Delta ASD-A2-0121 Series User Manual page 652

Chapter 10 Troubleshooting
AL500：STO function is enabled
Causes
Safe torque off function
(STO) is enabled.
AL501： STO_A loss (signal loss or signal error)
Causes
Loss of STO_A signal or
STO_A and STO_B
signals are not
synchronized for more
than 1 sec.
AL502：STO_B lost (signal loss or signal error)
Causes
Loss of STO_B signal or
STO_A and STO_B
signals are not
synchronized for more
than 1 sec.
AL503：STO_error
Causes
An error occurs during
STO self-diagnosis.
AL555：System failure
Causes
DSP processing error
Checking Method
Safe torque off function (STO) is
enabled. Please check why it is
enabled.
Checking Method
Check if the wiring of STO_A is
correct.
Checking Method
Make sure the wiring of STO_B is
correct.
Checking Method
N/A
Checking Method
N/A
Corrective Actions
Use DI.ARST or 0x6040.Fault
Reset, or set P0-01 to 0.
Corrective Actions
Use DI.ARST or 0x6040.Fault
Reset, or set P0-01 to 0.
Corrective Actions
Use DI.ARST or 0x6040.Fault
Reset, or set P0-01 to 0.
Corrective Actions
It might be that the STO circuit is
causing the error. Please contact
the distributor.
Corrective Actions
If AL555 occurs, do not do anything
and send the drive back to Delta.
ASDA-A2
10-37