9. TROUBLESHOOTING
MELSEC-A
9-1
9. TROUBLESHOOTING
This chapter explains the troubleshooting for the use of the A1SJ71PB92D.
LED
Definition
Measures
On
Normal
RUN
Off
Abnormal
The watchdog timer timed out.
Contact the nearest service center or
dealer.
Normal in mode 0 or E
On
Abnormal in other than
mode 0 or E
Offline or did not enter the self-diagnosis mode.
Contact the nearest service center or
dealer.
Normal in other than
mode 0 or E
READY
Off
Abnormal in mode 0 or E Did not enter the online mode.
Contact the nearest service center or
dealer.
On
Abnormal
There is a slave station with which initialization
exchange cannot be done. (The parameter and
actual slave station do not match.)
Check the parameter.
Flash
Normal
SD/RD
Off
Abnormal in mode 0 or E No exchange
Check the exchange start request
signal Y00.
On
Normal
Flash
Normal
Multi-master configuration in mode 0 or E
Normal in other than
mode 0 or E
TOKEN
Off
Abnormal in mode 0 or E Token does not cycle.
•
Check the cable and terminal
resistor.
•
Check for duplicate addresses.
•
Check if the HSA exceeds the
network maximum station No.
On
Normal in mode 1
No parameter written in the module.
Write the parameter in the module.
Flash
Abnormal
The E
2
PROM parameters are corrupted.
Initialize the E
2
PROM with the
E
2
PROM initialization function.
(Refer to Section 4.6)
PRM SET
Off
Normal
RSP ERR.
FAULT
The error definition varies with the combination of the RSP ERR. LED and FAULT LED states. Refer to the following table for
details.