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SerialPort.CtsHolding Property

Gets the state of the Clear-to-Send line.

Namespace: System.IO.Ports
Assembly: System (in system.dll)

public bool CtsHolding { get; }
/** @property */
public boolean get_CtsHolding ()

public function get CtsHolding () : boolean

Not applicable.

Property Value

true if the Clear-to-Send line is detected; otherwise, false.

Exception typeCondition


The port is in an invalid state.

- or -

An attempt to set the state of the underlying port failed. For example, the parameters passed from this SerialPort object were invalid.


The stream is closed. This can occur because the Open method has not been called or the Close method has been called.

The Clear-to-Send (CTS) line is used in Request to Send/Clear to Send (RTS/CTS) hardware handshaking. The CTS line is queried by a port before data is sent.

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

.NET Compact Framework

Supported in: 2.0