Batt Led [Lit Or Unlit]; Fx 3Uc ]; Error Led [Lit, Flickering Or Unlit] - Mitsubishi FX3U Series Programming Manual

FX /FX Series Programmable Controllers
3U 3UC
Programming Manual - Basic & Applied Instruction Edition
37.1.3 BATT LED [lit or unlit] [FX
LED status
Lit
Unlit
37.1.4 ERROR LED [lit, flickering or unlit] [FX
LED status
Lit
Flickering
Unlit
844
/FX
3U
PLC status
The battery voltage is low.
The battery voltage exceeds the value set in
D8006.
PLC status
A watchdog timer error has occurred, or
the hardware of the PLC may be
damaged.
Either of the following errors occur in PLC:
• Parameter error
• Syntax error
• Circuit error
Error which stops PLC is not occurred.
37.1 States and Colors of LEDs PLC Operation Status
]
3UC
Replace the battery as soon as possible.
(Refer to FX
The battery is normal.
/FX ]
3U 3UC
1) Change the PLC mode to STOP, and turn ON the PLC
power again.
When the ERROR LED is off, a watchdog timer error
occurred. Take either of the following actions:
- Review the program, and make sure that the
maximum value (D8012) of the scan time is not larger
than the set value (D8000) of the watchdog timer.
- Make sure that an input used for input interrupt or
pulse catch does not abnormally turn ON and OFF
several times in one scan time.
- Make sure that the frequency of the pulse (duty: 50%)
input to a high speed counter is within the
specifications range.
- Adding WDT instruction
Use two or more WDT instructions in a program so
that the watchdog timer is reset several times in one
scan time.
- Change the set value of the watchdog timer
Change the set value (D8000) of the watchdog timer in
a program so that it is larger than the maximum value
(D8012) of the scan time.
2) Remove the PLC, and connect another power supply to
the PLC.
If the ERROR LED is off, the cause of the error may be
noise. Examine the following action:
- Check the wiring for grounding, and then review the
wiring route and installation location.
- Add a noise filter in the power line.
3) If the ERROR LED is not off even after the step 1) or 2),
consult a Mitsubishi Electric Distributor.
Execute the PLC diagnostics and program check by
programming tool.
For the action, refer to Section 37.4.
If PLC operation is a failure, execute the PLC diagnostics or
program check by programming tool.
An I/O configuration error, serial communication error or
operation error may occur.
37 Error Check Method and Error Code List
Action
/FX Hardware edition.)
3U 3UC
Action