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Glossary
Pixel:
A group of LEDs that turn on and off to form the characters and graphics making up the
message content.
Power Supply:
Unit that converts incoming AC power to DC power as required by several
components within the display.
Power Supply Group:
2 power supplies that provide redundant power to multiple modules within
its load capacity.
Relay:
An electromechanical or semiconductor switch in which a current or voltage applied across
one port or terminal controls electrical currents or voltages that appear across another terminal or
terminals.
Row:
Horizontal line of pixels.
RS232:
Standard PC communication type with a maximum cable length of 25' (7.62 m).
RS422:
Standard differential communication type with a maximum cable length of 4,000'
(1.2 km).
Serial Port:
Connector on the back of the control computer that controls the display network through
either a 9- or a 25-pin serial connector.
VFC-3000 Controller:
A component that receives signal information from the central controller,
translates it, and activates the appropriate pixels on the display. It retains messages in its memory,
determines the appropriate display brightness, and keeps the date and time through an internal
clock/calendar. The VFC-3000 controller also reads and analyzes the diagnostic data from a variety of
sensors. It is located in either the traffic cabinet or the display.
