Rockwell Automation DAG6.5.8 APPLICATION GUIDE SCADA SYSTEM - Manual (Page 406)

Publication AG-UM008C-EN-P - February 2005
2 Glossary
DSR Data-set Ready. A signal from the modem that indicates the
modem is connected, powered up, and ready for data
transmission.
DTE Data Terminal Equipment. Equipment that is attached to a
network to send or receive data, or both. Programmable
controllers, workstations, and interface modules are examples of
DTEs.
DTR Data Terminal Ready. A signal that indicates the transmission
device (terminal) is connected, powered up, and ready to
transmit.
Enhanced PLC-5 Processors A collective name used to refer to PLC-5/11, -5/20, -5/30, -5/40,
-5/60, and PLC-5/80 processors.
EOT End Of Transmission. An ASCII control character that indicates
the end of a data transmission.
Ethernet PLC-5 Processors A collective name used to refer to PLC-5/20E, -5/40E, and -5/80E
processors.
Extended Local PLC-5E™
Processors
A collective name used to refer to PLC-5/40L and -5/60L
processors.
FCC Federal Communication Commission (United States).
Full-Duplex Circuit A physical circuit that allows simultaneous, bidirectional
transmission of data; also called a four-wire circuit.
Full-Duplex Modem A modem that is capable of simultaneous, bidirectional
transmissions.
Full-Duplex Protocol 1) A mode of operation for a point-to-point link with two physical
circuits in which messages or transmission blocks can be sent in
both directions at the same time. 2) Contrasted with two-way
alternate.
General Switched
Telephone Network
International version of a Public Switched Telephone Network.
Half-Duplex Circuit A physical circuit that allows transmission of data in either
direction but not at the same time.
Half-Duplex Modem A modem that sends and receives messages on carriers of the
same frequency. Therefore, simultaneous, bidirectional
transmissions are not possible.