Cause : Hardware I/O resource loss comes when the selected DI hardware resource does not exist. Ensure that the power supply unit and extension cards are firmly installed. Check parameters F4-00 to F4-15 of the drive unit to ensure that no non-existing DI hardware resource is selected.

"A99.01" fault in inovance MD800 drive indicate "the selected DI hardware resource does not exist". This means a mismatch between the software configuration and the physical hardware setup. It means that the drive is trying to access a digital input (DI) channel that doesn't exist or is not connected correctly.