Specifications

Software Configuration
3–25
3.12 ETHERNET LAN INTERFACE
This section discusses the hardware and software considerations when setting up a network using the
Ethernet LAN interface.
3.12.1 Network Terms
The following are some of the terms used in this section:
 Trunk or network segment—The cable over which network stations communicate. A segment is
usually made up of several cable lengths connected together. A segment is limited in its total length
and the number of network stations it can support. However, a network is not limited to one segment.
 Network trunk —The sum of all the segment cables. Several segments can be interconnected with
repeaters, routers, or bridges to form the network trunk cable.
 Repeater, router, or bridge—Devices that extend the size of a network beyond the limitations of
one segment. These devices not only form a pathway for network signals traveling from one trunk
segment to another; they also regenerate and strengthen network signals.
 Station—Any device that is connected to a network by means of a network interface card. A Little
Board/P5i has the equivalent of an Ethernet network interface card. The Little Board will be a station
on a network when connected via its Ethernet interface.
 Node—Another term for a network station. Each node has its own network interface card (or
equivalent).
 Attachment Unit Interface—(AUI) One of the standard interfaces used to connect a node to the
net, often used between a network interface card and a hub or concentrator.
3.12.2 Twisted-Pair Installations
This section discusses the guidelines for twisted-pair installations.
Cables and Connectors
 Connector jack—You can plug a standard RJ-45-terminated cable directly to the female RJ-45
connector on the Little Board/P5i.
 Connector plug—The RJ-45 connector plugs, attached to both ends of twisted-pair Ethernet cable
lengths, are used to connect the Little Board/P5i to a hub or concentrator.
 Terminators—There are no external termination devices required. Termination is handled
automatically by the hub devices.
Twisted-pair Ethernet cable is 22 or 24 gauge copper wire twisted together in pairs. Ethernet twisted-pair
uses two pairs (four wires), one for transmit, one for receive. It is available from many industry suppliers.
Standard RJ-45 connectors are used for all connections in a twisted-pair cable network.
Twisted-pair Ethernet cables must be 100 meters or less between any node and hub or repeater.