Absolute Position System - Mitsubishi Electric MELSEC iQ-R16MTCPU Programming Manual

4.5

Absolute Position System

Absolute position system
The positioning control for absolute position system can be performed using the absolute-position-compatible servomotors
and servo amplifiers. If the machine position is set at the system starting, home position return is not necessary because the
absolute position is detected at the power on. Absolute data (current value backup data, home position data) used with
absolute system control is stored in the Motion CPU internal backup memory. The absolute position system configuration is as
follows.
Motion CPU
• Position command
• Control command
• Servo parameter
Current value
backup data
Home position
coordinates
Back and restoration of current value
Absolute position system start
Set the "Absolute position detection system (PA03)" in the servo parameters to "1" for axes used with the absolute position
system. To establish the machine position, perform home position return with the servo program servo command (ZERO), or
with test mode. (Page 328 Test Mode)
Establishing the absolute position
In the absolute positioning system, the absolute position may be lost in the following cases: Set the absolute position with a
home position return.
• The battery unit of the servo amplifier is removed or replaced.
• The battery error of the servo amplifier occurs. (It is detected at the servo amplifier power on).
• The machine system is disturbed by a shock.
• The cable between servo amplifier and encoder is removed, or the servo amplifier or encoder is replaced.
• If there is an abnormality with the counter of the absolute position encoder.
Monitoring the absolute position data
Absolute position data can be monitored with the MT Developer2 current value history monitor. (Page 333 Current value
history monitor)
4 AUXILIARY AND APPLIED FUNCTIONS
110
4.5 Absolute Position System
Battery
Servo amplifier
Monitor data
Servo motor
M
Backup
PLG
Absolute position encoder