3.2  Operations
3-65
9
head1
3
Utility Function Mode
 When “Error” Flashes on the Display
 When An Error Occurs 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 occur-
ring or the positioning com-
pleted signal (/COIN) is 
turning ON and OFF when 
the servomotor is stopped.
• 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 adjust-
ment function and the vibration 
suppression function.
An error occurred 
during the calculation 
of the moment of 
inertia.
Refer to the following table  When An Error Occurs during Cal-
culation of Moment of Inertia.
Travel distance setting 
error
The travel distance is set to 
approximately 0.5 rotation 
(0.05 rotation for SGMCS 
servomotor) or less, which 
is less than the minimum 
adjustable travel distance.
Increase the travel distance. It is 
recommended to set the number of 
motor rotations 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 narrow or pro-
portional control (P control) 
is being used.
• Increase the set value for Pn522.
• Set V_PPI in the Option field to 
0.
The moment of inertia 
cannot be calculated 
when the tuning-less 
function was activated.
When the tuning-less func-
tion was activated, Jcalc was 
set to OFF so the moment of 
inertia was not calculated.
• Turn OFF the tuning-less func-
tion.
• Set Jcalc to ON, so the moment 
of inertia will be calculated.
Error 
Display
Probable Cause Corrective Actions
Err1
The SERVOPACK started calculating 
the moment of inertia, but the calcula-
tion was not completed.
• Increase the speed loop gain (Pn100).
• Increase the STROKE (travel dis-
tance).
Err2
The moment of inertia fluctuated greatly 
and did not converge within 10 tries.
Set the calculation value based on the 
machine specifications in Pn103 and 
execute the calculation with the Jcalc set 
to OFF.
Err3 Low-frequency vibration was detected.
Double the set value of the moment of 
inertia calculating start level (Pn324).