Serial communications terminology: In RS-232 handshaking, what does the acronym RTS stand for?

Introduction / Context:
RS-232 serial links use modem control signals for hardware flow control. Recognizing the meaning of common control lines is essential when diagnosing serial device communications and cabling issues.

Given Data / Assumptions:

• The question refers to a standard RS-232 control line.
• Common pairs include RTS/CTS and DTR/DSR.

Concept / Approach:
RTS stands for Request to Send. A Data Terminal Equipment (DTE) device asserts RTS to indicate it wants to transmit; the peer responds with CTS (Clear to Send) if the channel is available. This mechanism prevents buffer overruns and coordinates half-duplex links.

Step-by-Step Solution:

Verification / Alternative check:
Serial breakout boxes and protocol analyzers label RTS as Request to Send; driver settings reference RTS/CTS flow control.

Why Other Options Are Wrong:
They are unrelated phrases and not RS-232 nomenclature.

Common Pitfalls:
Confusing RTS with CTS or with DTR/DSR, which serve different roles (data terminal ready / data set ready).

Final Answer:
Request to send