User manual

Publication 1734-UM011A-EN-P - February 2004
Preface 6
Terminology
Refer to the table below for the meaning of common terms.
This term Means
BootP BootP (Bootstrap Protocol) is a low-level protocol that provides
configurations to other nodes on a TCP/IP network. BootP
configuration files let you automatically assign IP addresses to an
Ethernet module (you can also obtain Subnet masks and gateway
addresses from BootP).
bridge A node between two similar communication subnets where protocol
translation is minimal.
CIP Control and Information Protocol, the EtherNet/IP application layer
uses the “producer/consumer” networking model. In this model one
producer broadcasts (multicasts) the data once to all the consumers.
All consumers see the data simultaneously and may choose whether
to consume (receive) the data or not. Delivery time is consistent, no
matter how many consumers there are.
connection The communication mechanism from the controller to another
module in the control system, usually used to exchange I/O data.
consumer A destination device in the CIP networking model. See CIP.
CSMA/CD Carrier Sense Multiple Access/Collision Detection is the access
method used in Ethernet. When a device wants to gain access to the
network, it checks to see if the network is quiet (senses the carrier).
If it is not, it waits a random amount of time before retrying. If the
network is quiet and two devices access the line at exactly the same
time, their signals collide. When the collision is detected, they both
back off and each waits a random amount of time before retrying.
determinism The ability to predict when information will be delivered. Important in
time critical applications.
DHCP The Dynamic Host Configuration Protocol is an Internet protocol,
similar to BootP, for automating the configuration of computers that
use TCP/IP. DHCP can be used to automatically assign IP addresses,
to deliver IP stack configuration parameters, such as the subnet mask
and default router, and to provide other configuration information,
such as the addresses for printer, time and news servers.
The 1734-AENT factory default is DHCP enabled. Upon powerup, the
module sends a message containing its hardware address to any
DHCP server on the network. The server(s) replies by sending a
message with an appropriate IP address for the adapter. The adapter
responds by acknowledging to a server that it will use the offered IP
address.
DNS The Domain Name System is a hierarchical, distributed method of
organizing the name space of the Internet. The DNS administratively
groups hosts into a hierarchy of authority that allows addressing and
other information to be widely distributed and maintained. A big
advantage to the DNS is that using it eliminates dependence on a
centrally-maintained file that maps host names to addresses.
Ethernet A physical layer standard using Carrier Sense Multiple Access with
Collision Detection (CSMA/CD) methods.
EtherNet/IP Ethernet Industrial Protocol applies a common application layer (CIP)
over Ethernet by encapsulating messages in TCP/UDP/IP.