Patent ID: 9691267
Date: 2017-06-27
CPC Classifications: G08B,H04B

Claim:
1. An environment sensing system including an isolator coupled to a bi-directional communication loop having a communication recovery function, the environment sensing system comprising: a communication loop including a first line and a second line; an interface unit which includes a loop A terminal connected to one end of each of the first line and the second line and a loop B terminal connected to another end of each of the first line and the second line, outputs a predetermined operating voltage and a digital call signal calling a specific device, through the first line by using at least one of the loop A terminal and the loop B terminal, receives a change in an electric current on the second line by using at least one of the loop A terminal and the loop B terminal, and then converts the change in the electric current into a received signal; a plurality of sensors which are connected to the first line and the second line, are operated by the operating voltage from the first line, and generate a measurement value by sensing an environment state, and transmit an address data and the measurement value of the sensors by changing electric current of the second line in response to the digital call signal; an isolator configured to be connected to at least one of the first line and the second line, to maintain the lines in a normal connection state in case of a normal situation and to convert a short state into an isolation state by disconnecting at least one of the first and the second lines in case of an abnormal state in which part of the first line and the second line of the communication loop are shorted; and a main control panel configured to provide the digital call signal for calling at least one of the plurality of sensors to the interface unit and to determine an environment state around the at least one of the plurality of sensors based on the measurement value extracted from the received signal of the interface unit.