Diagnosis

In the device tree, double-click the desired option board.
Select the “Diagnosis” tab to view the diagnosis messages of the desired option board.

Severity	Error	Description	Remedy
Option board error (Channel 255)
3	3	Timeout Communication timeout to CPU	If the process voltage is connected properly, replace the option board.
3	51	Invalid slot Wrong or missing option board in the appropriate slot	Check the configuration and the hardware setup.
4	11	Process voltage is too low	Check the process voltage.
4	34	Data not ready Data synchronization warning	Check PLC program and synchronize. ¹)
3	40	SW-mismatch Hardware does not match the firmware version	Replace the option board.
3	53	Download failed Power loss during firmware update	Replace the option board. ²)
3	9	DIAG_BUF_OVERFLOW Overflow in Diagnosis buffer	Diagnosis overflow usually means too many repeated warnings or errors. Please check all diagnosis in detail and take the appropriate action. A restart will clear the diagnosis.
3	43	DIAG_INTERNAL_ERR Internal error in the option board	Replace the option board.
3	26	DIAG_CFG_PRM_ERR Parameterization error	Check the CPU parameterization.
3	19	DIAG_CRC_ERR Checksum error in option board	Replace the option board.
Channel warning
4	304	Overload or cut wire	Check the input value.
4	263	Measurement underflow at the module.	Check the output values and the wiring.
4	260	Measurement overflow at the module.	Check the output values and the wiring.

Remarks:

¹)	If no other error occurs, the programs are not identical and the parameter is set to report an error in this case.
²)	Do not remove the power supply of the CPU during the firmware update.