PURPOSE: To integrate the alarm system, to reduce the cost of circuit construction and the circuit rent, and to execute the centralized control of crime prevention and prevention of disasters, in the sales management system for transferring various data by connecting a host computer of a head office and an electronic cash register of a branch office by a communication circuit.

CONSTITUTION: To the sales management system constituted by connecting a host computer 1 and plural electronic cash registers 2 by a communication circuit 4, an alarm system consisting of a crime prevention/disaster prevention sensor control part 5 for connecting various sensors 6a-6c is connected, and when an abnormal state is generated, an alarm notice is the host computer 1 through the communication circuit of the sales management system, it is reported to a security company, and also, communication to the persons concerned is executed simultaneously.