... System, M2M;19. GSM Access Control System, GSM Gate Opener, etc.Mainly Features of the GSM SMS Controller-Alarm: 1 relay ... Overflow Level Sensor, Oil Overflow Level Sensor, Water Leak Sensor, Temperature Sensor, Door Sensor, PIR Motion Sensor, Smoke Sensor, Gas Leak Sensor, Glass Break Sensor, Shock Sensor, Power failure sensor, etc.The PC ...