My.Computer.Ports.OpenSerialPort Method

Creates and opens a SerialPort object.

' Usage
Dim value As System.IO.Ports.SerialPort = My.Computer.Ports.OpenSerialPort(portName)
Dim value As System.IO.Ports.SerialPort = My.Computer.Ports.OpenSerialPort(portName ,baudRate)
Dim value As System.IO.Ports.SerialPort = My.Computer.Ports.OpenSerialPort(portName ,baudRate ,parity)
Dim value As System.IO.Ports.SerialPort = My.Computer.Ports.OpenSerialPort(portName ,baudRate ,parity ,dataBits)
Dim value As System.IO.Ports.SerialPort = My.Computer.Ports.OpenSerialPort(portName ,baudRate ,parity ,dataBits ,stopBits)
' Declaration
Public Function OpenSerialPort( _
   ByVal portName As String _
) As System.IO.Ports.SerialPort
' -or-
Public Function OpenSerialPort( _
   ByVal portName As String, _
   ByVal baudRate As Integer _
) As System.IO.Ports.SerialPort
' -or-
Public Function OpenSerialPort( _
   ByVal portName As String, _
   ByVal baudRate As Integer, _
   ByVal parity As System.IO.Ports.Parity _
) As System.IO.Ports.SerialPort
' -or-
Public Function OpenSerialPort( _
   ByVal portName As String, _
   ByVal baudRate As Integer, _
   ByVal parity As System.IO.Ports.Parity, _
   ByVal dataBits As Integer _
) As System.IO.Ports.SerialPort
' -or-
Public Function OpenSerialPort( _
   ByVal portName As String, _
   ByVal baudRate As Integer, _
   ByVal parity As System.IO.Ports.Parity, _
   ByVal dataBits As Integer, _
   ByVal stopBits As System.IO.Ports.StopBits _
) As System.IO.Ports.SerialPort

Parameters

• portName
  String. Required. Name of the port to open.

• baudRate
  Integer. Baud rate of the port.

• parity
  Parity. Parity of the port.

• dataBits
  Integer. Data-bit setting of the port.

• stopBits
  StopBits. Stop-bit setting of the port.

Return Value

An open SerialPort object, configured with the supplied arguments.

Exceptions

The following conditions can cause an exception:

• The portName argument is Nothing or an empty string (ArgumentNullException).

• The baudRate or dataBits argument is zero or negative (ArgumentException).

• The parity argument type is not one of the Parity enumeration values (InvalidEnumArgumentException).

• The stopBits argument type is not one of the StopBits enumeration values (InvalidEnumArgumentException).

Remarks

The My.Computer.Ports.OpenSerialPort method creates and opens a SerialPort object. The arguments to the OpenSerialPort method determine the settings of the SerialPort object.

Your code should close the SerialPort object when it is finished using the object. You can use the Close method to close the object explicitly or the Using statement to close it implicitly. See the example in this topic for more information.

Tasks

The following table lists examples of tasks involving the My.Computer.Ports.OpenSerialPort method.

To	See
Dial a modem attached to a serial port	How to: Dial Modems Attached to Serial Ports in Visual Basic
Send a string to serial port	How to: Send Strings to Serial Ports in Visual Basic
Receive strings from a serial port	How to: Receive Strings From Serial Ports in Visual Basic

Example

This example describes how to send strings to the computer's COM1 serial port.

The Using block allows the application to close the serial port even if it generates an exception. All code that manipulates the serial port should appear within this block, or within a Try...Catch...Finally block with a call to use the Close method.

The WriteLine method sends the data to the serial port.

Sub SendSerialData(ByVal data As String)
    ' Send strings to a serial port. 
    Using com1 As IO.Ports.SerialPort = _
            My.Computer.Ports.OpenSerialPort("COM1")
        com1.WriteLine(data)
    End Using 
End Sub

For more information, see How to: Send Strings to Serial Ports in Visual Basic.

Requirements

Namespace:Microsoft.VisualBasic.Devices

Class:Ports

Assembly: Visual Basic Runtime Library (in Microsoft.VisualBasic.dll)

Availability by Project Type

Project type	Available
Windows Application	Yes
Class Library	Yes
Console Application	Yes
Windows Control Library	Yes
Web Control Library	No
Windows Service	Yes
Web Site	No

Permissions

No permissions are required.

See Also

Tasks

How to: Dial Modems Attached to Serial Ports in Visual Basic

How to: Send Strings to Serial Ports in Visual Basic

How to: Receive Strings From Serial Ports in Visual Basic

Reference

My.Computer.Ports Object

My.Computer.Ports.SerialPortNames Property

System.IO.Ports.Parity

System.IO.Ports.StopBits

System.IO.Ports.SerialPort

Ports.OpenSerialPort

Using Statement (Visual Basic)