Specifies the type of change that occurred on the System.IO.Ports.SerialPort object.
This enumeration is used with the SerialPort.PinChanged event.
A serial port pin changes state when it is asserted or unasserted.
A break was detected on input.
The Carrier Detect (CD) signal changed state. This signal is used to indicate whether a modem is connected to a working phone line and a data carrier signal is detected.
The Clear to Send (CTS) signal changed state. This signal is used to indicate whether data can be sent over the serial port.
The Data Set Ready (DSR) signal changed state. This signal is used to indicate whether the device on the serial port is ready to operate.
A ring indicator was detected.