Patent ID: 8686833

Claim:
A control system comprising: a plurality of sensor apparatuses each including a sensor, an output circuit connected to the sensor, and a communication device; and an electronic control apparatus to which the communication devices of the sensor apparatuses are connected through a common communication line to enable data communication between the electronic control unit and each of the sensor apparatuses, the electronic control apparatus being connected to signal lines respectively connected to the output circuits of the sensor apparatuses to enable receiving sensor signals respectively outputted from the sensor apparatuses, the electronic control apparatus including a transmission control means configured to, prior to transmitting communication data to one of the sensor apparatuses, set the signal lines connected to the other sensor apparatuses to which the communication data is not addressed in an enabled state in which the sensor signal is allowed to be transmitted, and set the signal line connected to the one of the sensor apparatus to which the communication data is addressed in a disabled state in which the sensor signal is inhibited from being transmitted, each of the sensor apparatuses including a determination means to determine whether or not the signal line connected to the own sensor apparatus is in the disabled state based on an operation state of the output circuit of the own sensor apparatus, and a reception control means configured to accept the communication data received in the communication device to perform an operation in accordance with the accepted communication data when the signal line connected to the own sensor apparatus is determined to be in the disabled state by the determination means, and discard the received communication data when the signal line connected to the own sensor apparatus is determined to be in the enabled state by the determination means; wherein the output circuit is a buffer circuit constituted of an operational amplifier including at an input stage thereof a differential amplifier loaded with a current mirror circuit and inputted with an output of the sensor and an output of the operational amplifier, and the determination means is configured to determine whether or not the signal line is in the disabled sate based on an voltage of an output node of the input stage.