Abstract: A security alarm system includes a wireless transmitter unit, a portable control unit, and a receiver unit. The transmitter unit includes a sensor for detecting the opening of a door or window to a protected area and an alarm signal generator for providing an alarm signal wherein the alarm signal generator is controlled by the sensor. The control unit includes an arm signal generator for providing and transmitting an arm signal and a disarm signal generator for providing and transmitting a disarm signal. The receiver unit includes an alarm for indicating unauthorized opening of the door or window to the protected area, a first circuit for receiving the alarm signal from the transmitter unit and activating the alarm when the alarm is armed, a second circuit for receiving the arm signal from the control unit and arming the alarm, and a third circuit for receiving the disarm signal from the control unit and disarming the alarm and for turning the alarm off when the alarm is activated.