SerialPort.CtsHolding Property


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

 property bool CtsHolding { bool get(); };
public bool CtsHolding { get; }
public bool CtsHolding { get; }
member this.CtsHolding : bool
member this.CtsHolding : bool
Public ReadOnly Property CtsHolding As Boolean

Property Value


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



The port is in an invalid state.


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.

Applies to