Chapter 6 Troubleshooting                                                                                            IS620P User Manual                                                 
- 116 -
During 
Startup
Fault 
Phenomenon
Cause Conrming Method
Input the 
speed 
reference.
The servo 
motor does not 
rotate or the 
motor speed is 
abnormal.
The speed 
reference (H0B-
01) is 0.
 
•
The AI wiring is incorrect.
When the speed reference is input through AI, 
check whether the AI input channel is selected 
correctly and check whether the AI is wired 
correctly by referring to Chapter 3 Wiring of 
Servo System.
 
•
The speed reference selection is incorrect.
Check whether H06-02 (speed reference 
selection) is set correctly.
 
•
The speed reference is not input or abnormal.
When AI is selected to input the speed 
reference, check whether the AI related 
parameters in group H03 are set correctly rst. 
Then check whether the input voltage is correct 
by observing the voltage on oscilloscope or 
viewing the AI sampling voltage in H0B-21 or 
H0B-22.
When digital setting is used to set the speed 
reference, check whether H06-03 (keypad 
setting value of speed reference) is set 
correctly.
When multi-speed is used to set the speed 
reference, check whether the parameters in 
group H12 are set correctly.
When communication is used to set the speed 
reference, check whether H31-09 (speed 
reference set via communication) is set 
correctly.
When jog speed reference is used to set the 
speed reference, check whether H06-04 (jog 
speed setting value) is set correctly, whether 
the DI functions FunIN.18: JOGCMD+ (forward 
jog) and FunIN.19: JOGCMD- (reverse jog) 
have been allocated and whether the logic of 
corresponding DIs is effective.
Check whether H06-05 (acceleration ramp 
time constant of speed reference) and H06-
06 (deceleration ramp time constant of speed 
reference) are set correctly.
Check whether the DI function FunIN.12: 
ZCLAMP (zero clamp function) is misallocated 
and whether the logic of corresponding DI is 
effective.