Absolute Position Restoration Function; Configuration And Preparation Of The Absolute Position Detection System - Mitsubishi Electric MELSEC iQ-R-RD75P4 User Manual

7.7

Absolute Position Restoration Function

CAUTION
An absolute position restoration by the positioning function may turn off Servo ON signal (servo off) for approximately 60ms
+ scan time, and the motor may run unexpectedly. If this causes a problem, provide an electromagnetic brake to lock the
motor during absolute position restoration.
Absolute position restoration function restores the absolute position of the specified axis using the absolute position detection
system. When this function is used, the OPR after power off due to an instantaneous power failure and emergency stop is not
required, and the restoration operation at site can be performed easily.
Configuration and preparation of the absolute position detection
system
Configuration
The following figure shows the configuration of the absolute position detection system.
Power
Servo
supply
amplifier
(3)
Encoder cable
Servomotor with absolute position detector
Preparation
Prepare the absolute position detection system with caution by referring to the following descriptions.
Component
(1) Servo amplifier
(2) Servomotor
(3) Encoder cable
(4) Programmable controller system
7 CONTROL SUB FUNCTIONS
264
7.7 Absolute Position Restoration Function
Absolute position holding battery
(1)
Control signal connector
(2)
Description
• Use a Mitsubishi General-Purpose AC Servo which has an absolute position detection function (absolute position
data transfer protocol) equivalent to that of MR-J3-A).
• Install the battery to the servo amplifier.
• Validate the absolute position detection function of the servo amplifier.
For details, refer to the manual for the servo amplifier used.
• Use a servomotor with absolute position detector.
For details, refer to the manual for the servo motor used.
• Add a battery power connection cable (BAT/LG signal) to the incremental encoder cable connection.
For details, refer to the manual for the cable used.
• Establish the communications of absolute position detection data using I/O modules (three input points /three
output points).
• Use I/O modules with any number of points.
• Allocating the three input signals in serial order facilitates the control with a program. This also applies to the three
output signals.
Programmable controller system
CPU module RD75 I/O module
Control
panel
(4)