Download Modicon M580 - Hardware - Reference Manual

Glossary
switch
A multi-port device used to segment the network and limit the likelihood of collisions. Packets are
filtered or forwarded based upon their source and destination addresses. Switches are capable of
full-duplex operation and provide full network bandwidth to each port. A switch can have different
input/output speeds (for example, 10, 100 or 1000Mbps). Switches are considered OSI layer 2
(data link layer) devices.
T
T->O
(target to originator) See target and originator.
target
In EtherNet/IP, a device is considered the target when it is the recipient of a connection request for
implicit or explicit messaging communications, or when it is the recipient of a message request for
un-connected explicit messaging.
TCP
(transmission control protocol) A key protocol of the internet protocol suite that supports
connection-oriented communications, by establishing the connection necessary to transmit an
ordered sequence of data over the same communication path.
TCP/IP
Also known as internet protocol suite, TCP/IP is a collection of protocols used to conduct
transactions on a network. The suite takes its name from 2 commonly used protocols: transmission
control protocol and internet protocol. TCP/IP is a connection-oriented protocol that is used by
Modbus TCP and EtherNet/IP for explicit messaging.
TFTP
(trivial file transfer protocol) A simplified version of file transfer protocol (FTP), TFTP uses a clientserver architecture to make connections between 2 devices. From a TFTP client, individual files
can be uploaded to or downloaded from the server, using the user datagram protocol (UDP) for
transporting data.
TIME_OF_DAY
See TOD.
TOD
(time of day) The TOD type, encoded in BCD in a 32-bit format, contains this information:
 the hour encoded in an 8-bit field
 the minutes encoded in an 8-bit field
 the seconds encoded in an 8-bit field
NOTE: The 8 least significant bits are not used.
The TOD type is entered in this format: xxxxxxxx: TOD#<Hour>:<Minutes>:<Seconds>
EIO0000001578 10/2013
297