Serial Port with portable data terminal

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In this simple article you will learn that how you can Open and read COM port data using System.IO.Ports Namespace.
Simply just create New Project of windows application in C#.

Import ServiceProcess APIs
C#:
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using System.IO.Ports

VB
Imports System.IO.Ports

Write Parsing functions which parse port data according to attached device

Hi Is it to possible to wait for a serialPort component to complete it's response?  I have a device connected to the serial port of my PC. I use the serialPort component in order to communicate with the device. I have to send 2 different strings of data to the serial port but the trick is that after sending the first string of data I have to wait for the serial port to respond. Then I have to check the response and decide whether I must send the second string or not. Also after sending the second string, I have to check also the response of the serial port. I tried to use an arbitrary amount of wait time between the sending of the two strings. Something like SerialPort.Write(...) ; Thread.Sleep(2000); SerialPort.Write(...); But the software failed when I tried it in a slower PC. So is there a way to replace the Thread.Sleep(2000) with a command that will wait until the serial port complete its response? Although, the response of the serial port is different between the two sending strings, I do know that the first response is only one byte and I know the ending byte of the second response. Also, the second response is no more than 30 bytes in length. Regards Dimitris

I am developing an application which sends multiple AT commands to a modem in VB.Net. After writing an AT command to the modem, I see the dataReceived event is not getting triggered until I close the port & open it again & write the next AT command. This behavior is consistent. As soon as I write the next AT command the response of previous AT command is read. Even adding a delay between the two write operations does not work. I also added a readData between the two writes so that data is read if it exist in buffer or stream but is not triggering datareceived event because bytestoread is non-zero, but that does not hep too. Because of insufficient read operations the data in readbuffer grows(accumulating) & after sometime the modem stops receiving the AT commands. Please suggest a solution code for data received handler & read data function   While comPort.BytesToRead > 0     Dim msgCharArray(255) As Char       If comPort.BytesToRead >= 256 Then     comPort.Read(msgCharArray, 0, 256)   Else    comPort.Read(msgCharArray, 0, comPort.BytesToRead)   End If   End While

Hi.... I have an issue related to serial port opening. when i run my software it gives me an error "serial port does not exit or already opened". I have two questions. 1.can i check which program is using com port. And how can i close serial port that is already being used.Using Windows7  

Sometimes it happens that opening one file or serial port fails because it is used by another process.

Is there a way to get the name of the process that is using it ? 

Thank you

Is there a way to register a callback or delegate that gets invoked by the system every time a new virtual COM port is connected to a USB interface ?

This function would be very useful to keep serial port enumeration up to date without polling.

Thank you

The application (C# .Net 3.5) available at www.redondowa.com/porttest demonstrates a problem encountered with a Sony VAIO multimedia laptop related to use of its serial modem port.  A discussion with MS support is included in a doc with the VS solution.

If the base stream or port is not closed before nulling the port, the port cannot be recreated and the application leaves the port inaccessible.  The machine requires a reboot to clear the error.  Other machines clear the error without requiring a reboot.

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Hi,

I need to dump a huge number of characters per second to a PC from a simple micro controlled device rs232 port at the least for debugging purposes.

I can select and sucesfully transmit/receive at speeds up to 3M baud without significant data coruption on short packets, however for sustained data I get too many overrun errors for it to be usefull, even at 230K buad it is too much.

I am using a usb serial cable, on windows 7 (64) on an I7 system, so it should have plenty of cpu power to keep up. it only needs to service it twice per millisecond at 230kBaud to keep up.

I am programming with C# and have 3 threads, one for the UI, one for the port, and one for decoding the data.

I have a large data buffer, and I am calling read fast enough so that I get about 100 characters on average, the SerialPort object port buffer is set to "very big" (64k), with byte threshold set to 100, setting it to 1 makes no difference.

The 16 byte Fifo on the usb serial cable is set to 1, but this makes little diference.

From what I have read it is the device driver not reading the usb port fast enough, and the usb serial cable "chip" runs out of buffer.

I have tried different usb serial cables, but they have the same 16 byte buffer and the same problem.

Is there any way I can speed this up ? I would of th