METHOD FOR UPGRADING IMAGE FILE IN NETWORK SYSTEM

摘要

PURPOSE: A method for upgrading an image file in a network system is provided to use a main controller recognizing states of sub controllers for upgrading instead of an operator, so as to select an upgrade method suitable for network system characteristics and eliminate troubles and mistakes of the operator. CONSTITUTION: A main controller downloads a new image file of a high version to a sub controller(701). The sub controller copies the image file downloaded from the main controller to a specific area discriminated from an area storing a previous image file in a flash memory(703). The main controller initializes the sub controller(704), to enable the sub controller to perform an initialization operation(705). The sub controller copies the new image file stored in the specific area of the flash memory to a RAM(Random Access Memory), deletes the image file, and executes the image file in the RAM(706-710). Whether the new image file is normally operated is checked(711). If so, the previous image file stored in the flash memory is updated to the new image file of the RAM(712). If not normally operated, the step 705 is returned to initialize the sub controller. If the new image file does not exist in the specific area of the flash memory, the previous image file stored in the flash memory is copied to the RAM(707).