GE 90-30 PLC, User Manual, Page: 78 / 93

GFK-1322 Appendix D Glossary D-7
D
Name Usually, this refers to the Network Address Name. For Distributed
Directory Protocol operation, this can sometimes refer to a Long-
Form name, which is a combination of a Network Address Name and
a specific Device Name at that network adapter.
Netid The netid is the part of the IP address identifying the network on
which the node resides. (See also Hostid.)
Network An arrangement of nodes and interconnecting branches.
Network Adapter The device, such as the Ethernet Interface, providing
communications services for a particular network.
Network Address Name A character string that is used in lieu of an actual IP address. The
client device uses Name Resolution to resolve this symbolic name
into the actual IP address. This name represents the address on the
network of a particular network adapter.
Node The physical module that connects a node to the network. The
Ethernet Interface is an example of a node. It connects a station (PLC
or CNC) to a network (Factory LAN). A station may contain more
than one Ethernet Interface and therefore contain more than one
node.
Octet A group of 8 bits operated on as a single unit. (See also Byte.)
One-Way Propagation Time See Transmission Path Delay.
Path The sequence of segments and repeaters providing the connectivity
between two DTEs. In CSMA/CD networks, there is one and only
one path between any two DTEs.
Peer Another entity at the same level (layer) in the communication
hierarchy.
Peer-Peer Communication between nodes at the same level or layer in the
hierarchy.
Physical Address The unique physical layer address associated with a particular node
on the Local Area Network (LAN). Ethernet physical addresses are
typically assigned by the manufacturer. (See for comparison, Internet
Address.)
Protocol A set of rules for exchanging messages between two communicating
processes.
Protocol Data Unit (PDU) Information that is delivered as a unit between peer entities of a local
area network (LAN) and that contains control information, address
information, and may contain data.
Remote Station Station located elsewhere on the network. (See also “Local Station”)
Repeater In a Local Area Network, a device that amplifies and regenerates
signals to extend the range of transmission between network nodes or
to interconnect two or more segments.
Responding Station A station which generates a message in response to a command that
was directed to the station.
Round-Trip Propagation Time Twice the time required for a bit to travel between the two most
distant nodes in a bus network.
NOTE: In a network using carrier sense, each frame must be long
enough so that a collision or jam signal may be detected by the
transmitting node while this frame is being transmitted. Its minimum
length is therefore determined by the round-trip propagation time.
Router A device similar to a bridge that allows access to multiple LANs.
(Also known as a gateway in Internet terminology.)