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Rockwell Automation DAG6.5.8 APPLICATION GUIDE SCADA SYSTEM User Manual

Page 409

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Publication AG-UM008C-EN-P - February 2005

Glossary 5

RXD

Received Data. A serialized data input to a receiving device.

Remote Station

A device (programmable controller with I/O modules) that is
located in a remote site away from the master station and that
controls I/O points at the remote site. A remote station accepts
commands from and can send data (if capable) to a master station
via a telemetry network.

SCADA

Supervisory Control and Data Acquisition

Slave

See remote station.

Slave Protocol

See Half-Duplex Protocol.

Serial Port

An electrical connection on a computer that handles data bits one
after another; the communications port (COM1 or COM2) to
which devices such as a modem, a mouse, or a serial printer can
be attached.

Spurious Character

A false or unexpected character received when none is expected.

Standard Radio Modem

A standard radio modem is an assembly that contains both a radio
and a modem, which transmits data without any special handling.
Data error checking is the responsibility of the receiving station
(DTE).

Station

Any programmable controller, computer, or data terminal
connected to, and communicating by means of, a data channel; a
device on a network.

Station Addressing

The syntax allowing packets to be routed correctly between
master and remote stations.

Synchronous Transmission

A type of serial transmission that maintains a constant time
interval between successive events.

Telemetry

Transmission and collection of data obtained by sensing real-time
conditions.

Topology

The way a network is physically structured. Example: a ring, bus,
or star configuration.

Transceiver

An electronic device that operates as both a radio transmitter

and receiver.

TXD

Transmitted Data. An output from the module that carries
serialized data.