Change The .BaudRate Property Of A System.IO.Ports.SerialPort While It's Already Connected?
Nov 18, 2010
For whatever odd reason, we have a legacy data recorder device that runs at 9600 baud. Except when it needs to transfer its recorded data to a PC, in which case it switches to 57600 baud.
The old VB6 code worked, although it had its own set of problems of course.
The routine is this: Do several COMMAND/RESPONSE routines to populate a list of available records, listed by timestamp, at 9600 baud. Once a timestamp or several are selected, display a file save dialog. At the moment that dialog is closed, send a command to the device to tell it "hey we're going to warp", sleep for 100ms, then set the baud rate property of the persistent COM1 connection to 57600, before beginning to process XMODEM data and do the progress bar dance.
The problem I'm having is that it doesn't appear that the data received is ever really kosher as far as the byte marshaling is concerned. Which makes me wonder just how well SerialPort is at dynamically changing bauds on the fly. The VB6 version used MSComm.
I've even attempted to just use MSComm through the compatibility layer but "CTL_E is not supported" which makes it sound like it's incapable of doing XMODEM. (?)
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Jun 3, 2010
How can I make multiple instances of System.IO.Ports.SerialPort and declare them on the fly? I need to monitor multiple RS232 ports based on the EU's selection. EU will select ports e.g. 1,2,6,9,11 and rename them as necessary. Selections will then be stored in a settings file.I would like to declare these at runtime e.g
Com1 is renamed LabelPrinter
Dim comLabelPrinter As New System.IO.Ports.SerialPort
With comLabelPrinter
[code]....
Or if not, make multiple instances based on the number of ports selected and renamed.The declaration based on the rename would just make it easier to work with but can be committed?
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Jan 24, 2012
I'm having a bit of trouble with the SerialPort class I'm hoping someone might be able to shed some light on. Specifically, writing to the port appears to work without incident. However, reading data is proving problematic. Initially I thought it was my hardware, but testing suggested the fault lied in software. I was able to confirm this with the installation of a loopback device on the port. It tends to be missing bytes, inserting bad bytes, and shifting bytes randomly.
[Code]...
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Mar 16, 2009
I want to send some data through a serialport (USB) permanently and got a problem once the USB interface crashes. Sometimes it just happens, but if I ask the PC "serialport2.isopen ()" I will get a TRUE, even though the USB cable was uplugged. How can I check if a connection is still available. CDHolding wasnt working either. I am using VB 2008 Express
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Nov 12, 2009
In my project I'm trying to get the caption property of serial ports available on computer. But when I run this code below I get "A first chance exception of type 'System.InvalidCastException' occurred in Microsoft.VisualBasic.dll" exception. I tried putting "Option Strict On" and then I'm getting build error saying it disallows Late binding.
[Code]...
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Aug 13, 2010
I am writing a small app that is retrieving data from a device connected to a virtual com-port. I connect without problems to the device using the settings 9600-8-N-1.
I need to send the command <esc>MS , the device then sends back the data to a computer. I have tried this using Hyperterminal with success. I also did this with Excel and VBA. I used the MSComm32 Active X control:
MSComm1.Output = Chr$(27) + "M" + "S" + Chr$(13)
Msgbox(MSComm1.Input)
This made the data from the device pop up in a messagebox. I am writing a winforms app in vb.net, using VS2005. I have a form, on which I have a Placed a SerialPort control, named sp. My sample code is as follows:
Private Sub Form1_Load(ByVal
sender As System.Object,
ByVal e
[CODE]...
This returns the error message "Error: expecting a command". I have done som tests in HyperTerminal, and have concluded with:
-If I dont send <esc>, I get error "Expecting a command"
-If I send wrong command (ie MD instead of MS) i get error "Bad command"
Based on this, I suspect that I don't pass the escape character correctly to my device. So I wonder how to do this?
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Feb 19, 2011
There is a problem in my project. It has a class with several properties. When I set the property, it send command to device through serialport. But the problem is when I get the property, it need to send request command to device, and device return value back. How can I update the property?
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Nov 30, 2010
Can someone please help me create a very very simplistic sample page as the chat page included is too coomplete. something as simple as detecting a change in the database and displaying the word "change" on screen in realtime for any client connected.and I tried creating a global.asax file into which I added in the line mentioned in the link above, but it does not seem to like the word "Setup" in the line [code]
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Jan 16, 2009
i think there are errors in the SerialPort DataReceived Handler in .Net 3.5 and .Net 3.5 SP1. is there a way i can control which version of System.IO.Ports my application uses? i am using VB 2008 Express.
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Dec 17, 2010
I want to know if there is a way to refresh a combo box when a new serial port becomes available.[code]
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Jan 31, 2012
I'm trying to make a simple Class that reads data from a SerialPort.The Device returns a number of lines of Strings.
Code:Public Class Device
Private Device As New IO.Ports.SerialPort("COM4", 4800) Private WithEvents tmr As New Timer Public Event GotData(ByVal Data As String)
[code].....
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Jul 22, 2009
I'm wondering how I could monitor a serial port for a voltage change or contact closure and have an event triggered when there is a detection.
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Mar 10, 2010
I inherits textbox Control and I added some new properties to it .one of these properties value i want it to change it's value in desgin time when i change Name property of the new textbox
Public Class NewTextBox
Inherits TextBox
Private _txtSubName As String = String.Empty
That is the property for set or get SubstringName of Textbox
Public Property SubName() As String
Get
Return _txtSubName[code].....
that's the property i want to change it's value when i change Name property of the control.i tried to overrides Name property but it's not overridable also i trieds to overloads it but it doesn't work in desgin time.Here is something i tried but it's wronge.
Private _txtName As String = ""
Public Overloads Property Name() As String
Get[code]......
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Nov 24, 2010
I am writing a serial application using VB .net Framework V4 , where I use a background worker to Read a file and send it to a serial port using SerialPort1.writeLine method. The BackgroundWorker1.ProgressChanged Event handler sub Updates the Line Number to a TextLabel and adds each line sent to a RichTextBox using RichTextBox1.AppendText() method on main form (Form1).
The problem arises at 115200 Bauds (and higher),may be because now the text is updated real fast on the form an unhandled Exception in BackgroundWorker1.ProgressChanged Event handler sub occurs. Otherwise at lower baudrates ex: 9600,19200 etc. Application Runs Perfectly Fine.
[Code]...
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Nov 15, 2010
I am working on a client system . How i will get IPAddress of all the system connected through lan.
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Nov 13, 2011
I want to be able to change my network on the press of a button to another favorite network followed by the launch of a LAN based game and closing a set of pre-defined internet applications that will interrupt gameplay with "Lost connection" popups Basically I have two networks, on Internet, one only LAN (Both Wireless)I want to be able to switch networks and launch my game. I know the code for launching my game, but my question is....How do I switch network connections using my program?
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Jun 18, 2010
What I'm looking to do is 'hook' a physical drive connected to the system so I can process data coming through the API before it's written to the disk. I have a sense DeviceIOControl is where I should be, but I can't seem to find any IOCTL code that uses a callback (which is what I expect I should be using to scan/process data on its way through the API).
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Nov 7, 2011
I am designing a Point Of Sale system to be used by sales representatives. The sales rep should be able to place an order of a specific product on behalf of the customer. I have defined my relationships between the tables, Product, Order and Customer. When i try to save my orders i get an error that says "you cannot add or change a record becuase a rerlated record is required in table Product"
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Feb 4, 2012
I have a thesis project. it is composed of a webpage created on php and a system using vb.net 2008. As of now , they are both connected to the same database. I am wondering if it is possible that if i packaged the system and live the website, will still be connected with one database?
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Jul 2, 2009
I have a connection to an access database, I have used the data sources tool provided because in this particular instance I don't want to do much with it other than display the records (which I can do) and edit them (which I'm haveing some trouble with).I have created a system whereby the database is connected to using the preset tools available like; BindingSource, TableAdapter, BindingNavigator etc.
I also have a button for edit. This doesn't work and I was wondering if anyone could help me with this? I can't really provide any code for this, because I didn't code the connection by hand and the code I have been attempting to use for editting the records in the database doesn't even sort of work.
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Apr 4, 2012
Here is the stack trace:
2012-03-16 19:15:09Z E System.NullReferenceException: Object reference not set to an instance of an object.
at System.Timers.Timer.set_Enabled(Boolean value)
at System.Timers.Timer.Stop()
Here's the code:
Timer declared as private member variable.
Private _myTimer As System.Timers.Timer
Initialize timer method.
[code]....
The timer has to have a value or else the Timer.Stop() call would be throwing the exception. This is a sporadic error and I'm just trying to see if anyone has experienced this before or if anyone has any ideas of what could be causing it. It is occuring in a WinForms application in the event handler for the Elapsed event of the Timer, but it is only occuring sporadically on the users computer. I haven't been able to reproduce the error myself.
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Apr 4, 2011
On my program I am trying to make a ToolStripStatusLabel's text change to "connected" if connected to a network and if not connected to a network change the text to " Not Connected" then I don't know how to display a image if connected to a network or not connected. So if the computer is connected to a network I have a image that I would like to be displayed next to the ToolStripStatusLabel. And if not connected to a network, can the program display a different image? I tried this:
My.Computer.Network.IsAvailable=True(ToolStripStatusLabel2.Text "Connected")
My.Computer.Network.IsAvailable=False(ToolStripStatusLabel2.Text "Not Connected")
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Nov 10, 2009
I am trying to find out if the connection of my sockets (TCPClient) is connected or not connected. I am using the following code:
[Code]...
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Jan 13, 2010
I'm working on a simple base form in which all the other forms in the project will inherit. This base form only adds 5 properties (at the moment) dealing with painting a gradient background. The problem I'm facing right now is when I change a property on Form1 (the test form) and click run it doesn't show that change. I also checked the .designer.vb file and when I make a change it's not added to the code behind file, I'm at a loss right now to why.
[Code]...
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Apr 28, 2009
I have been working with System.reflection namespace and i have problems to get value of properties in system.__ComObjectMy objective is:obtain a collectionfor each object in collection get the propertie (example ID)
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Oct 31, 2011
I am not sure what I am supposed to write in the code behind for my vb.net project. I have a repeater that filters a gridview. When trying to declare the scalar variable @CompanyID, I get the error.
dsLetters.SelectCommand = "SELECT DISTINCT LEFT(ProductName, 1) AS [Letter]
FROM Product, CompanyLink, Company
WHERE Product.ProductID = CompanyLink.ProductID
[code]....
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Jan 25, 2010
I am a newbie at ASP.net and after using sqldatasource with a listview to insert and show results from an SQL server db I want to try using the LINQ datasource since it seems to be more flexible in codebehind.
My problem is this: I droped a listview control to the page and I created the Linq datasource in codebehind with vb. the issue that I am having when I ..Select d.columms name i get the error system.string does not contain a property with the name "columname".. if i ommit the column name then its works fine.. the funny part is the d.count works fine but after that i get the error.. please see my code below:
[Code]...
b.dbMake needs to work so that i can use Distinct ,, ia m using asp.net version:3.5 and IIS version 7.0 ..
not sure what i am missing ,, but i did try alot of approaches,,1- checked the web.config file and it seems to have two assemblies and two namespaces for LINQ..2- used different databinding syntaxs,,and i searched a lot for the solution.. the last one i read the person ommited the name of the column,, i thought that wasnt the best solution.. also my dbMake column is comming up in the "intellisence"
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Oct 2, 2011
I want to click on the button, then change the itself position
the visual studio prompt me that is a public property, and the type is double. Why I cannot change the value? And it does not provide any method let me change the top property, so how I can change the property?
<Button Content="Button" Grid.Column="1" Height="23" HorizontalAlignment="Left" Margin="0,0,0,0" Name="Button1" VerticalAlignment="Top" Width="75" Grid.Row="1" />
MsgBox(Button1.Margin.Top)
Button1.Margin.Top = 10
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May 19, 2012
I have a qeustion where i made a function that changes the property value of an object. the objects + alias are stored in an array (Objects()) , if the var (NewValue) has a value then it checks the property type and converts the Newvalue and inputs it.
[Code]...
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Sep 15, 2011
Want to change a property of a user in Active Directory programatically. I know I need to use DirectoryServices but I keep getting referral errors.
1. I want to connect to the directory an get the property first.
2. I will then use a evaluative expression to find out if step 3 is necessary 3. Want to change ths property
However, I want to run this from client machines so they won't have permission to modify the schema so I created a new users, is it possible to authenticate with one user and change another's?
Tutorials don't seem to show specification of the user the are changing the context user.
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