Specifications

Appendix C - Glossary of Terms RS-422 And RS-485 Applications Ebook
Page 103 of 137 Manual Documentation Number: <DocNumber>
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Characteristic Impedance (ohms)
A value based on the inherent conductance, resistance, capacitance and
inductance of a cable that represents the impedance of an infinitely long cable.
When the cable is cut to any length and terminated with this characteristic
impedance, measurements of the cable will be identical to values obtained
from the infinite length cable. That is to say that the termination of the cable
with this impedance gives the cable the appearance of being infinite length,
allowing no reflections of the transmitted signal. If termination is required in a
system, the termination impedance value should match the characteristic
impedance of the cable.
Converters
A device that converts electrical signals from one format into another.
Conversions are electrical, electrical to light (for fiber optical cable), Infrared
light or RF.
CTS
Clear To Send - the handshaking line asserted by a DCE device to indicate to a
DTE device that it can accept data. The DTE device sets the RTS line, the DCE
reads the RTS line to know if the other device can accept data.
D
Data A (RS-485)
The A data line in a half duplex two-wire RS-485 system. Some manufacturers
label Data A as Data(-). In an RS-485 two-wire network, Data A is created by
connecting the Transmit Data A (TDA) and Receive Data A (RDA) lines.
Data B (RS-485)
The B data line in a half duplex two-wire RS-485 system. Some manufacturers
label Data B as Data(+). In an RS-485 two wire network, Data B is created by
connecting the Transmit Data B (TDB) and Receive Data B (RDB) lines.