VEHICLE-USE MULTIPLEX COMMUNICATION EQUIPMENT

摘要

PROBLEM TO BE SOLVED: To provide the vehicle use multiplex communication equipment to prevent deterioration in the reliability of the system due to a fault of a multiplex communication input or/and output circuits or the like. SOLUTION: A standby multiplex communication output circuit 6f and a standby multiplex communication input circuit 6g in parallel with a multiplex communication output circuit 6c and a multiplex communication input circuit 6d are connected to a standby multiplex communication output terminal T×2 and a standby multiplex communication input terminal R×2 of a CPU 6b in common use for a transmission line state discrimination means. The multiplex communication output circuit 6c and the multiplex communication input circuit 6d are connected to a transmission line 5 via a contact A of a changeover means 6h. The standby multiplex communication output circuit 6f and the standby multiplex communication input circuit 6g are connected to the transmission line 5 via a contact B of the changeover means 6h. An output port P0 of the CPU 6b is connected to a drive circuit 6i controlling the contact changeover of the changeover means 6h.