16 - 68
16. INDEXER POSITIONING OPERATION
(3) Structure
Component Description
Servo amplifier
Servo motor Use standard models.
Battery MR-J3BAT
Encoder cable Use a standard model. (Refer to section 14.1.)
(4) Outline of absolute position detection data communic ation
For normal operation, as shown below, the encoder cons ists of a detector designed to detect a position
within one revolution and a cumulative revo lution counter designed to detect the number of revolutions.
The absolute position detection system alwa ys 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 th e time of machine installation, home position retur n is not
needed when power is switched on thereafter.
If a power failure or a fault occurs, restoration is easy.
MR-J3BAT
LSO
1XO
I/O circuit
Position data, speed data
(current position read)
Home position return
data
EEP-ROM memory
Backup at
power off
LS
Speed detection
1X
Detection of position
within one revolution
Within one-revolution counter
High-speed serial
communication
Speed control
Position control
1 pulse/rev. Cumulative revolution counter
Point table No. selection,
etc.
Servo amplifier
Servo motor
Current position
(5) Battery installation procedure
WARNING
Before installing a battery, turn off the main circu it power while keeping the control
circuit power on. Wait for 15 minutes or more until the char ge lamp turns off. Then,
confirm that the voltage between P( ) and N( ) is safe with a voltage tester and
others. Otherwise, an electric shock may occur. In addition, alwa ys confirm from
the front of the servo amplifier whether the char ge lamp is off or not.
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 conn ector pins and electrical
parts, directly by hand.
Before starting battery changing procedure, make sure that the main circuit
power is switched OFF with the control circuit power ON. When batter y is
changed with the control power OFF, the absolute position data is lost.