Specifications

Appendix C - Glossary of Terms RS-422 And RS-485 Applications Ebook
Page 122 of 137 Manual Documentation Number: <DocNumber>
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RS-485 Port
Electrical connections that provide two-wire half duplex RS-485 signals or four-
wire full duplex RS-485 signals.
RTS
Request To Send. An RS-232 port handshaking line that is typically asserted
(raised high) to notify another device that the asserting device would like to
transmit data. Is also used in some applications to indicate that the asserting
device is ready to accept data.
Some RS-422 and RS-485 Converters use RTS to enable transmit when
Asserted (RTS High), and in two-wire RS-485 systems to disable receive. When
RTS is low, receive is enabled, transmit is tri-stated off. Special software is
required to use RTS control.
RTU
Remote Terminal Unit
S
SCADA
Supervisory Control And Data Acquisition. It generally refers to an industrial
control system: a computer system monitoring and controlling a process. The
process can be industrial, infrastructure or facility based as described below.
Send Data (SD)
Automatic Send Data control. Circuitry for a RS-485 transmit line driver which
enables the transmit driver for transmit, then returns the transmit driver to a
high impedance tri-state at the end of transmission.