| 摘要 |
PROBLEM TO BE SOLVED: To provide a connection diagnosis circuit which can diagnose a connection state between devices separately from normal operation without adding an interface signal between the devices. SOLUTION: The present connection diagnosis circuit is configured so that a device 1 is connected to a device 2 by power source supply signals (power source signals 7VA, 7VB and 7VC and ground signals 7GA, 7GB and 7GC) and cables 3A, 3B and 3C having a path for a logic signal, and the power source is supplied thereto from the device 2 by the power source supply signals. The device 1 has a diagnosis circuit 5 which diagnoses connection with the device 2. In the case where the cables 3A, 3B and 3C are disconnected, the diagnosis circuit 5 reverses the levels of the power source supply signals used for connection diagnosis, and inputs the signals into a comparator 9; and this comparator 9 compares the levels of the power source supply signals with an expected value when the power source supply signals are normally connected, and, even if one inconsistency is found, regards the signal as a signal for reporting a connection error. COPYRIGHT: (C)2005,JPO&NCIPI
|
