An attempt has been made to access an I/O device in a manner inconsistent with its current configuration. Either the I/O device is not present in the system or it is configured for some other use. For example if a serial communication line is configured as a network port it cannot be accessed as a user serial line. Make sure the correct device is being accessed. Power down the controller and try starting it again. Make sure the boot disk you are using is valid for your controller. Use the CONFIG_C utility program to make sure the serial I/O configuration is correct. If the problem persists contact Adept Application Engineering for assistance. If the error resulted from a disk I/O operation it indicates that the disk controller hardware is not configured correctly. Adept Customer Service should be contacted in that case.