changed, the home position is lost when
turning on the power after the change. Execute the home position return
again when turning on the power.
Parameter No.PA06 (Electronic gear numerator)
Parameter No.PA07 (Electronic gear denominator)
Parameter No.PA14 (Rotation direction selection)
Parameter No.PC07 (Home position return position data)
This servo amplifier has a built-in a single-axis controller, and all servo motor encoders are compatible with
absolute position detection system. Hence, mounting an absolute position data backup battery and setting
parameters enable absolute position detection system to be configured.
(1) Restrictions
An absolute position detection system cannot be configured 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
Item Description
System Electronic battery backup system.
Battery
1 piece of lithium battery ( primary battery, nominal 3.6V)
Type: MR-J3BAT
Maximum revolution range Home position 32767 rev.
(Note 1) Maximum speed at power failure 3000r/min
(Note 2) Battery backup time Approx. 10,000 hours (battery life with power off)
(Note 3) Battery life 5 years from date of manufacture
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. Replace the batteries within three years since the operation start
regardless of the power supply on/off. If the battery is used out of specification, the absolute position erased
(A25) may occur.
3. Quality of battery degrades by the storage condition. It is recommended that the battery be used within two
years from the date of manufacture. The life of battery is five years from the date of manufacture regardless of
the connection.