Serial Port Vs Mscomm
With Vb express 2008, runnig of serialport (oncomm event) is slower than mscomm under vb6.make a simple test: - soft1 send a message to soft 2 through serial com - soft2 received oncomm event, then send a message to soft 1. And so on Now develop one version of soft 2 under vb6 with mscomm. Visual Basic Serial COM Port Tutorial (Visual Studio 2010) - Part 2 Kelvin Le. Unsubscribe from Kelvin Le? Cancel Unsubscribe. Subscribe Subscribed Unsubscribe 4K.
Is it possible that .Net SerialPort and VB6 MSComm work different?
In both cases, I´m reading data from the buffer, and both got me different strings, if I import the MSComm dll into my .Net project, It works perfectly (obviously).
Does anyone have more in deep information?
If it helps, here are my to simple samples, in both cases I send the same Byte Array..
VB6:
c#
Charles3 Answers
You are mixing bytes and strings. MSComm was very lax about it but SerialPort cares about text encoding. Clearly you are using a binary protocol, it is likely that your received string is containing question marks for bytes that could not be converted to the SerialPort.Encoding (default is ASCII). You have to use the Read() method to get the response.
Hans PassantSerial Port Vs Mscomm 2016
Hans PassantI expect that they both use the underlying O/S API; but I guess that they may each use that API in difference ways: e.g. with different default COM port parameters (if you don't specify the parameters explicitly).
Another difference may be in the timing: when you read the input/reply, how do you know whether it's been sent yet, and how do you know whether the 'read' or 'input' function is waiting for long enough?
ChrisWChrisWMSComm and Serialport are free gifts and have not many in common. A well known portable library that spares you from the troubles is SuperCom. It offers a MSComm compatible ActiveX and also a A NET class library. One can use the one that fits better. It can be used with C++, Delphi, VB6, VB net, C#, FreePascal, Perl, Java, and many more. And it is fully compatible to 32 bit and 64 bit of Windows incl. Windows XP,7,8,10.
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-->Definition
Examples
The following code example demonstrates the use of the SerialPort class to allow two users to chat from two separate computers connected by a null modem cable. In this example, the users are prompted for the port settings and a username before chatting. Both computers must be executing the program to achieve full functionality of this example.
Remarks
Use this class to control a serial port file resource. This class provides synchronous and event-driven I/O, access to pin and break states, and access to serial driver properties. Additionally, the functionality of this class can be wrapped in an internal Stream object, accessible through the BaseStream property, and passed to classes that wrap or use streams.
The SerialPort class supports the following encodings: ASCIIEncoding, UTF8Encoding, UnicodeEncoding, UTF32Encoding, and any encoding defined in mscorlib.dll where the code page is less than 50000 or the code page is 54936. You can use alternate encodings, but you must use the ReadByte or Write method and perform the encoding yourself.
You use the GetPortNames method to retrieve the valid ports for the current computer.
If a SerialPort object becomes blocked during a read operation, do not abort the thread. Instead, either close the base stream or dispose of the SerialPort object.
Constructors
SerialPort()SerialPort()SerialPort()SerialPort() | Initializes a new instance of the SerialPort class. |
SerialPort(IContainer)SerialPort(IContainer)SerialPort(IContainer)SerialPort(IContainer) | Initializes a new instance of the SerialPort class using the specified IContainer object. |
SerialPort(String)SerialPort(String)SerialPort(String)SerialPort(String) | Initializes a new instance of the SerialPort class using the specified port name. |
SerialPort(String, Int32)SerialPort(String, Int32)SerialPort(String, Int32)SerialPort(String, Int32) | Initializes a new instance of the SerialPort class using the specified port name and baud rate. |
SerialPort(String, Int32, Parity)SerialPort(String, Int32, Parity)SerialPort(String, Int32, Parity)SerialPort(String, Int32, Parity) | Initializes a new instance of the SerialPort class using the specified port name, baud rate, and parity bit. |
SerialPort(String, Int32, Parity, Int32)SerialPort(String, Int32, Parity, Int32)SerialPort(String, Int32, Parity, Int32)SerialPort(String, Int32, Parity, Int32) | Initializes a new instance of the SerialPort class using the specified port name, baud rate, parity bit, and data bits. |
SerialPort(String, Int32, Parity, Int32, StopBits)SerialPort(String, Int32, Parity, Int32, StopBits)SerialPort(String, Int32, Parity, Int32, StopBits)SerialPort(String, Int32, Parity, Int32, StopBits) | Initializes a new instance of the SerialPort class using the specified port name, baud rate, parity bit, data bits, and stop bit. |
Fields
InfiniteTimeoutInfiniteTimeoutInfiniteTimeoutInfiniteTimeout | Indicates that no time-out should occur. |
Properties
BaseStreamBaseStreamBaseStreamBaseStream | Gets the underlying Stream object for a SerialPort object. |
BaudRateBaudRateBaudRateBaudRate | Gets or sets the serial baud rate. |
BreakStateBreakStateBreakStateBreakState | Gets or sets the break signal state. |
BytesToReadBytesToReadBytesToReadBytesToRead | Gets the number of bytes of data in the receive buffer. |
BytesToWriteBytesToWriteBytesToWriteBytesToWrite | Gets the number of bytes of data in the send buffer. |
CanRaiseEventsCanRaiseEventsCanRaiseEventsCanRaiseEvents | Gets a value indicating whether the component can raise an event. (Inherited from Component) |
CDHoldingCDHoldingCDHoldingCDHolding | Gets the state of the Carrier Detect line for the port. |
ContainerContainerContainerContainer | Gets the IContainer that contains the Component. (Inherited from Component) |
CtsHoldingCtsHoldingCtsHoldingCtsHolding | Gets the state of the Clear-to-Send line. |
DataBitsDataBitsDataBitsDataBits | Gets or sets the standard length of data bits per byte. |
DesignModeDesignModeDesignModeDesignMode | Gets a value that indicates whether the Component is currently in design mode. (Inherited from Component) |
DiscardNullDiscardNullDiscardNullDiscardNull | Gets or sets a value indicating whether null bytes are ignored when transmitted between the port and the receive buffer. |
DsrHoldingDsrHoldingDsrHoldingDsrHolding | Gets the state of the Data Set Ready (DSR) signal. |
DtrEnableDtrEnableDtrEnableDtrEnable | Gets or sets a value that enables the Data Terminal Ready (DTR) signal during serial communication. |
EncodingEncodingEncodingEncoding | Gets or sets the byte encoding for pre- and post-transmission conversion of text. |
EventsEventsEventsEvents | Gets the list of event handlers that are attached to this Component. (Inherited from Component) |
HandshakeHandshakeHandshakeHandshake | Gets or sets the handshaking protocol for serial port transmission of data using a value from Handshake. |
IsOpenIsOpenIsOpenIsOpen | Gets a value indicating the open or closed status of the SerialPort object. |
NewLineNewLineNewLineNewLine | Gets or sets the value used to interpret the end of a call to the ReadLine() and WriteLine(String) methods. |
ParityParityParityParity | Gets or sets the parity-checking protocol. |
ParityReplaceParityReplaceParityReplaceParityReplace | Gets or sets the byte that replaces invalid bytes in a data stream when a parity error occurs. |
PortNamePortNamePortNamePortName | Gets or sets the port for communications, including but not limited to all available COM ports. |
ReadBufferSizeReadBufferSizeReadBufferSizeReadBufferSize | Gets or sets the size of the SerialPort input buffer. |
ReadTimeoutReadTimeoutReadTimeoutReadTimeout | Gets or sets the number of milliseconds before a time-out occurs when a read operation does not finish. |
ReceivedBytesThresholdReceivedBytesThresholdReceivedBytesThresholdReceivedBytesThreshold | Gets or sets the number of bytes in the internal input buffer before a DataReceived event occurs. |
RtsEnableRtsEnableRtsEnableRtsEnable | Gets or sets a value indicating whether the Request to Send (RTS) signal is enabled during serial communication. |
SiteSiteSiteSite | Gets or sets the ISite of the Component. (Inherited from Component) |
StopBitsStopBitsStopBitsStopBits | Gets or sets the standard number of stopbits per byte. |
WriteBufferSizeWriteBufferSizeWriteBufferSizeWriteBufferSize | Gets or sets the size of the serial port output buffer. |
WriteTimeoutWriteTimeoutWriteTimeoutWriteTimeout | Gets or sets the number of milliseconds before a time-out occurs when a write operation does not finish. |
Methods
Close()Close()Close()Close() | Closes the port connection, sets the IsOpen property to |
CreateObjRef(Type)CreateObjRef(Type)CreateObjRef(Type)CreateObjRef(Type) | Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject) |
DiscardInBuffer()DiscardInBuffer()DiscardInBuffer()DiscardInBuffer() | Discards data from the serial driver's receive buffer. |
DiscardOutBuffer()DiscardOutBuffer()DiscardOutBuffer()DiscardOutBuffer() | Discards data from the serial driver's transmit buffer. |
Dispose()Dispose()Dispose()Dispose() | Releases all resources used by the Component. (Inherited from Component) |
Dispose(Boolean)Dispose(Boolean)Dispose(Boolean)Dispose(Boolean) | Releases the unmanaged resources used by the SerialPort and optionally releases the managed resources. |
Equals(Object)Equals(Object)Equals(Object)Equals(Object) | Determines whether the specified object is equal to the current object. (Inherited from Object) |
GetHashCode()GetHashCode()GetHashCode()GetHashCode() | Serves as the default hash function. (Inherited from Object) |
GetLifetimeService()GetLifetimeService()GetLifetimeService()GetLifetimeService() | Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject) |
GetPortNames()GetPortNames()GetPortNames()GetPortNames() | Gets an array of serial port names for the current computer. |
GetService(Type)GetService(Type)GetService(Type)GetService(Type) | Returns an object that represents a service provided by the Component or by its Container. (Inherited from Component) |
GetType()GetType()GetType()GetType() | Gets the Type of the current instance. (Inherited from Object) |
InitializeLifetimeService()InitializeLifetimeService()InitializeLifetimeService()InitializeLifetimeService() | Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject) |
MemberwiseClone()MemberwiseClone()MemberwiseClone()MemberwiseClone() | Creates a shallow copy of the current Object. (Inherited from Object) |
MemberwiseClone(Boolean)MemberwiseClone(Boolean)MemberwiseClone(Boolean)MemberwiseClone(Boolean) | Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject) |
Open()Open()Open()Open() | Opens a new serial port connection. |
Read(Byte[], Int32, Int32)Read(Byte[], Int32, Int32)Read(Byte[], Int32, Int32)Read(Byte[], Int32, Int32) | Reads a number of bytes from the SerialPort input buffer and writes those bytes into a byte array at the specified offset. |
Read(Char[], Int32, Int32)Read(Char[], Int32, Int32)Read(Char[], Int32, Int32)Read(Char[], Int32, Int32) | Reads a number of characters from the SerialPort input buffer and writes them into an array of characters at a given offset. |
ReadByte()ReadByte()ReadByte()ReadByte() | Synchronously reads one byte from the SerialPort input buffer. |
ReadChar()ReadChar()ReadChar()ReadChar() | Synchronously reads one character from the SerialPort input buffer. |
ReadExisting()ReadExisting()ReadExisting()ReadExisting() | Reads all immediately available bytes, based on the encoding, in both the stream and the input buffer of the SerialPort object. |
ReadLine()ReadLine()ReadLine()ReadLine() | Reads up to the NewLine value in the input buffer. |
ReadTo(String)ReadTo(String)ReadTo(String)ReadTo(String) | Reads a string up to the specified |
ToString()ToString()ToString()ToString() | Returns a String containing the name of the Component, if any. This method should not be overridden. (Inherited from Component) |
Write(Byte[], Int32, Int32)Write(Byte[], Int32, Int32)Write(Byte[], Int32, Int32)Write(Byte[], Int32, Int32) | Writes a specified number of bytes to the serial port using data from a buffer. |
Write(Char[], Int32, Int32)Write(Char[], Int32, Int32)Write(Char[], Int32, Int32)Write(Char[], Int32, Int32) | Writes a specified number of characters to the serial port using data from a buffer. |
Write(String)Write(String)Write(String)Write(String) | Writes the specified string to the serial port. |
WriteLine(String)WriteLine(String)WriteLine(String)WriteLine(String) | Writes the specified string and the NewLine value to the output buffer. |
Events
DataReceivedDataReceivedDataReceivedDataReceived | Indicates that data has been received through a port represented by the SerialPort object. Assumed ItToday, With The Release Of The 2018Version Of This Ultra-powerful Software, Users Can Easily UseAnimation Projects In A Variety Of Ways, Three-dimensionalCharacters And Their Designs. Autodesk motionbuilder 2009 crack. |
DisposedDisposedDisposedDisposed | Occurs when the component is disposed by a call to the Dispose() method. (Inherited from Component) |
ErrorReceivedErrorReceivedErrorReceivedErrorReceived | Indicates that an error has occurred with a port represented by a SerialPort object. |
PinChangedPinChangedPinChangedPinChanged | Indicates that a non-data signal event has occurred on the port represented by the SerialPort object. |
Security
SecurityPermission
for the ability to call unmanaged code. Associated enumeration: UnmanagedCode