IS620P User Manual                                                                                            Chapter 6 Troubleshooting
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6.1.2 Speed 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 remains.
 
•
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 whether 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 0. 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".