GE 90*-30 PLC Series User Manual page 75

D
D-4
Channel Status Bits
Client
Collision
Collision Domain
Command Dictionary
Command Field
Communications Window
Connection
CSMA/CD
Data Communications Equipment
(DCE)
Data Link Layer
Data Terminal Equipment
DCS Words
Detailed Channel Status Words
Device Name
Directory Information Base (DIB)
Distributed Directory Protocol
(DDP)
Domain Name System (DNS)
Dotted Decimal
Dynamic Host Configuration
Protocol (DHCP)
Series 90™-30 PLC LONWORKS® Bus Interface Module User's Manual – June 1997
The Channel Status bits comprise bits 17–80 (64 bits) of the status
indication area. These bits consist of an error bit and a data transfer
bit for each of the channels that can be established
A node that requests network services from a server. A client PLC
initiates a communications request. (See also Server.)
A condition that results from concurrent transmissions by two or
more nodes on the transmission medium.
A single CSMA/CD network. If two or more nodes are within the
same collision domain and both transmit at the same time, a collision
will occur. Nodes separated by a repeater are within the same
collision domain. Nodes separated by a bridge are within different
collision domains.
Provides an alphabetical listing of the LAN Interface commands.
That part of a protocol data unit (PDU) that contains commands, as
opposed to the address field and information field.
A part of the PLC scan that provides an opportunity for the LAN
Interface to read and write PLC memory. The window is executed
automatically once per PLC scan.
A logical communication link established between two end points
and used to transfer information.
See Carrier Sense Multiple Access with Collision Detection.
Examples: Modems and transceivers. Distinct from DTE, Data
Terminal Equipment.
In Open Systems Interconnection architecture, the layer (Layer 2)
that provides services to transfer data over a physical link between
open systems. Consists of the LLC and MAC sublayers.
Examples: computers, terminals, printers. Distinct from DCE, Data
Communications Equipment.
See Detailed Channel Status Words.
Two status words containing detailed information on a single Series
90 channel. The DCS words are retrieved using the Retrieve Detailed
Channel Status Command.
A character string that identifies a particular communication
destination at a given network adapter ( for example, the PLC CPU
or an SNP gateway).
A collection of information used for directory services (like name
resolution). In this document DIB refers to the DDP database which
is actually distributed among all DDP devices instead of in a single
name server. (See also Distributed Directory Protocol (DDP).
The GE proprietary protocol used to provide distributed name
service on a TCP/IP Ethernet network. The distributed nature of
DDP means that there is no name server.
The predominant name service protocol used by the Internet. DNS is
primarily used to resolve a name into an IP address.
The notation for IP, gateway, and name server addresses as well as
the subnet mask. It consists of 4 decimal numbers (0–255) separated
by periods. Example IP address: 3.0.0.1
A superset of the BOOTP protocol (see BOOTP).
GFK-1322A