Chapter 6 Troubleshooting                                                                                            IS620P User Manual                                                 
- 110 -
Chapter 6 Troubleshooting
6.1 During Startup
6.1.1 Position Control
During 
Startup
Fault 
Phenomenon
Cause Conrming Method
Connect the 
control power 
L1C/ L2C 
and main 
power RST.
The LED 
display is not 
on or does not 
display Rdy.
1. The control 
power voltage is 
abnormal.
 
•
After disconnecting CN1, CN2, CN3 and CN4, 
the fault persists.
 
•
Measure the AC voltage between L1C and L2C.
2. The program 
burning terminal 
is shorted.
 
•
Check whether the program burning terminal is 
shorted.
3. The servo 
drive is faulty.
-
The operation 
panel displays 
"Er.xxx".
Refer to section 6.2 to eliminate the fault.
 ■ After the preceding causes are removed, the operation panel should display "Rdy".
Set the servo 
enabled 
signal (S-ON) 
to ON.
The operation 
panel displays 
"Er.xxx".
Refer to section 6.2 to eliminate the fault.
The shaft 
of the servo 
motor is in the 
free running 
state.
1. The servo 
enabled signal is 
ineffective.
 
•
Switch over the operation panel to the display of 
servo state and view whether the operation panel 
displays "Rdy" rather than "Run".
 
•
Check whether any parameter in groups H03 and 
H17 is allocated with the DI function 1 FunIN1: 
S-ON: (servo enabled). If yes, check that the 
corresponding DI is set to ON. If not, allocate the 
function and set the corresponding DI to ON.
 
•
If a parameter in group H03 has been allocated 
with the FunIN1: S-ON function and the 
corresponding DI is ON, but the operation panel 
still displays "Rdy". In this case, check whether 
the DI terminal is connected correctly by referring 
chapter 3 Wiring of Servo System.
2. Control 
mode selection 
incorrect
 
•
Check whether H02-00 is 1. If it is set to 2 
(torque mode), the motor shaft must be in the 
free running state because the default torque 
reference is 0.
 ■ After the preceding causes are removed, the operation panel should display "Run".