Provides response entry confirmation and positive acknowledgment that the Base Station received the response input. Power and Power Management Powered by a commonly available 9-volt alkaline battery and internally regulated to 5 volts for consistent performance throughout the life of the battery. Keypad is using power only when transmitting and acknowledging an entered response. Low battery is indicated by the rapidly flashing seven-segment LED display when about 100 responses are remaining. Battery provides sufficient power for 10,000 response interrogations before requiring replacement.
Keypads operate independently of each other, and keypad addresses are programmable.
Response entries are acknowledged when received by the Base Station. Integrated error checking ensures accurate communication of responses and control functions. The keypad design uses separate frequencies for controlling the keypad and communicating key presses to the Base Station. This receiver is dual conversion crystal referenced frequency modulated. A 345 MHz RF keypad transmitter sends keypress information to the Base Station's receiver.