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 will turn off automatically approximately 5 minutes after last entry to conserve battery life. Battery provides sufficient power for 1000 hours operation. Microcontroller utilizes 'sleep' mode to extend battery life. Keypad will store answers almost indefinitely.
Answers remain securely stored in keypad until a clear keypad command is received.
Docking station accepts the responses from each keypad and delivers them to the attached computer via a standard RS-232 serial cable. Transfer of answers from a keypad to the docking station is done through proximity downloading. This type of data transfer requires no contact or wires between the keypad and the docking station. Data is passed to the attached computer at 9600 baud. Checksum error checking is used to ensure data integrity.