Auxiliary unit for sensor units

An auxiliary unit for sensor units connected to a plurality of sensor units via a plurality of detection signal lines through which the plurality of sensor units output a detection result of each of the plurality of sensor units and a communication line for communicating with the plurality of sensor units, the auxiliary unit for sensor units comprising:

• a receiving unit configured to communicate with each of the plurality of sensor units via the communication line and receive warning information transmitted by at least one of the plurality of sensor units;
• a common output line for outputting the warning information to an external device when receiving the warning information from at least one of the plurality of sensor units via the communication line;
• and
• a plurality of individual output lines for individually outputting a detection result of each of the plurality of detection signal lines to the external device.