IN-VEHICLE CONTROL NETWORK DEVICE

PROBLEM TO BE SOLVED: To provide an in-vehicle control network device capable of simplifying the constitution of the device without losing the reliability of control by solving a problem concerned with the extension of a backup power supply. SOLUTION: In the in-vehicle control network device constituted by connecting non-backup type control devices 2-4 in which data in data memories disappear when power from an external power source is interrupted and a backup type control device 1 in which data in a data memory do not disappear even when power from the external power source to the control devices 2-4 is interrupted, important data stored in the data memories built in the non-backup type control devices 2-4 are backed up to the backup type control device 1 periodically or immediately before service interruption, and after restoring from the service interruption, the backed-up data are rewritten in the data memories of the control devices 2-4. COPYRIGHT: (C)2004,JPO