Omron C200HW-CORT21 Operation Manual page 53

Troubleshooting
Start-up problems
Description
No LEDs are ON or The PLC's power is off.
Blinking.
The Unit is defective.
The RUN LED is The same Unit number has been set on
Blinking. another Special I/O Unit, causing an I/O UNIT
OVER error in the PLC.
I/O table verification error. A Unit has been
removed or the Unit number setting has been
changed that caused an I/O SET ERR error in
the PLC.
Another Special I/O Unit or Interrupt Input Unit
has not been initialised, causing a CPU
WAIT'G error in the PLC.
The Unit is defective.
ERR LED is ON. A
The cause is reported in IR n+3.13, IR n+3.14
Message communication problems
Description
IOWR instruction The IOWR instruction contains syntax errors.
not successfully (EQ-flag is not set)
executed.
The control code is invalid or the specified
message length does not relate to the function
indicated by the control code. (EQ-flag is not
set).
The contents of the message is invalid.
The Unit is defective.
IORD instruction not The IORD instruction contains syntax errors.
successfully (EQ-flag is not set)
executed.
The control code is invalid or the specified
message length does not relate to the function
indicated by the control code (EQ-flag is not
set).
The Unit is defective.
User defined CAN The wrong identifier or data length was set in
message is not the IOWR message structure.
received by another
node.
The network cabling is not correct.
The Unit operates on a different baud rate than
the other node on the network.
Possible cause
fatal error was detected at
Possible cause
Turn the PLC's power supply on.
Replace the C200HW-CORT21.
Make sure that the same Unit number is not
used by more than one Special I/O Unit and
restart the PLC.
Verify the I/O table and/or register the I/O
table again.
Check and/or remove the defective Unit.
Replace the C200HW-CORT21.
start-up. Try to solve the cause and restart the Unit. If
this does not help, replace the Unit.
Check if the correct Machine number and
message length is specified in the IOWR
instruction.
Read the error log to find out the cause.
Check if the control code equals to #0003 or
#0004.
Check the message length.
Check the contents of the message.
Replace the C200HW-CORT21.
Check if the correct Machine number and
message length is specified in the IORD
instruction.
Read the error log to find out the cause.
Check if the control code equals to #0000.
Check the message length.
Replace the C200HW-CORT21.
Compare the identifier of the receiving node
with the one specified in the IOWR message
structure.
Check if the data length corresponds with the
amount of data bytes that the receiving node
expects to receive.
Check the error log. If the error log indicates
that the Unit was unable to transmit the
message, then check if the correct pins of the
bus connector are connected (see section 2-
1-5), if there are no short circuits, if the stub-
lines are not too long, and if the network is
terminated at the appropriate places (see
section 2-3).
Configure all the units on the network to the
same baud rate.
Section 5-2
Possible remedy
Possible remedy
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