Mitsubishi Electric MELSEC iQ-R RD78G4 User Manual page 142

Position value after composite main shaft gear at synchronous control start
The position value after composite main shaft gear is restored as follows according to the main input axis operation executed
before starting synchronous control.
Operation of main
input axis
(Before synchronous
control start)
Home position return
Current value change
*1
Speed control
Fixed-pitch feed control
Speed-position switching
*1
control
Position-speed switching
*1
control
Connection to servo
amplifier
Connection to
synchronous encoder
Others
*1 When "[Pr.300] Servo input axis type" is either "1: Command position value" or "2: Actual position value", and when "[Pr.21] Command
position value during speed control" is "2: Clear command position value to zero" only.
*2 When the unit setting of the servo input axis is set to degree, the servo input axis value is rounded within the range of 0 to 359.99999°
and the difference from the position value of the servo input axis under the last synchronous control is restored as the amount of change
as described in the following restoration method 2).
*3 If the servo input axis is moved beyond ±2147483647 (input axis unit) from the last synchronous control before the synchronous control
is started, the correct amount of change cannot be calculated.
*4 If the synchronous encoder axis via CPU is moved beyond "Resolution of synchronous encoder via CPU" from the last synchronous
control before the synchronous control is started, the correct amount of change cannot be calculated.
Restoration method 1): The new position value after composite main shaft gear is calculated based on the current value of the
main input axis.
Position value after composite main shaft gear =
Main input direction of composite main shaft gear  Main input axis current value
Restoration method 2): The movement amount of the main input axis from the last synchronous control session is reflected to
the position value after composite main shaft gear.
Position value after composite main shaft gear =
Position value after composite main shaft gear at the last synchronous control session + Main input direction of composite
main shaft gear  Amount of change of main input axis current value from the last synchronous control session
The position value after composite main shaft gear at the last synchronous control session is restored when "0: Invalid" is set
in "[Pr.400] Main input axis No.", or when a servo input axis or a synchronous encoder axis as the main input axis is not
connected.
"The last synchronous control session" indicates status just before the last synchronous control session was
stopped as follows. These are listed with the last synchronization status.
• Just before "[Cd.380] Synchronous control start" turns from ON to OFF.
• Just before deceleration stop by a stop command or an error, etc.
• Just before the power supply of the Motion module turns OFF
5 ADVANCED SYNCHRONOUS CONTROL INITIAL POSITION
140
5.1 Synchronous Control Initial Position
Servo input axis
Absolute Absolute
position position
detection system detection system
valid invalid
Restoration method 1)
Restoration method 1)
Restoration method 1)
Restoration method 1)
Restoration method 1)
Restoration method 1)
Restoration method Restoration method
*2*3
2) 1)

Restoration method 2)
Command Synchronous encoder axis
generation axis
Synchronous
encoder via
servo
amplifier
(incremental
system)
 
Restoration method 1) Restoration method 1)
Restoration method 1)

 
Restoration method 1)

 
 
Restoration

method 1)
Restoration method 2) Restoration method 2)
Synchronous Synchronous
encoder via encoder via
servo CPU
amplifier
(absolute
position
system)
Restoration Restoration
*4
method 2) method 2)