A
A-2 TCP/IP Ethernet Communications User’s Manual - August 1997 GFK-1084B
PC Personal Computer , IBM compatible
PDU Protocol Data Unit
PLC Programmable Logic Controller
RAM Random Access Memory
SQE Signal Quality Error
SRTP Service Request Transfer Protocol
TCP Transmission Control Protocol
TCP/IP Transmission Control Protocol/Internet P rotocol
UDP User Datagram Protocol
Glossary of Terms
AAUI Port The connector on the network interface.
AAUI Cable The cable between the AAUI port and the transceiver (some transceivers
plug directly into the AAUI port, thus requiring no separate A AUI cable).
Address Administration The assignment of LAN addresses locally or on a universal
basis.
Address Field The part of a Protocol Data Unit (PDU) that contains an address.
Address Resolution Protocol The Internet Protocol that binds dynamically a high-level
Internet Address to a low-level physical hardware address such as a MAC address.
Apple Attachment Unit Interface (AAUI) A lower power, smaller connector adaptation
of the IEEE 802.3 AUI.
ASCII Code The American Standard Code for Information Interchange is an
information code standard by which digits, letters, symbols and control characters
can be encoded as numbers.
Attachment Unit Interface (AUI) In a network node on a Local Area Network, the
interface between the medium attachment unit (MAU) and the data terminal
equipment. Often called “transceiver cable”.
Bit Contraction of Binary Digit. The smallest unit of memory. Can be used to store one
piece of information that has only two possible states or values (e.g., One/Zero,
On/Off, Yes/No). Data that requires more than two states or values (e.g., numerical
values) requires multiple bits (see Word).
BOOTP BOOTP is a bootstrap protocol that allows a TCP/IP network node (such as a
Series 90 PLC with Ethernet Interface) to discover its own IP address, the address of
a file server host, and the name of a file to be loaded into memory and executed.
Broadcast Address A LAN group address that identifies the set of all nodes on a Local
Area Network.
Bridge A functional unit that interconnects two Local Area Networks (LANs) that use
the same logical link control protocol, but may use different medium access control
protocols.
Broadcast Sending of a frame that is intended to be accepted by all other nodes on the
same Local Area Network.
Bus Network A Local Area Network in which there is only one path between any two
network nodes and in which data transmitted by any node is available to all other
nodes connected to the same transmission medium. NOTE: A bus network may be
linear, star, or tree topology.