[Cause]
A signal was assigned to an I/O device that does not exist. No I/O device corresponds to the rack and slot values displayed after the alarm. Possible causes are:
(1) Replacement with other types of I/O devices.
(2) The I/O device fuse has blown.
(3) No power has been provided to the I/O device.
(4) I/O Link cable has been removed or not fully plugged in.
(5) The I/O Link cable is broken.
(6) I/O device failure.
[Countermeasure]
(1) When replacing I/O devices, erase I/O allocations according to the following steps.
1. Press MENU(menu) to select I/O, press F1([type]) to select the I/O connection device to display the I/O connection device image.
2. Press F5 (Clear).
3. The question "Clear all I/O assignments?" is displayed. Press F4 (Yes).
4. Turn the power off and back on. All output signals turn off at this time, even if power-failure processing is enabled.
(2) Replacement of fuses for I/O devices.
(3) Confirm the power source of the I/O device.
(4) Securely insert the I/O Link cable.
(5) Replacement of I/O Link cable.
(6) Replacement of I/O devices.