How the Unit Works
© Diebold Election Systems, Inc. 2002 AccuVote-OS Hardware Guide
14
The average life of the battery in the 32KB RAM card is about 10 years. The average battery life
for the 64KB RAM card is approximately 8.5 years. The average battery life for the 128KB RAM
card is about 5.7 years.
3.10. LCD module interface
The AccuVote-OS features a two by sixteen character LCD (Liquid Crystal Display) unit with an
intelligent on-board controller. It is used to display messages and prompts in which each of a
memory’s card’s election modes as well as diagnostic and setup information. LCD prompts are
synchronized with responses provided on the AccuVote-OS YES and NO and buttons, which are
mounted directly on the CPU board and protrude out the front of the enclosure below the LCD.
The LCD is connected by a fourteen-conductor ribbon cable to the CPU board’s P14.
3.11. Printer interface
Each AccuVote-OS contains a light-weight, seven wire dot matrix M-180 Series EPSON printer
controlled directly by the CPU, which prints twenty-four columns on 2¼” wide paper. Both the ink
cartridge and paper roll are easily replaceable using procedures described in the section titled
Pre-Election maintenance
.
The printer is mounted above the CPU board on a small metal bracket and is connected P15 on
the board via a fifteen-conductor flat ribbon cable. All timing and dot matrix information is
controlled by the CPU's program. The printer motor is powered by a 5-volt DC regulator which is
switched on and off by the CPU via a TIP32 transistor. Parallel drivers provide dynamic braking
of the motor whenever the motor power is turned off.
Data to be printed is output via CPU I/O port 0 in the active low state. A strobed hex inverter is
used to pulse the data to the 5-volt printer solenoids which require 3 amps of current when
energized. The solenoids are powered from the 14 volt DC supply, which is set up to emulate the
energy usage required by the solenoids.
3.12. RS232 serial interface
A full duplex serial channel, configured as Data Terminal Equipment (DTE), is provided for
communication with a host computer. The interface requires a flat ribbon cable from the CPU
board’s P10 to a DB9-M (male) connector, which constitutes the main serial port at the rear of the
enclosure. An RS232C cable with a nine-pin female connector is used to connect the main serial
port to the host computer.
3.13. Ballot deflector
A device for deflecting write-in or blank ballots into the alternate compartment in the ballot box is
driven directly from connector P3 on the CPU board.
The deflector motor is driven with 14 volts DC power. Two FET transistors control the motor.
One transistor controls the relay that switches the direction that the deflector moves while the
other transistor toggles the motor power on and off.
3.14. Modems
The AccuVote-OS modem allows you to program memory cards and transmit election results to
the host computer.
The modem is connected to the CPU board with a serial interface. Power is supplied by means
of a connection to the CPU board, which is in turn connected to the power supply. The
Line
and
Phone
jacks at the rear of the AccuVote-OS are connected to the modem by means of RJ-11
