VS 2010 Caching Real-time Data To Avoid Crashing Chart?
May 10, 2011
- I'm working on a windows forms application (.NET 4.0). - My form contains a 'Fast Line' chart using the Microsoft chart control included in VS2010. - The chart gets filled with about 20,000 datapoints. - My application then starts receiving market data from a server via DDE (Dynamic Data Exchange) in real-time and adds it the chart.
Note: I have no control over the server and so I have to deal with DDE only even though it's an outdated technology. VS doesn't support DDE anymore and so I use the Ndde library which works like a charm.
Private Sub StartDDE()
'first we connect to the DDE server:
Dim client As DdeClient = New DdeClient("ServerApplication", "Bid")
[Code].....
View 1 Replies
ADVERTISEMENT
Feb 22, 2011
Make real time chart?
View 1 Replies
Feb 13, 2012
On VB.NET 2005 and 2008, if you were debugging you could roll over the variable you set as an array and a little "+" would pop up next to the array variable and you could click it and see all of the data loaded into the array.
View 3 Replies
May 24, 2010
connected to my Arduino. Using the VB.NET (2010) GUI I request which LED I want on (via buttons) and the I2C device then sends a reply confirming which LED actually turned on (basic feedback). Ok, sounds great right? Here's where I get issues. Well when I try to read the serial data sent to VB and display the real-time stream on the GUI, a) I get a bit of a mess as an output (values are ok, just spewn across GUI) and b) when I select a new LED to turn on, the GUI data does not refresh to this change. The stream being sent from the Arduino is ok, I looked at the data in a serial monitor.
Public Class Form1
Dim ticktock As Integer
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
[code].....
View 4 Replies
Jan 14, 2009
I'm working on a windows forms application (.NET 4.0).My form contains a 'Fast Line' chart using the Microsoft chart control included in VS2010.The chart gets filled with about 20,000 datapoints.My application then starts receiving market data from a server via DDE (Dynamic Data Exchange) in real-time and adds it the chart.
View 5 Replies
Sep 19, 2010
I have to send a sequence of video frames over UDP as fast and real-time as possible and while I got the basics working, I am running into all sorts of difficulties. Some of my goals:Data will normally be sent over dial-up (hence UDP instead of TCP), but also needs to support fast Ethernet.It's OK to occasionally drop frames (hence UDP instead of TCP).Need low latency. The frame the remote receives should be one that was recently sent (no more than a few frames waiting in buffers).I need to be able to detect the effective bandwidth so that I can compress the frames more or less to keep frame rate up.I break up frame data into one or more datagrams of about 500 bytes and each has a sequence number and other info. The receiver reassembles the entire frame and detects if any datagrams are missing.If the receiver detects more than a certain percentage of dropped frames (e.g. 50% over the last 10 frames), I send a TCP message to the sender to slow down by 50%. Sender than slowly increases speed by 5% each subsequent frame.Using System.Net.Sockets.UdpClient to send and receive the data.I have a separate TCP channel used for control messages back to sender.My main difficulty right now is detecting the effective bandwidth and dealing with latency, especially over dial-up (max ~4,000 bytes/sec). For example, if I try to send 100,000 bytes/second using TcpClient.Send() they ALL seem to arrive (no dropped datagrams) but with large latency by the time last datagram arrives. I think the TcpClient.Send() function is blocking until the buffer is able to send which messes up my current algorithm.
Can anybody point me to any sources of information for how to:Detect actual bandwidth over UDP.A better algorithm for dynamically adjusting bandwidth to suit the available pipe.Send data smoothly at the desired bandwidth.A way to detect and keep latency down to a minimum.I have been spinning my wheels over the last week and every time I solve one problem it seems another rears up is head.
View 1 Replies
Jan 11, 2012
are there any ways that i can extract my data from database and display it into my listbox in real-time? which means that whatever is updated in my database must immediately be inserted into the listbox without the need of refreshing or pressing any buttons. Immediate display.
View 3 Replies
Jun 24, 2012
methods/procedures for sending real time data from a VB.net app to a web server (asp.net) for real time display. My question relates to the best method to send the data from the desktop app and the best way to receive and handle the data on the server. I'm not asking for sample code, just some idea of what methods to research. I am currently using a text file upload method but I'm sure there is a more efficient way of achieving this.
View 2 Replies
May 25, 2012
I have been trying to find and/or think up a way for data to automatically update a data table.I have a log that shows all the customers that came in today with various information. There could be twenty or thirty employees adding to this log or updating or doing things with that customer. This information is in a Data Table on a ASPX page in Visual Studio 2010 that the code is binded in the aspx.vb page that is calling a page in my APP_CODE database file that calls a query in my Database to get the information.My question is could someones actions on a different computer make my computer refresh or to re-bind that data.I have thought of some kind of timer/counter maybe that looks to see if the count of the log is different.
View 2 Replies
Mar 9, 2012
I'm using EF version 4.1, and would like to have the data from the database in realtime, i.e. if you open the application it detects if there is new data in the database, and update the above it! is It possible to do this? I am using EF 4.1 code first time
View 1 Replies
Jun 5, 2012
i have a program that function as a DAQ System.i have input channel to gather information from sensors. The reading of each sensor such as voltage, current and temperature are displayed in the textbook. As we all know, DAQ system is involve taking data real-time measurement.My problem is:
1. how to update each row automatically as time goes on. the value in the textbook is updated by each second.Below figure shows how the excel can be written automatically row by row, as time ticking for a sec. this update will stop as the timer stop.
View 12 Replies
Sep 29, 2011
I have a driver for the device and I already have it integrated into an application.
It is a Human Input Device with buttons.
Controlling the device is not the issue nor is receiving button presses.
I want to retrieve the actual data that is being sent from the device to the computer and from the computer to the device.
I have seen a lot of hardware approaches but not any software approaches(that work right).
View 3 Replies
May 25, 2010
Basically I have a program that receives real time data from microcontroller and displays it in a text box. What I would now like to do is to store the values received into a table that can be viewed when the receive program finishes. However I still want the values displayed as they are received in addition to being stored in a table of some sort.
View 3 Replies
May 24, 2010
I'm having a bit of an issue receiving a stream of serial data and displaying the data real-time in my GUI. I am fairly new to VB.Here's what I'm trying to achieve: I have an I2C device (bank of LED's) connected to my Arduino. Using the VB.NET (2010) GUI I request which LED I want on (via buttons) and the I2C device then sends a reply confirming which LED actually turned on (basic feedback). Ok, sounds great right? Here's where I get issues. Well when I try to read the serial data sent to VB and display the real-time stream on the GUI, a) I get a bit of a mess as an output (values are ok, just spewn across GUI) and b) when I select a new LED to turn on, the GUI data does not refresh to this change. The stream being sent from the Arduino is ok, I looked at the data in a serial monitor.
[Code]...
View 2 Replies
Jun 15, 2011
I've use VB net to create a application that can download the real-time data from a device for every second. Now I want to upload the data to a website in real time. (So some who is far away, can also check the data through the website)
View 3 Replies
Jan 30, 2009
HBasically I will have two forms. Form1 will control form2 which is the media display. Form2 will give back the media status and info back to form1 in someway. I was thinking of creating properties in form2 and having form1 polling these values to display the elapse run time etc... ideally i wish to have form2 somehow send events back with data when it values gets updated.
View 1 Replies
Nov 24, 2009
I am working on a project that is able to display real time data from sensors from micro-controller. I am able to do so by sending the data through the serial port and then use vb 2005 to show the data. However, I want to save those data from vb 2005 to excel. How am I able to do it ? I am able to use vb to insert data to excel step by step, cell by cell using the following codes.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim oExcel As Object
Dim oBook As Object
Dim oSheet As Object
[code]....
Lets say TextBox1.Text and TextBox2.Text is my real time data. How do I save it to the excel sheet displaying the data in cell A2, A3, A4 when the time goes by. Eg. If I want to save TextBox1.Text to excel it would be, the data in the 1st seconds in cell A2, data in the 2nd seconds in A3, 3rd seconds A4, 4th seconds in A5, A6 and so on...
View 3 Replies
May 2, 2009
I am busy with a VB2008 EXPRESS program that reads is data via a network cable. Saving the data on the same computer as my program is not a problem, but I must also make this data available to other users in the network and update their screens in real time. In other words I need a COPY of my running program on each networked computer when requested by the user in the network. I have looked at SQL, XML pages and inheritance. But I am confused, what is the best way???
View 13 Replies
Jan 5, 2012
I m into automation development of FMCG products using Micro-controllers. I get real time data Barcode 2D from TCP/IP connection. My task is to compare the result do some Computation with them and Store the incoming Barcode and results into a Excel sheet in a folder. I m successful with the basic working. Am currently working at slow speed of 1 barcode(22 char info) per second from the TCP/IP data (barcode scanner). Now, comes the real issue. I need to process atleast 5 barcodes per sec ( <200ms per process). I m partially successful with 3 Barcode per second(300 ms per process). so, thats like 300ms per processing. I need to achieve less than 200ms for entire processing. I have used threads and timers. but I m unable to achieve. Seems like storing in Excel takes more than 250ms. Since i come from micro controllers background 1msec is a lotta time to process for me. I m not sure how much time does it take and trust me i find it difficult to guage the time here.
View 1 Replies
Jun 22, 2010
I have an Excel based algo-trading app that needs to take in lots of real-time data, and make trading decisions based on the calculations driven by the data. It is not one of those "read-only" stock ticker kinda spreadsheets.I created a COM object with VB.NET that runs in its own thread space which collects data from a socket, and when the data is read it raises an Event with data attached. In Excel VBA, the event handler parses the data, puts them to the right places on the spreadsheet to feed calculations (so far it sounds like a stock ticker app), and then, based on the results of the various calculations it does something.The problem is that when the user starts to click around the spreadsheet while there is large amount of data coming, the event handler's cell updating breaks apart. If the app is left alone without user action, it stands well. My frustration comes from not understanding what happens to the main thread when a user clicks around. Either the event handler blocks the user action, or the user action blocks the event handler (under which case I will put in some queuing facility). But I just don't see how user action can break the code (like causing VBA to stop executing)
View 9 Replies
Mar 7, 2011
My requirement is to graph (scatter graph) data from 2 arrays. I can now connect the data from the array and use it on the chart. My question is, how do I set the graph's X- and Y- axes to show consistency in their intervals?
[Code]...
View 1 Replies
Jan 8, 2010
I'm pulling data from a Lotus Notes database, this works fine but when I change the data and pull it again, it doesn't take the changes, a restart solves this so it must be getting cached somewhere, how do I prevent it?[code]...
View 7 Replies
Jul 27, 2009
Is it possible to cache dataset which is accessible globally.Example: One windows service creates a dataset and caches it.Another Web Application and Windows application references that cache and populates in datagrid.
View 2 Replies
Feb 17, 2012
When i'm tryed to print Data chart the resolution of the chart changed as shown:
View 3 Replies
Oct 5, 2009
A quick question on caching dataset objects. How can I know if the data is changed in Sql when caching data? I don't want to specify time constraints but used a strategy where data is changed in sql and I have to refresh my cache?
View 1 Replies
Feb 27, 2009
We have data that's updated nightly in a database residing in the same instance as my app's database. So to save on database calls, I want to cache this static-for-the-day data into a List(Of MyObject). From a theory point of view, should this cached List(Of ) be cached in the presentation layer code, via a global variable? Should it be in a global variable in the .DLL?I'm thinking in the .DLL, because I created a service layer, which is exposed publicly to the GUI and makes calls to the data access layer inside the .DLL:
Public Shared Function Search(ByVal criteria As Core.Other.Customer) As List(Of Core.Other.Customer)
' TODO: Check the customer cache to see if it has been populated yet. If not, populate it.
If 1 = 1 Then
[code]....
View 3 Replies
Jul 2, 2010
I'm using interop.msxml2.dll to open XML and txt files off an Internet server. The response that is received from the server is stored in my application's variables. I've recently noticed that the application doesn't always update the information when it goes to download a file that it has already downloaded in the past. For example, if it downloaded a file off the server when it started up, then when it attempted to download the new, changed file 5 minutes later, it would still return the same value as the first one. Even after closing the application, it would still return the incorrect, older value. How to stop this "caching" of data, and only allow the program to download the latest file off the server.
View 1 Replies
Aug 11, 2011
well until a few day ago. I don't know what I have introduced to cause the problem but now, whenever I load the project, VS 2010 (SP1) crahes. If I delete the project's suo file, the project loads (really quickly) and all is well until I exitVS 2010. When I re-run it and try to load the project, it crashes again unless I delete the suo file.The program can be built for x64 and x86. Now, when I reload the project (after deleting the suo file), it comes up in Debug - Any CPU mode. I can change from Debug to Release and from Any CPU to x86 but if I try and change from x86 to x64, VS 2010 crashes.This is not always the case though. If I build the x86 version and then switch to x64, all is well and I can build the x64 version. Obviously, there's something wonky going on.
View 7 Replies
May 24, 2010
Is there any open-source component for VB.NET that offers real-time spelling (i.e., as you type) much like word? I found some free and open source components but without that ability.
View 2 Replies
Apr 7, 2010
How can I display a running stopwatch on my form? I am creating a timer but I do not want to use the timer class.
View 4 Replies
