Communication anomaly detecting device, and passenger detecting device

An occupant detector, comprising:

• at least one load sensor for acquiring load information according to a load applied to a seat and
• a control device connected to the load sensor in such a manner that bidirectional digital communications are possible through a signal system line,
• wherein, when the control device transmits an information request signal to the load sensor, the load sensor receives the information request signal, and the load sensor transmits a load information signal including the load information in response to the received information request signal, and the control device receives this load information signal and performs an occupant determination,
• the occupant detector comprising:
• the control device and
• first and second power supply system lines for supplying electricity to the load sensor through the control device, and the potential of the first power supply system line is higher than the potential of the second power supply system line,
• wherein the control device comprises a switching element and a pull-up resistor, and wherein the switching element comprises a first terminal connected to the signal system line, a second terminal connected to the second power supply system line, and a control terminal for inputting the information request signal, and wherein the pull-up resistor has one end connected to the first power supply system line and another end connected to the signal system line, and
• wherein the load sensor comprises a switching element comprising a first terminal connected to the signal system line, a second terminal connected to the second power supply system line, and a sensor side control terminal for inputting the load information signal.