Specifications

October 8, 2003 Networking Alpha Signs (9700-0112C)
78 Glossary
protocol
A set of rules for transmitting data within a network or internetwork. Specifies the format, timing, and
sequence in which the network transmits data. Common protocols include AFP, ALAP, RTMP, NCP, IPX.
reader board
An electronic sign that combines text and graphics to convey a fixed or changeable, moving or unmoving
advertising or locational message. See also electronic display.
record
A collection of related fields, such as all the information about one display command.
repeater
Used to boost the electrical signal along very long networks.
resolution
The quality and clarity of text and graphics, defined by the pixel diameter and center-to-center spacing of the
character displayed. The closer the pixels are to each other, the higher the resolution of the character. Low
resolution characters are designed for distance viewing. Also known as density.
rev
Revision.
RF transmitter
Radio frequency transmitter. Wireless device which sends a message from a network computer and modem to
a data receiver.
routing
The transmission of a datagram from one node to another on the same or a different network. Refers to the
paths that are chosen to transmit an IP datagram from its origin to its destination, based on the IP addresses
contained in the datagram.
RS232
Uses serial communication, specifically RS232 protocol. Connects a sign directly to a computer. Limited to a
distance of 50 feet and connects only one sign to one computer.
RS232/RS485 jumper
A set of three small prongs inside some signs with a connector that covers only two of the three prongs
(jumper). Determines whether the sign is using RS232 or RS485 communication.
RS485
Uses parallel communication, specifically RS485 protocol. Connects multiple signs directly to a computer for
distance longer than 50 feet. Requires a converter box.
RTC
Real-time Clock. A memory chip that allows a sign to retain accurate time while not powered. Runs from a
battery.
serial
An RS232, RS485, or USB connection between a PC and one or more computers in a network.
serial address