12 CONTROL SUB FUNCTIONS
12.6 Absolute position restoration function
When the absolute position restoration is carried out, the servo ON signal may be turned OFF (servo OFF)
for about 20 ms, and the motor may operate. If this is not desired, install an electromagnetic brake
separately and lock the motor by that brake during the absolute position restoration.
Power
supply
Detector cable
Servomotor with absolute position detector
The "absolute position restoration function" is a function to restore the absolute
position of the designated axis by the absolute position detection system. By this
function, the OPR after power OFF such as instantaneous power interruption and
emergency stop is not required, and the restoration operation at site can be carried out
easily.
The details of the "absolute position restoration function" are described below.
[1] Configuration and preparation of absolute position detection system
[2] Outline of absolute position detection data 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 configuration of the absolute position
detection system.
Absolute position holding battery
1)
Servo
amplifier
3)
Control signal connector
2)
Fig. 12.32 Configuration of absolute position detection system
CAUTION
!
12 - 50
MELSEC-Q
4)
PLC system
QCPU
I/O
QD75
module
Operation
panel