Absolute Position Data Backup - Mitsubishi Electric MELSEC iQ-R Series User Manual

Absolute position data backup

When the absolute position system is used, the absolute position data of each axis is backed up. The absolute position data is
backed up linked to the axis variable and the axis type. At the current position restoration, if the setting values do not match
with the axis variable and the axis type of the absolute position data, the absolute position data will be discarded. (The
warning "Absolute Position Data Incorrect Warning" (warning code: 0D00H) occurs.)
Backup is executed while the homing request is FALSE. (When the homing request becomes TRUE, the absolute position
data is discarded.)
• Storage folder and file name
Storage folder: /Ich
File name: abs_axis.bin
• Memory capacity
Memory capacity of the absolute position data differs depending on the axis type. Specify memory capacity of the absolute
position data according to the axis type and the number of axes.
Memory capacity per one axis for each axis type is shown below.
Axis type
Real drive axis
Virtual drive axis
Virtual linked axis
Memory capacity used for the absolute position data can be specified in
System.PrConst.AddonAbsSystem.BackupRamSizeMax.
If the file size required for backup exceeds specified memory capacity when the current position value of each axis is restored,
the error "Insufficient Current Position Backup Capacity" (error code: 1ADFH) occurs and the target axis is not restored
completely. Reconsider the memory capacity and carry out software reboot.
Saving (backup) and restoration (restored) of the absolute position data
The absolute position data maintained inside the motion system can be data saved/restored by saving/restoring functions of
the engineering tool, etc. When exchanging the Motion module, restarting time can be shortened by saving/restoring not only
programs and parameters but also the absolute position data.
During backup or restoration, the motion system stops backing up the absolute position data. Do not turn OFF the power of
the motion system during backup or restoration.
After restring is completed, software reboot is required to enable the restored absolute position data. (The backup is at a
standstill and it can not be cleared until software reboot is carried out.)
For real drive axis, the homing request becomes TRUE when the restored absolute position data is different from HomeOffset
(home position), the device, and the resolution of the connected driver.
Ex.
When saving absolute position data to an SD card
1.
Set "ABCDH: backup stop request" in System.Cd.BackupRestore.
2.
Confirm System.Md.BackupRestoreStatus changes to "1: backup stop executed" and "2: backup stop".
3.
Transfer absolute position data "/lch/axis_abs.bin" to an arbitrary folder in an SD card by using file transfer (Execution
data backup).
4.
Set "0H: No request" to System.Cd.BackupRestore after confirming file transfer (Execution data backup).
5.
Confirm System.Md.BackupRestoreStatus changes to "3: backup stop cleared" and "0: backup restore not executed".
System.Cd.
BackupRestore
System.Md.
BackupRestoreStatus
Memory capacity [byte/axis]
220
90
90
0H ABCDH
0 1
0H
2 3 0
Backup stop
2 AXIS MANAGEMENT FUNCTIONS
2.6 Absolute Position Control
2
85