Mitsubishi FX3UC Series User Manual

393
FX3UC Series Programmable Controllers
User’s Manual - Hardware Edition
12 Test Operation, Adjustment, Maintenance and Troubleshooting
12.5 Troubleshooting with LEDs
11
Memory Cassette/Battery
12
Test Run, Maintenance, Troubleshooting
A
Version Information
B
Performance Specifications
C
Special Devices (M8000 -,D8000 -)
D
Instruction List
E
Character-code
F
Discontinued models
12.5.3 ERR LED [on/flashing/off]
12.5.4 L RUN LED (Only FX3UC-32MT-LT)
State of
LED
State of PLC Remedies
On
A watchdog timer error may have
occurred, or the hardware of the PLC
may be damaged.
1) Stop the PLC, and re-apply power.
If ERR LED goes off, a watchdog timer error may have
occurred. Take any of the following measures.
- Review the program.
The maximum value (D8012) of the scan time should not
exceed the setting (D8000) of the watchdog timer.
- Check that the input used for input interruption or pulse
catch is not being abnormally turned on and off in one scan.
- Check that the frequency of the pulse (duty of 50%) input to
the high-speed counter does not exceed the specified
range.
- Add the WDT instructions.
Add some WDT instructions to the program, and reset the
watchdog timer several times in one scan.
- Change the setting of the watchdog timer.
Change the watchdog timer setting (D8000) in the program
so that the setting is larger than the maximum value of the
scan time (D8012).
2) Remove the PLC and supply power to it from another power
supply on a desk.
If the ERR LED goes off, noise may have affected the PLC.
Take the following measures.
- Check the ground wiring, and reexamine the wiring route
and installation location.
- Fit a noise filter onto the power supply line.
3) If the ERR LED does not go off even after the measures
stated in (1) and (2) are taken, consult your local Mitsubishi
Electric distributor.
Flashing
One of the following errors has
occurred in the PLC.
• Parameter error
•Syntax error
• Ladder error
Perform PLC diagnosis and program check with the
programming tool.
For the remedies, refer to Section 12.6 "Judgment by Error
Codes and Representation of Error Codes".
Off
No errors that stop the PLC have
occurred.
If the operations of the PLC are abnormal, perform PLC
diagnosis and program check with the programming tool.
An I/O error, Comms.error or Runtime error may have occurred.
Mode
State of
LED
State of PLC Countermeasures
ONLINE
On Data link is being executed -
Off Data link is stopped • Take action according to the L ERR LED status.
CONFIG
On Data link is being executed -
Off Data link is stopped • Take action according to the L ERR LED status.
TEST
On
Self-loop back Test was
finished normally
-
Off
Self-loop back Test was
finished abnormally
(Extinguished while the self-
loop back Test is being
executed)
• Make sure that the power is correctly supplied to the PLC.
• If the L RUN LED is on even after the above check, consult
a Mitsubishi Electric Distributor.

Mitsubishi FX3UC Series Specifications

General

Brand	Mitsubishi
Model	FX3UC Series
Category	Controller
Language	English