Run a unit test to check if there is any error in the I/O module.
Power off the module.
Connect the PORT1 and PORT2 connectors of the I/O
module with an Ethernet cable.
Set the station number setting switch as follows.
• x10: TEST
• x1: 0
For the setting procedure of the station number setting
switch, refer to the following.
Page 64 Setting procedure
Power on the module.
Unit test begins.
The MODE LED flashes while the unit test is being executed.
The MODE LED turns off when the unit test is
• If the test is completed normally, the ERR. LED does not
turn on, but remains off.
• If the test fails, the ERR. LED turns on. If the test fails,
replace the Ethernet cable and run the test again. If the
test fails again, it may be due to a hardware failure in the I/
O module. Please consult your local Mitsubishi
11.4 Unit Test