This diagram shows one practical way of implementing the control circuitry to generate the three priority sounds. The MSS5M1 is designed so that if more than one priority signal is applied at one time to the device, the higher of the two priority signals will be produced. Mallory Sonalert model number MSS5M1 has one positive terminal (rated at 5 ±0.5 Vdc) and three ground control pins; (-) Low, Medium, and High. The (-) Low pin must be grounded in order to activate any of the three priority sounds. For example, just grounding the (-) Low pin will result in the low priority sound being activated. If the (-) Low and Medium pins are grounded, the medium priority sound will be activated. Finally, if the (-) Low and the High pins are grounded, the high priority sound will be activated. If all three control pins are grounded, only the high priority sound will be activated.