When the ON/OFF status of an external output cannot be changed
Is the L PW LED on?
Does the corresponding I/O LED of the output
module or I/O combined module turn on when an
external output signal is turned on?
Is the setting of the refresh device correct?
Is Remote READY (RWr0.b11) on?
Is the fast logic function used correctly?
Is any bit of Output Y channel status (RWr5) on?
If an external input cannot be read or an external output cannot be controlled even after the above actions are
taken, the I/O module may be failed. Please consult your local Mitsubishi representative.
When parameter read or write or CC-Link IE Field Network diagnostics fails
Is the D LINK LED of the I/O module on?
Is the version of the module on the master
Is the version of the engineering tool supported?
Do the setting of the network parameter and that
of the CPU module match?
Is the voltage of the module power supply
(24VDC) within the specified range?
Take corrective action according to the following.
Page 128 When the L PW LED does not turn on
If the LED turns on, there is a problem on the output wiring.
Check the wiring confirming that the output wiring is not disconnected or short-circuited.
Refer to the following as well.
Page 137 Troubleshooting for output circuit
Check the refresh parameter and correct the setting of the refresh device so that it matches with the setting
in the program. For the setting of the refresh parameters, refer to the following.
User's manual for the master/local module used
To enable changing the ON/OFF status of the external output when the module power supply is on, the
initial processing must be executed by using Initial processing request flag (RWr0.b8) and Initial processing
completion flag (RWw0.b8). Execute the initial processing to check that Remote READY (RWr0.b11) is on.
For details, refer to the following.
Page 144 Initial processing request flag (RWr0.b8)
Page 152 Initial processing completion flag (RWw0.b8)
When the fast logic function is enabled, output Y is turned on or off not by the remote output signals (RY)
received from the master module but by the internal operation result of the module. Disable the fast logic
function or change the condition of output.
For details on the fast logic function, refer to the following.
Page 95 Fast Logic Function
Page 157 Fast logic setting
When any bit of Output Y channel status (RWr5) is on, a short circuit was detected in the output signal for
Check the wiring after checking that the output wiring is not disconnected or short-circuited.
Check the D LINK LED of the I/O module. If the D LINK LED does not turn on, refer to the following to
Page 129 When the D LINK LED turns off
Page 129 When the D LINK LED flashes
Refer to the following to check other LEDs.
Page 128 Checking the LEDs
Check the serial number (first five digits) of the module on the master station, and if the version is prior to
the correct one, replace the module with a module of the applicable version. For the applicable version,
refer to the following.
Page 62 Applicable master station
Please consult your local Mitsubishi representative.
Perform PLC verification on the network parameter to check those settings. When they are not matched,
match the setting of the network parameter to that of the CPU module and write the module parameter of
the slave station.
Set the voltage value within the range of performance specifications.
11.5 Troubleshooting for Each Phenomenon