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MELSEC-Q
 
5   DATA USED FOR POSITIONING CONTROL 
 
5.2.8 Servo adjustment parameters 
 
 
 
Item Setting details 
Setting value
1  
0 to 100.0[times]   
Pr.112
 
Load inertia ratio 
Used to set the ratio of the load inertia to the inertia 
moment of the servomotor. 
When auto tuning is selected, the result of auto tuning 
is automatically used. 
POINT
 
 
Pr.112
 
Load inertia ratio to 
Pr.117
 Speed integral 
compensation
 
 is transferred to servo amplifier in PLC 
CPU power on, reset and PLC READY signal (Y0) 
on. When auto tuning is executed, it is changed to the 
optimum value inside servo amplifier. 
The result of auto tuning is transferred to QD75 at this 
time. 
When auto tuning is invalid and wants to keep gain 
adjustment result by "GX Configurator-QP", a reading 
stock is executed by 
Cd.102
 
Servo amplifier read to 
QD75. 
After that, execute 
 Cd.1 
 
Flash ROM write request, 
and keep it in the flash ROM. 
0 to 300.0[times]   
4 to 1000[rad/s]   
Pr.113
 
Position loop gain 1 
Used to set the gain of position loop 1. Increase the 
gain to improve trackability performance in response 
to the position command. 
4 to 2000[rad/s]   
20 to 5000[rad/s]   
Pr.114
 
Speed loop gain 1 
Normally this parameter setting need not be 
changed. Higher setting increases the response 
level but is liable to generate vibration and/or noise. 
20 to 8000[rad/s]   
1 to 500[rad/s]   
Pr.115
 
Position loop gain 2 
Used to set the gain of the position loop. 
Set this parameter to increase position response to 
load disturbance. 
Higher setting increases the response level but is 
liable to generate vibration and/or noise. 
1 to 1000[rad/s]   
20 to 8000[rad/s]   
Pr.116
 
Speed loop gain 2 
Set this parameter when vibration occurs on 
machines of lowrigidity or large backlash. 
Higher setting increases the response level but is 
liable to generate vibration and/or noise. 
20 to 20000[rad/s]   
Servo adjustment parameters 
Pr.117
 
Speed integral compensation  Used to set the constant of integral compensation. 1 to 1000[ms]