FIRE AND GAS DETECTION SYSTEM HAVING BIDIRECTIONAL COMMUNICATION FUNCTION TO BE INSTALLED IN DANGEROUS REGION

A fire and gas detection system, which has a bidirectional communication function and is to be installed in a dangerous region, according to the present invention, comprises: a first terminal block and a second terminal block; a +line and a −line; a first loop line wherein a part of a loop shape thereof is arranged to extend over a dangerous region having a relatively high dangerousness of disaster occurrence and the other part of the loop shape is arranged in a safe region other than the dangerous region, and a second loop line arranged in parallel to the first loop line in the same shape; a first connection line and a second connection line; a barrier which is installed in the first connection line and the second connection line and disconnects the first connection line and the second connection line when short-circuiting between the first loop line and the second loop line is detected; a sensor connected to the first loop line and the second loop line inside the dangerous region; and a CPU which simultaneously controls the first and second terminal blocks to modulate and output call information designating a sensor at a first voltage and demodulate detection information from a second voltage, and performs fire and gas detection warning processing in accordance with the demodulated detection information.