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MELSEC-Q
12 CONTROL SUB FUNCTIONS
12.6 Absolute position restoration function

! CAUTION

When the absolute position restoration is c arried out, the servo ON signal may be turn ed OFF (servo OFF)
for about 20 ms, and the motor may operate. If this is not desired, install an electromag netic brake
separately and lock the motor by that brake during the absolute posit ion restoration.
The "absolute position restoration function" is a function to restore the absolute
position of the designated axis by the absol ute position detection system. By this
function, the OPR after power OFF such as insta ntaneous power interruption and
emergency stop is not required, and the restor ation operation at site can be carried ou t
easily.
The details of the "absolute position restorat ion function" are described below.
[1] Configuration and preparation of absolute position detec tion system
[2] Outline of absolute position detection d ata communication
[3] Absolute position signal transmission procedure
[4] Precautions during control
[1] Configuration and preparation of absolute position detection system
(1) Configuration
The following drawing shows the configurati on of the absolute position
detection system.
Servo
amplifier
Power
supply
Detector cable
Absolute position holding battery
Control signal connector
1)
2)
3)
4)
PLC system
QCPU
QD75 I/O
module
Operation
panel
Servomotor with absolute position detector
Fig. 12.32 Configuration of absolute position detection sy stem