Error Indicators; Troubleshooting; Plc Errors - Omron CQM1-ARM21 Operation Manual

Error indicators

6-1 Error indicators

6-2 Troubleshooting

6-2-1 PLC Errors

Symptoms
I/O BUS ERR An I/O unit, or the end cover, is not connected
properly.
FALS C0
CPU RUN LED
An I/O unit is defective.
remains OFF
CPU ERR LED is
ON
I/O UNIT OVER The number of I/O words on the installed I/O
units exceeds the maximum for this CPU type.
FALS E1
CPU RUN LED
remains OFF
CPU ERR LED is
ON
54
The CQM1-ARM21 uses the following means of error indication:
•
LED indicators: RUN, ERR, APF, CER, Slave status LEDs.
See 2-1-2, LED Indicators.
•
Status Flags: Config_OK, Normal_Operation, System Error.
See 4-4-1, Status Flags.
In case of malfunctions, check the status of all LEDs and Status Flags, and
refer to the troubleshooting tables in this chapter to determine the cause.
Possible problems have been divided in the following categories:
•
PLC Errors
•
Start-up problems
•
Configuration problems
•
AS-Interface communication problems
Mounting the AS-Interface master unit in a CQM1 PLC system can cause the
following errors to be indicated by the CQM1 CPU unit.
If the CQM1 CPU fails to start up correctly after power-on, the RUN LED of
the CQM1-ARM21 will blink to indicate that its initialisation could not be
completed.
Possible cause Possible remedy
Turn the PLC's power OFF and check for
loose units. Lock all units together with the top
and bottom sliders an re-apply the power.
Turn the PLC's power OFF and one by one
remove the I/O units until the error
disappears. Replace the unit causing the
error.
Check the ARM21's switch settings to
determine the number of I/O words required
by the Unit, and compare with the maximum
allowed value for the used CPU.
Turn the PLC's power OFF, then either:
•
Reduce the ARM21's I/O allocation.
•
Remove I/O units from the CQM1 system.
•
Select a CPU type with larger I/O
capacity.
PLC Settings
See also 4-1,
types that support 31 AS-Interface slaves.
Section 6-1
, for PLC CPU