... ) The GSM SMS Controller-Alarm is a very simple device which can be used for authorized door access, controlling gates, switching of ... Automation System, M2M;19. GSM Access Control System, GSM Gate Opener, etc. Mainly Features of the GSM SMS Controller-Alarm RTU42 ... Sensor, Oil Overflow Level Sensor, Water Leak Sensor, Temperature Sensor, Door Sensor, PIR Motion Sensor, Smoke Sensor, Gas Leak Sensor, ...