Error - The PortName Cannot Be Set While The Port Is Open
Aug 6, 2009
I have this problem says that "the portName cannot be set while the port is open". When this errors occurred, my application on sending sms could not work. Before I edit the application can work but after making some changes and ask help in this forum, the application does not work and gives errors and it says "the portName cannot be set while the port is open".
I was wondering if its possible for VB to display all available COM ports that are open. he reason that I ask this is because this program will be run on various computers where the COM port will not always be the same. I have a text box now that the user can choose which com number he/she wants but if the wrong one is entered, the program crashes rather than displaying an error message. It would also be nice for the system to show which available com numbers there are
I'm making a Visual Basic GUI application to display whether a number of my ports are open for people to know whether things like my website and my Minecraft server are open.My problem is I have absolutely no idea how to do this in Visual Basic.Basically, I'm asking for something which sends a signal to an IP with a specific port, if it is open then return true, if it's closed, return false. Similar to: http:[url]....
I need to transfer data between several computers in a network using my app. I thought of using TCP ports. how to open and use them? I only want to make a file transfer and chat app that works offline.
Public Class my_class Dim WithEvents COMPort As New System.IO.Ports.SerialPort
Public Sub FindReader() Dim ports As String() = IO.Ports.SerialPort.GetPortNames() Dim port As String For Each port In ports
[Code3]...
When it runs, it shows a single COM port "COM1". I am assured that the device attached to it is a standard 8,n,1 and uses 9,600 baud. The exception is "Acess to the port 'COM1' is denied".
I have an application which need to send data to particular system on specific port. But the application gets hang if the target system port is closed.
I Want to know if a particular Port is open on a specific IP address so that i can continue my next task. PBL (Visual Studio 2010 Ultimate)
I have written some code to check if a port is open. I'm currently trying to work with the system.net.sockets name space.I know that the easy way out would be to use AxWinsock, but I don't think the AxWinSock is very cool, nor do I think it's very professional when trying to make network applications in VB.NET.
I've got this Error message : Socket Exception Was unhandled, No connection could be made because the target machine actively refused it 127.0.0.1:1 IDK, Like I said, I'm new to the System.net.sockets namespace, I'm pretty good with other stuff in VB.NET, but when it comes to the serious stuff like the system.net.sockets namespace, I'm not so great.look at this code and tell me what I am doing wrong, I've manged to get this far, and I don't want to just give up and continue watching my movie.
I wrote a program that uses the following class from that site: VB.NET Tutorials - Serial Port Communication In VB.Net. The problem is that I cannot open a virtual serial port, and the second is that I want to make the communication asynchronous.
This is the subroutine which reads from the port: #Region "comPort_DataReceived" ''' <summary> ''' method that will be called when theres data waiting in the buffer ''' </summary> ''' <param name="sender"></param> [Code] .....
In VB6 I had to always check if the port was open or not. But with VB.NET and the new Serial Port control I don't see any.If SerailPort1.Open then statements. In fact when I tried to use the code I got Expression does not produce a value.So does this mean that we no longer have to check to make sure the port closed?Is there a way to check if the port is open or not?
I have a class that inherits from the TcpListener, this class Shadows the Start method just to call the base Start() and the base BeginAccept Tcp Client(). From time to time the method is called but the port is not opened (netstat does not show the port open).[code]The class that uses the ExtendedTcpListener implements the IDisposable pattern and inside the Dispose the ExtendedTcpListener.Stop is called.The stop text is not present at the logs when the problems happens.
I have a few USB devices that use standard Microsoft Virtual COM Port drivers. More specifically, I believe they use the "Usbser.sys" driver. Whenever I plug my USB devices in, they always shows up in the Device Manager as a COM port, however, sometimes I am unable to open that COM port. This problem occurs on both Windows XP SP3 and windows 7 machines (The only operating systems I have tested this on).
To be a little clearer, I can plug my USB device in, and then successfully open the COM port. I unplug my USB device, then plug it back in, and I am unable to open the COM port. The only solution to this problem is to restart my PC. Is there any solution in VB.net to reset any entrees made to the Windows system when the USB device is plugged in? Has anyone come across this problem and resolved it via a VB.Net solution?
I have a programme that accepts data from a serial port. If I close the port and then the form no problem. However if I try to close the form with out closing the port it appears to hang. I have tried closing the port in the forms close event but this did not solve the problem.The data recieved event is as below and UseData is the private sub which actually handles the data. Usedata contains the code line Dim InputText As String = SerialPort1.ReadLine Private Sub SerialPort1_DataReceived(ByVal sender As System.Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
Me.Invoke(New myDelegate(AddressOf UseData), New Object() {})
End SubI am aware that this event runs on another thread and I have seen but cannot now find information about closing multiple active threads.or do I have to "uninvoke" the delegate
I tried to make a winsock program.But when i run, i have a SocketException "No connection could be made because the target machine actively refuse it."Any suggestions on what i should do? Im using 17477 port.By the way Im using my own computer to test it. So i have no idea why.How should I open this specific port in my own computer?
Is it possible that I could include it to could into my program so that i don't need to open the ports of each computer? Below is my code.
I'm having this problem with a networked app in vb.net. If the program exits normally the port closes fine, however, if it crashes sometimes it remains open and I am unable to close it. The next time I run the program it is unable to open the port because it is already in use. Here's the exception: 10048: Only one usage of each socket address (protocol/network address/port) is normally permitted on how I can reclaim this port, or how I can close it? I tried using the reuse address socket option
I have things set up so that the program is ready to start logging ,only when Recieving=true.This is controlled with Button1. So I click button1,Serial port is open and waiting for some signals from the Dyno.When 1 signal come it put a "1" in TextBox1 ,and for the second a "2" and so on. Thing is sometimes it starts right away, like I want it to,and sometimes it lags a fraction of a second, even though the Port is open.When it lags there are already 5 to 10 signals gone by before it starts logging 1,2,3,...and so on. Sometimes it don't start at all.Then I have to close and re-open the form and it works,but with lagging on the first "set"
"Textbox1 > 0 then" triggers a timer (not seen in this code)that samples Textbox1 once pre interval and writes the value to a listbox. On the upside as soon as a "1" is displayed in textbox1 the timer starts like it's supposed to.I noticed this behaviour before I added the timer and besides the timer has nothing to do with the signals coming from the SerialPort. I have my form setup so I can run "sets".Run one "set"...save...reset...run another "set" ...and compare.It's always the first "set" thats off.If I run multiple "sets" the first one is completely "whacked", and the rest are consistent.
Think this could be the SerialPort lagging,or code problems?
Public Class Form1
Dim resetValues As Boolean = False Dim RPM As Double
I am currently working on a program that gets data from an external device (microcontroller) and saves the data into a database. I got everything to work except for one simple part. Everytime I disconnect from the serial port, the program stops working and highlights this part of my program:
x = SerialPort.ReadTo("a")
This part just gets the data from the serial port and saves it to variable [COLOR="rgb(72, 209, 204)"]x[/color]This is the complete subclass of my program:
[code]...
It is supposed to read data from the serial port and execute a command that tells VB store the data collected. Whenever I use the function
[COLOR="rgb(72, 209, 204)"]SerialPort.Close()[/color] , the program stops working. What could I be doing wrong? Could the program be stuck in the serialPort.ReadTo() function? Although it does execute the lines in the subclass.
I'm writing an application that imports and tidy up address data into a cleaned, deduped excel workbook ordered in rows with each column as an address field. One of the issues I've ran into is that we sometimes get a workbook where the multiple address fields are held in a single cell with line breaks. I've written code to extract all of this data out of the excel sheet in to a dataset with each sheet as a table and the address fields contained within. I now want to create a new Excel workbook from this data with the address fields in Row and columns the problem I have is I can Open/create the Workbook but when I try to insert a new Sheet (Table) I get an error saying the Workbook is read only....
Private Sub MakeSimpleXL(ByRef DsTemp As DataSet) Dim dsTable As Data.DataTable Dim tblName As String Dim dsRow As Data.DataRow
[CODE]...
Here is the error: System.Data.Odbc.OdbcException: ERROR [42000] [Microsoft][ODBC Excel Driver] Cannot modify the design of table '3 _ 10$'. It is in a read-only database. at System.Data.Odbc.OdbcConnection.HandleError(OdbcHandle hrHandle, RetCode retcode) at System.Data.Odbc.OdbcCommand.ExecuteReaderObject(CommandBehavior behavior, String
[CODE]...
It looks to me like it is trying to create the table (Sheet) but has the workbook opened as read only....
I did a search for "How do I implement Serial COM Port communications? and found a response by Xiaoyun Li which was last posted on April 10, 2009. Xiaoyun's response included sample code. My intent has been to get a clean compile on the sample code, then test it, then expand the code into a real application. I am down to a single error message, which I can't figure out how to resolve: "Method 'Public Sub DoUpdate()' does not have a signature compatible with delegate 'Delegate Sub EventHandler(sender As Object, e As System.EventArgs)'." [code]I marked where the error occurs in the code with *** to the right of the error line.The code is attached to a simple form, Form1 which contains a single text box, TextBox1.It appears to me that the code needs a Delegate statement, but I can't figure out how to code it or where to put it.d.
I'm working on a type of p2p program, and I found the need to forward ports. That can get complicated for the average user, so I'm including the option to use UPNP to forward the ports for them. I'm using code I found HERE, and it worked too! then randomly it stopped working. I don't remember changing anything in the codeThis is the entire code. I have the Exception Highlighted in Red. The project includes a Listview (6 columns), three buttons (4, 5, 6), a progress bar, and a background worker.
Imports System.Net.Sockets Public Class Form1 Dim upnpnat As New NATUPNPLib.UPnPNATClass()
I'm trying to make a rs232 serial data logging program, that accepts a 12 bit hex RFID tagID from an RFID module. My end objective is to save this RFID tagID into a database and assigned to a person for a personnel management system.I had to use button3 to add the value of the variable 'msg' into textbox1 because I was getting the following error "Cross-thread operation not valid: Control 'TextBox1' accessed from a thread other than the thread it was created on". It is a temporary workaround.When I do press button3, I get the incomplete hex number, instead of "4C00A2C82A0C", I get "A2C82A0C", and sometimes I get random digits like 1,A,C etc etc.
Public Sub OpenPort() Try If SerialPort1.IsOpen Then SerialPort1.Close()
