Panasonic FP-M Hardware Manual page 125

When an ALARM LED is ON
<Condition: a system watchdog timer error occurs>
Set the mode selector of the FP-M
control board from RUN to PROG. and
turn the power OFF and then ON.
Set the mode selector of the FP-M
control board from PROG. to RUN.
When all LEDs are OFF
Check the power supply wiring.
Check if the power supplied to the
programmable controller is in the range
of the rating.
Make sure the direction is correct when
installing ROM memory on the FP-M
control board.
Disconnect the power supply wiring to
the other devices if the power supplied
to the FP-M control board is shared
with them.
• If the ALARM LED is turned ON again, there is probably an abnormality in the FP-M
control board. Please contact your dealer.
• If the ERR. LED is turned ON, go to page 115,
• If the ALARM LED is ON, the program execution time is too long. Check the
program, referring the following:
- Check if instructions such as
scan can never finish.
- Check that interrupt instructions are executed in succession.
• Be sure to check the fluctuation in the power supply.
• Installation in the wrong direction may cause the power supply to short.
• If the LEDs on the FP-M control board turn ON at this moment, the capacity of the
power supply is not enough to control other devices as well.
• Prepare another power supply for other devices or increase the capacity of the power
supply.
When an ERR. LED is ON.
JP LOOP
or are programmed in such a way that a
6-2. Troubleshooting
117