20100001871 | COMMUNICATION ANOMALY DETECTING DEVICE, AND PASSENGER DETECTING DEVICE - An information request portion receives an information request signal transmitted to an information response portion at its own receiving port. The information request portion comprises at least either a power supply system anomaly determination portion or a ground anomaly determination portion. The power supply system anomaly determination portion determines a short-circuit between a signal line and a power supply system in a case where the information request signal received at the receiving port is always fixed to a H (high) level. The ground anomaly determination portion determines a short-circuit between a signal line and a ground in a case where the information request signal received at the receiving port is always fixed to a L (Low) level. Consequently, the anomaly region of the signal line connects the information request portion and the information response portion so that bidirectional digital communications are possible or the cause of the anomaly is specified. | 01-07-2010 |