Panasonic DP2000 User Manual
Page 39
30/05/02
Document Systems Support V1.0
39
TOKEN PASSING:
This is a method of controlling access to a network using a special data
packet called a TOKEN from node to node. When all the stations are idle,
the TOKEN is labelled as '
free
'. A station wishing to transmit data waits for
a '
free
' TOKEN, then changes the token to '
busy
' and transmits a data
packet immediately behind it. When the station for which the information
was for has removed it from the network, the TOKEN is then released.
With TOKEN PASSING, workstations or applications can be assigned
priorities, either giving them preferential claim on a circulating TOKEN, or
defining the amount of data they can transmit when they receive a
TOKEN. (See
Token Ring
)
TOKEN RING:
A network type using a RING TOPOLOGY and TOKEN PASSING to control
access.
TREE TOPOLOGY:
A network consisting of a branching cable with no closed loops. The TREE
layout begins at a point known as the 'HEAD END' and continues to a
series of POINT to POINT links. See
TABLE 1
TWISTED PAIR:
Cable that is made up of 2(two) insulated copper wires arranged in a
regular helix shape. Each wire pair acts as a single communication link. A
typical cable consists of a
number of these pairs of wires. Basic Twisted Pair is sometimes known as
Unshielded Twisted Pair (UTP).
UNI: (User Network Interface)
The demarcation point between a LAN and a public data network (WAN)
UNIX:
This is a powerful multitasking operating system for computers running
complex applications.
UPS: (Uninterruptable Power Supply)
A device that will keep up a computer system or any other electrical
device for a period of time in the event of a power failure.