Disclosed is a multi-display apparatus including display modules and a sensor. Some of the display modules sequentially connected receive a signal from the sensor, and each of the display modules transmits signals including the signal from the sensor to a display module connected to a rear stage thereof. The display module connected to a final stage transmits the signal from the sensor to a control box. The control box includes a detector configured to detect whether signals from a plurality of transmission lines include a generated flag signal based on the signals including a signal from the sensor and a selector configured to select a transmission line detected as including the flag signal by the detector and set the selected transmission line as a channel for communication with the sensor.