Mitsubishi melservo-j2 series Instruction Manual page 102

4. OPERATION
(4) Outline of absolute position detection data communication
For normal operation, as shown below, 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 general-purpose programming controller power is on
or off. Therefore, once the home position is defined at the time of machine installation, zeroing is not
needed when power is switched on thereafter.
If a power failure or a fault occurs, restoration is easy.
Also, the absolute position data, which is battery-backed by the super capacitor in the encoder, can be
retained within the specified period (cumulative revolution counter value retaining time) if the cable is
unplugged or broken.
Point table selection
signal, etc.
(5) Battery installation procedure
1) Open the operation window. (When the model used is the MR-J2-200C or more, also remove the
front cover.)
2) Install the battery in the battery holder.
3) Install the battery connector into CON1 until it clicks.
Operation window
Battery holder
Battery
For MR-J2-100C or less
Servo amplifier
I/O circuit
Position data, speed data
(current position read)
Servo motor
1 pulse/rev. Cumulative
revolution counter
Super capacitor
Within one-revolution counter
POINT
•The internal circuits of the servo amplifier may be damaged by static electricity.
Always take the following precautions:
•Ground human body and work bench.
•Do not touch the conductive areas, such as connector pins and electrical parts,
directly by hand.
Battery connector
CON1
Zeroing data
EEP-ROM memory
LSO
1XO
Backup at
power off
Speed detection
Battery MR-BAT
Battery connector
Battery
4 - 31
Current position
1X
LS
Detection of position
within one revolution
High-speed serial
communication
Battery holder
For MR-J2-200C or more
CON1