GSM SMS M2M,M2H,RTU,DTU, RTU5011. Name: GSM SMS RTU Alarm System The RTU5011 is a GSM Remote Control and Alarm Unit. It allows you to monitor and control an alarm or remote stations or equipments or machines by SMS. The unit (12 volt powered) is permanently connected to a mobile telephone of GSM type. So it does not require any telephone line of electrical main supply and can be placed anywhere. The remote function can be used to remote control any equipment connected to the unit and the SMS alarm function can inform you the status of the inputs, like which input was triggered and so on.