Omron C200HW-PRM21 Operation Manuals page 104

Troubleshooting
I/O data communication problems (continued)
Description
Outputs are being Run bit (IR n.00) is OFF. This can be due to a
reset. fatal PLC error or due to a mode change to /
from PROGRAM mode.
IR n+2.02 set? If so, the 'Data_Control_Timer'
of one of the slaves has expired and the
'Auto_clear' is enabled. The master has
entered the network state 'Clear'. (see for more
details section 1-4-4)
The master or the transmission line has failed,
the watchdog of the slave (if enabled) has
switched the outputs of the slave to the fail-
safe state.
The PLC cycle time is greater than the
configured watchdog time of the slave which
results in expiration of the watchdog in the
synchronous mode. This switches the outputs
to the fail-safe state.
The Master Unit is faulty.
Outputs do not Run bit (IR n.00) is OFF. This can be due to a
change anymore fatal PLC error or due to a mode change to /
from PROGRAM mode, with DM m+17 = 1
(hold mode).
Program execution has stopped due to a fatal
PLC error or PLC is in PROGRAM mode and
DM m+17 = 1
The slave operates in 'Sync'-mode.
The Master Unit is faulty
Inputs do not Run bit (IR n.00) is OFF. This can be due to a
change anymore fatal PLC error or due to a mode change to /
from PROGRAM mode.
The slave operates in 'Freeze'-mode.
The Master Unit is faulty
ERR LED is A fatal error is detected. The cause is reported
switched ON in IR n+2.06 ~ IR n+2.08
88
Possible cause Possible remedy
Check if the PLC is in PROGRAM mode, or if
a fatal PLC has occurred. Find the cause of
the fatal error, set IR n.00 ON and operate the
outputs.
Check IR n+3 to find out where / what the
possible problem is.
Fix or remove the slave that caused the
master to enter the 'Clear' state or disable the
'Auto_clear' mode (see section 4-3-7)
Check the transmission line and master Unit
or disable the slave's watchdog (not
recommended).
Increase watchdog time or decrease PLC
cycle time or choose asynchronous mode.
Replace the Master Unit.
Check if the PLC is in PROGRAM mode, or if
a fatal PLC has occurred. Find the cause of
the fatal error, set IR n.00 ON and operate the
outputs.
Check if the PLC is in PROGRAM mode or if
a FALS error was generated.
In this mode the data is only updated after
another transmission of the 'Sync'-command.
If this is not desired, this mode should be
turned OFF. See section 5-3-1 for more
details.
Replace the Master Unit.
Check if the PLC is in PROGRAM mode, or if
a fatal PLC has occurred. Find the cause of
the fatal error, set IR n.00 ON and check the
outputs.
In this mode the data is only updated after
another transmission of the 'Freeze'-
command. If this is not desired, this mode
should be turned OFF. See section 5-3-1 for
more details.
Replace the Master Unit.
Try to solve the cause and / or restart the
Unit. If this does not help, replace the Master
Unit
Section 7-2