If "Errors" is shown
 Errors during Calculation of Moment of Inertia
The following table shows the probable causes of errors that may occur during the calculation of the moment 
of inertia with the Jcalc set to ON, along with corrective actions for the errors.
Error Probable Cause Corrective Actions
The gain adjustment was 
not successfully 
completed.
Machine vibration is occurring or the posi-
tioning completed signal (/COIN) is turning 
ON and OFF.
• Increase the set value for Pn522. 
• Change the mode from 2 to 3.
• If machine vibration occurs, suppress the 
vibration with the anti-resonance control 
adjustment function and the vibration 
suppression function.
The moment of inertia 
cannot be calculated 
when the tuning-less 
function was activated.
Jcalc was set to OFF, so the moment of 
inertia was not calculated and the tuning-
less function was activated.
• Turn OFF the tuning-less function.
• Set Jcalc to ON, so the moment of inertia 
will be calculated.
An error occurred during 
the calculation of the 
moment of inertia.
Refer to the following table  Errors during Calculation of Moment of Inertia.
Travel distance setting 
error
The travel distance is set to approximately 
0.5 rotation (0.05 rotation for SGMCS ser-
vomotor) or less, which is less than the min-
imum adjustable travel distance.
Increase the travel distance. It is recom-
mended to set the number of motor rota-
tions to around 3.
The positioning 
completed signal (/COIN) 
did not turn ON within 
approximately 10 seconds 
after positioning 
adjustment was 
completed.
The positioning completed width is too nar-
row or the proportional control (P control) 
is being used.
Increase the set value for Pn522. If P con-
trol is used, turn OFF the /P-CON signal.
Error 
Display
Cause Corrective Action
Err1
The SERVOPACK started calculating the 
moment of inertia, but the calculation was not 
completed.
• Increase the speed loop gain (Pn100).
• Increase the STROKE (travel distance).
Err2
The moment of inertia fluctuated greatly and 
did not converge within 10 tries.
Set the calculation value based on the machine specifi-
cations in Pn103 and execute the calculation with the 
Jcalc set to OFF.
Err3 Low-frequency vibration was detected.
Double the calculation starting level of the moment of 
inertia (Pn324).
Err4 The torque limit was reached.
• Increase the torque limit value.
• Double the calculation starting level of the moment 
of inertia (Pn324).
Err5
While calculating the moment of inertia, the 
speed control was set to proportional control 
with P-CON input.
Operate the SERVOPACK with PI control while calcu-
lating the moment of inertia.