Mitsubishi Electric MELSEC iQ-R Series User Manual page 234

The method for compensating the error
When the position control is carried out using the "Electronic gear" set in a parameter, this may produce an error between the
command movement amount (L) and the actual movement amount (L'). With Motion module, this error is compensated by
adjusting the electronic gear.
The "Error compensation amount", which is used for error compensation, is defined as follows:
Error compensation
amount
The electronic gear including an error compensation amount is shown below.
AP
×
AL × AM
Motion module
Command
Control unit
value
Motion module
Command
Control unit
value
■Calculation example
(Conditions)
Number of pulses per rotation (AP) : 4194304 [pulse]
Movement amount per rotation (AL) : 5000.0 [μm]
Unit magnification (AM)
(Positioning results)
Command movement amount (L) : 100 [mm]
Actual movement amount (L')
[Compensation value]
AP
AL × AM
Number of pulses per rotation (AP') : 4194304 ... [Pr.2]
Movement amount per rotation (AL') : 5050.0 ... [Pr.3]
Unit magnification (AM')
Set the post-compensation "[Pr.2] Number of pulses per rotation (AP')", "[Pr.3] Movement amount per rotation (AL')", and
"[Pr.4] Unit magnification (AM')" in the parameters, and write them to the Motion module. The set details are validated at the
rising edge (OFF  ON) of the PLC READY signal [Y0].
8 CONTROL SUB FUNCTIONS
232
8.2 Functions for Compensating the Control
Downloaded from ManualsNet.com
Command movement amount (L)
=
Actual movement amount (L')
L AP'
=
L' AL' × AM'
AP
AL × AM
Electronic gear taking an error into consideration
AP'
AL' × AM'
: 1
: 101 [mm]
L
4194304
× =
L' 5000.0 × 1
: 1 ... [Pr.4]
search engine
L
Pulse Servo amplifier
L'
1 if there is no error (in regular case)
Pulse Servo amplifier
4194304 (AP')
100
× =
101 5050 (AL') × 1 (AM')