Specifications

October 8, 2003 Networking Alpha Signs (9700-0112C)
68 Glossary
Character height (rows) times the pitch equals the height of the characters. For example, for an Alpha 215 sign,
7 rows times 0.3 inches is equal to 2.1 inches.
characters per line
Determined by the number of pixels across the sign and by the size of the character. A normal character is 5
pixels wide with one pixel space separating characters. Thus, an 80 column sign can display 13 characters (80/6=
13.3).
NOTE: As you plan your sign requirements, write down the messages you intend to display on the sign.
Count the characters in the words that you use most often. How many words you want to see at once
determines the number of characters per line required by your application. If a word will not fit on the
line, the word displays one character at a time or it starts a new line, depending on the display mode
being used.
checksum
A numeric computation using the bits of a transmitted message, and the resulting value. The value is
transmitted with the message, and the receiving device recalculates the checksum, then compares it to the received
value to detect transmission errors.
chip
A small device found on the microboard of an LED sign. Contains a program (RAM or EPROM, for example)
that runs the sign.
circuit
Any path that can carry an electrical current.
client
Software program or node that requests services from a server.
clusters
Multiple LEDs assembled in groups that together form one bright pixel point when lit. The LEDs are
connected to a molded cup which is then filled with clear epoxy to hold the LED in place. Clusters may contain one
color LED or, in a multi-color application, a combination of different colors.
CM
Character Matrix. Displays characters only (not graphics) in discrete blocks of LEDs.
coaxial cable
A type of cable that uses two conductors: a central, solid wire core surrounded by insulation and, surrounding
that, a braided wire conductor sheath.
code
Specific firmware or software containing instructions for a computer or sign.
color
Adds interest and contrast over a monochrome, red-only sign. For simple informational signs, red is often
sufficient. The green and amber colors are considered softer colors and may be more appropriate for some
environments. Color signs can be 3 color, (red, amber, and green), 9 color, (additional shades of red, amber, and
green), 256 color (usually RGB or CMYK), 262,000, or 4,000,000 for full color displays. Some signs allow you to set
the color of the background or the foreground. In a red-only sign model, this would allow red text on a black
background or black text on a red background. In a multi color sign, you could have a variety of text colors and a
variety of background colors.