... beam same direction signals of non-interference in each other Alarm: single-beam interrupt call the police operating voltage: ... horizontal plus or minus 15 °, vertical + 15 ° Alarm time: 10 s (optional alarm output time) Response time: 20 ~ 380 ms ms ... wharf, libraries, Banks, power, museums, exhibition halls, schools, farms, alert at the airport, prison security and military stronghold, armory, border ...