Mitsubishi Electric MELSEC iQ-R Series User Manual page 90

The current position restoration of the absolute position system can be classified into the following three methods.
Current position
restoration method
32-bit restoration (Driver
current position
restoration)
64-bit restoration (Driver
ABS counter position
restoration)
*1 Actual restoration possible range is - ((multiple revolution counter maximum value) / 2  (encoder resolution)) to ((multiple revolution
counter maximum value) / 2  (encoder resolution) - 1).
Unit of the restoration possible range from the reference position in 64-bit restoration
• Driver-based or motor encoder-based
• For the motor encoder-based unit, the driver side additional electric gear (Gear Ratio) is required for the Motion module to
execute the current position restoration. The restoration possible range is (the driver-based unit range)  (Gear Ratio).
In the real drive axis, which method was used for the current position restoration of the absolute position
system, "32-bit restoration, 64-bit restoration (backup position), or 64-bit restoration (home position)" is
recorded in the event history.
The following shows objects required to construct the absolute position system of 64-bit restoration.
Setting item
AxisName.PrConst.SlaveObject(STR
UCT(SLAVE_OBJECT_REAL))
vSyncAbsCounter
(SyncAbsCounter)
vSyncCycleCounter
(SyncCycleCounter)
vHomeCycleCounter
(HomeCycleCounter)
vHomeAbsCounter
(HomeAbsCounter)
vInitialPos
(InitialPos)
vInitialCycleCounter
(InitialCycleCounter)
vInitialAbsCounter
(InitialAbsCounter)
vMaxAbsCounter
(MaxAbsCounter)
If any one of the above parameters is not specified, 32-bit restoration is executed.
Precautions
Even if the above parameters have been specified, an error "Driver Restoration Data Incorrect" (error code: 1AE0H) will occur
and the current position restoration will not be completed when the Max ABS counter object is not nth power of zero or two.
Execute reconnecting after correcting the parameter of the drive unit.
2 AXIS MANAGEMENT FUNCTIONS
88
2.6 Absolute Position Control
Basis position Description
Home position Correctly executes the current position restoration within the
signed 32-bit integral number range [driver-based] from the
reference position.
Restores based on the driver current position (Position actual
value) by using a part of the backup data of the motion system.
Backup position Correctly executes the current position restoration within up to the
signed 64-bit integral number range
reference position.
Restores based on the driver movement amount by using backup
data of the motion system.
Home position Correctly executes the current position restoration within up to the
signed 64-bit integral number range
reference position.
Restores based on the driver home position and the position at
restoration by using a part of the backup data of the motion
system.
Setting description
Specifies the object ID storing the current encoder multiple revolution counter.
Specifies the object ID storing the current encoder positon within one revolution.
Specifies the object ID storing the encoder positon within one revolution at homing.
Specifies the object ID storing the encoder multiple revolution counter at homing.
Specifies the object ID storing Position actual value at connection.
Specifies the object ID storing the encoder positon within one revolution at connection.
Specifies the object ID storing the encoder multiple revolution counter at connection.
Specifies the object ID storing the maximum value of the multiple revolution counter.
Remark

Some objects are required to execute
*1
[driver-based] from the 64-bit restoration. If the object are not
set, 32-bit current position restoration
will be executed.
Restoration is executed based on the
*1
[driver-based] from the home position when the connected
slave device has been changed.