Update Combobox When Available Serial Ports Change
Dec 17, 2010I want to know if there is a way to refresh a combo box when a new serial port becomes available.[code]
View 2 RepliesI want to know if there is a way to refresh a combo box when a new serial port becomes available.[code]
View 2 RepliesI'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.
View 1 RepliesWhat is the best way of communicating with Serial ports and TCP/IP communcation using vb.net?Using visual studio .net can we make it easier?? Can anyone send me sample application of communications?If I write a program communicating with my hardware using Searial port or TCP/IP, will the program be slow?? Are there any programming techniques working with communication ports?
View 1 Repliesis there any other way to access a serial port using visual basic.net 2010? i followed the steps in this site, How to access serial and parallel ports by using Visual Basic .NET but i just got this output Open the serial port. Send the attention command to the modem. Wait for data to come back to the serial port...
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I'm fairly new to Visual Basic (VB), but I've already got running code to access all my serial port. The problem is I want to load multiple serial ports into an array and loop through them in my functions. The program allows me to create ports(), but fails when I try to populate it.
Dim ports As IO.Ports.SerialPorts()
ports(0) = SerialPort1
Where SerialPort1 is an object I draged from the Visual Studio toolbox.
I'm learning the serial port programming. So, I study the code samples from MSDN - VB101SamplesBCL2 http:[url].....While ran the solution of "UsingTheSerialPort", It shows error: It highlights one sentence textBox2.Text = SerialPort1.ReadLine() -- Line 40 ,and says :
"InvalidOperationException was unhandled - Cross-thread operation not valid: Control 'textBox2' accessed from a thread other than the thread it was created on."
able to open and utilize a single serial port within with my VB 2008 program (i.e., set port parameters, open&close port, send&receive data via port, etc.), but I want to open two or more serial ports concurrently within my VB 2008 program so that I can read data from one port, say COM1, make decisions and calculations based on that data, and send instructions out through another port, say COM2.
View 1 RepliesI am still new in programming. I am an electrical engineer. I have to read the time from GPS from one serial port apend this time to a data got from other device serially.
View 1 RepliesI am creating an application to configure some modems through the serial port. I have no problem sending a single string of data to the serial port and displaying the immediate response to a rich text box. I have 2 problems
1st: how to update the rich text box for any delayed response from the modem
2nd: how to react to the response from the modem, in other words I want to send the next command based on the response from the modem witch is usually "OK"
This is what my code looks like currently to send ans receive data from the serial port. (sport1 is my serial port and display is my rich text box)
sPort1.Write("AT+WOPEN=1" + Environment.NewLine)
With Display
.AppendText(sPort1.ReadExisting())
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I'm reasonably proficient with VB but never had any expirence with communicating with hardware. I have a piece of software that communicates with a Eurotherm 3216 process controller via RS232, but its use is fairly restricted what it can do.What I want to be able to do is take the communication from the software and redistribute it to THREE Eurotherm 3216 controllers, so my software would intercept the comms and effectively emulate the Eurotherm.
View 5 RepliesI have the following code to create an array of serial ports.
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title is a bit vague. Is there any way I can tell if it's the user or the code that's altered a combobox? I want certain things to happen when a combobox is updated, but I don't want them to happen when the code is altering the combobox at runtime, only when the user selects something out of them. Unfortunately, if I use the 'Selectedindexchanged' option that triggers when I change the contents in code too. I've tried disabled the combobox while I update it, but that doesn't seem to work. Any way to detect user input only? My combobox is drop-down only by the way, so it's only if they select an option - they can't type anything.
View 10 Replieswhat is wrong with my code and I get no feedback from my button click event, i have imported. ( code Below) and i have tied differrent combinations of the code without sucess.maybe add extra to my code for the list to show open Port or closed ports.
Imports System.Management
Imports System.Management.ManagementObjectSearcher
Imports System.Management.ManagementNamedValueCollection[code].....
I am using the following code to enumerate through com ports to determine if the attached modems are in use.When I get to my usb modem, it returns the correct "PostIsAvailable" status, but then it kind of locks up the modem and I get the following error when I try to manually query the modem I get: "The modem failed to respond. Make sure it is properly connected and turned on. If it is an internal modem, or is connected, verify that the interupt for the port is properly set."I either have to manually requery the modem or unplug/plug it again.This code works fine on my external serial modem, but not the USB modem.
Public Function PortIsAvailable(ByVal port As String) As Boolean
Dim TempPort As New SerialPort
TempPort.PortName = port [code]......
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.
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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. (?)
i am using the below code in VB.Net to load the available serial ports :
COMsComboBox.Items.Clear()
Dim i As Integer
For i = 1 To My.Computer.Ports.SerialPortNames.Count
COMsComboBox.Items.Add(My.Computer.Ports.SerialPor tNames(i - 1))
Next
i also want to load their names as seen in the "device manager",
Is there a way to update source combobox to printer combobox selection?So going from printer1 to printer2 the source will update according to what that printer has to offer.
View 8 Repliesi want to update the serialnumber by using a text box,,,,suppose i am updating the serial number as 3,,,,it was updated,but if i wants to update the serial number as 4 ,that is already in the database it is also updated..but actually it is not updated..but it is updated.........
Protected Sub Button3_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button3.Click
Try
Dim conn As New SqlConnection(ConfigurationManager.ConnectionStrings("guest1").ConnectionString())
Dim adp As SqlDataAdapter
[code]...
I am new to vb.net and I am using visual studio 2010. I have two comboboxes on a form, each combobox is set to DropDownList so that a list of items can show in the combobox, but no text is allowed to be entered.
For combobox A, if user chooses item 1, the list of combobox B should be updated accordingly. I think this is quite common on a lot of applications. But I do not know to implement it. I even do not know the keyword to search for the relevant property or event handler.
I`m trying to write a small program which connects to a serial port at 115kbps and reads a stream of continuous bytes from a microcontroller. The program should then graph these bytes by time. Ideally this all happens in "real time" and as quickly as they can be sent.With a 50ms serial write delay on the micro the VB program keeps up fine, but if I lower the delay any further, say down to 1ms, the update can`t keep up and the serial buffer just grows.I wasn`t expecting the bottleneck to be the PC side so it`s likely my code is doing something wasteful. Or maybe it`s the graphics which are drawing slow?
Private Sub DrawGraph()
Try
Dim y As Integer = m_Y
Do
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I have a gridview in which when I click edit, update, and cancel button comes. I have a variable named status. If status=false then update should change to insert and if status=true then update should be update itself.
<asp:TemplateField >
<ItemTemplate>
<asp:LinkButton ID="lnkEdit" runat="server" CommandName="Edit" Text="Edit">
</asp:LinkButton>
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I have two combobox in a form: Cb1 and Cb2
When I load the form, Cb1 and Cb2 are connected to a bindingsource.
When I change Cb1, the code (below) changes Cb2 to show only the items according to Cb1
This is working fine.
The problem is when I change Cb1 , change Cb2 and click the save button..... Cb2 seems to be 'lost'...
I'm using VS2008.
CODE:
I have a DGV I am working on, and I have many columns.
For example I have Columns colcase(Combobox), colreportTime(Time)
the combox shows 4 cases {A,B,C,D}
what I need to do is if the user select "C"
the the colreporttime will show the time of this change unless the old value is C
I have two comboBoxes, one is CountryCombo and second is StateCombo.What I want is the that when i the clicks country combo and select a one country then the States of that the country should get populated in the State Combo.I have tried things many many many but nothing working. Below is my code of how my CountryCombo is getting filled.
query="select CountryName from CountryMaster"
if dr.hasRows()
{[code]......
Why is it sometimes when I update a data using da.update(ds), the data sometimes didn't update or change... for example i want to change the name or number n a record, sometimes there is no changes..
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I made serial COM1 work by default settings in serial port properties. If I want to change to another port,e.g. COM2 as well as change other settings (baud rate, data its, etc.), how to re-open this new port?
View 2 Repliesim currently working on a program which prints serial text to an aplication like note pad. the problem im having is that i cant figure out how to change which serial comport is being used in code. i want the user to chose the comport with a check box.keep in mind that COM1 in my code is what i called my check box. here is my curent code:
Public Class Form1
Private Sub OpenFileDialog1_FileOk(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles OpenFileDialog1.FileOk
Shell(OpenFileDialog1.FileName, 1)
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I fill my combobox cbx from an Access database as follows:
Public daOfficers As New OleDbDataAdapter, dsOfficers A New DataSet, dtOfficers As New DataTable
daOfficers.SelectCommand = New OleDbCommand("SELECT pID, [pName] & "", "" & [pPrename]
[code].....
I have inherited an application that uses telerik controls. This is my first time to work with it and I'm a little confused.I have a RadComboBox that has its values hard coded. When the user selects an item, a RadGrid is refreshed to show the records that correlate with the item the user selects from this combo box. This all works great.I'm trying to create link buttons, so that when the user clicks on one, the RadComboBox value is changed to whatever value I set it to in the codebeind page and the RadGrid is refreshed to show the appropriate records.I can set the value of the RadComboBox, and see what value it has when debugging, but the RadComboBox in the browser does not reflect the change and the RadGrid is not refreshed when I programatically execute the event handler for it.
View 1 Replies