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I think you'll need to post a little more information to get much help. That's a pretty difficult question to answer without code. Still, when you say CAN, are you referring to the bus protocol often used in automobiles, trucks, and various equipment? If so, who wrote your communications DLL? If it's what I'm thinking, you need to take a look at setting filters to limit the amount of incomming data. CAN data running at full speed (about 1 meg I think) is quite a bit of callbacks. If filtering isn't an option in the supplied DLL, you could write your own in ATL COM. This should be much faster and then you could post up only the messages you really need to your application. If we're on the same page, you may want to consider another provider for your communications DLL like possibly Noregon Systems out of Winston Salem, NC.
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Ok, I will give some more info. CAN means the busprotocol which is used in automotiv industries. The DLL is written by the manufacturer of the industrial computer (using the Win DDK), where the CAN chip is build in.Of cause this is not only the DLL but also a system driver for this hardware. The DLL is only the interface. We used the CANbus with 250 kBaud which enables us to read the incomming Data with 1 ms resolution and we need all the data because we have to control a very dynamical process.
Next I will give some code how I have impleneted this:
using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.Threading;
using System.Security;
namespace CanOpen
{
// First of all I define the data structure for the callback function
// Before this was public byte oldData[] and public byte newData[]
// But the structure of the Callback function works with byte oldData[8] and
// byte newData[8] and I didn't know how to realize this in C#
public struct NewDataType
{
public int node;
public byte oldData1,
oldData2,
oldData3,
oldData4,
oldData5,
oldData6,
oldData7,
oldData8; //
public byte newData1,
newData2,
newData3,
newData4,
newData5,
newData6,
newData7,
newData8; //;
public int dataLen; //max. 8 bytes (= max. PDO data length)
public PDOChannelType PDOChannel;
}
.....
// Next I define the delegate for the Calback function
delegate void DelegateUserCANNewInputData( ref NewDataType pNewData);
.....
// This is the function, which registers the callback function,
// I tried with and without SuppressUnmanagedCodeSecurity but it has no influence
[DllImport("canopen.dll"),SuppressUnmanagedCodeSecurity]
static extern int CANopenNewInputDataRegister(DelegateUserCANNewInputData
UserCANNewInputData);
.....
private void RegisterCallBackFunctions()
{
int RetCode;
DelegateUserCANNewInputData FptrUserCANNewInputData = new DelegateUserCANNewInputData
(UserCANNewInputData);
RetCode = CANopenNewInputDataRegister(FptrUserCANNewInputData);
}
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Ok, I will give some more info. CAN means the busprotocol which is used in automotiv industries. The DLL is written by the manufacturer of the industrial computer (using the Win DDK), where the CAN chip is build in.Of cause this is not only the DLL but also a system driver for this hardware. The DLL is only the interface. We used the CANbus with 250 kBaud which enables us to read the incomming Data (PDOs) with 1 ms resolution and we need all the data because we have to control a very dynamical process.
Next I will give some code how I have impleneted this:
using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.Threading;
using System.Security;
namespace CanOpen
{
// First of all I define the data structur for the callback function
// Before this was public byte oldData[] and public byte newData[]
// But the structure of the Callback function works with byte oldData[8] and
// byte newData[8] and I didn't know how to realize this in C#
public struct NewDataType
{
public int node;
public byte oldData1,
oldData2,
oldData3,
oldData4,
oldData5,
oldData6,
oldData7,
oldData8; //
public byte newData1,
newData2,
newData3,
newData4,
newData5,
newData6,
newData7,
newData8; //;
public int dataLen; //max. 8 bytes (= max. PDO data length)
public PDOChannelType PDOChannel;
}
public class VCanOpen
{
.....
// Next I define the delegate for the Callback function
delegate void DelegateUserCANNewInputData( ref NewDataType pNewData);
.....
// This is the function, which registers the callback function,
// I tried with and without SuppressUnmanagedCodeSecurity but it has no influence
[DllImport("canopen.dll"),SuppressUnmanagedCodeSecurity]
static extern int CANopenNewInputDataRegister(DelegateUserCANNewInputData
UserCANNewInputData);
.....
// During the initialization of the CANOpen class
private void RegisterCallBackFunctions()
{
int RetCode;
DelegateUserCANNewInputData FptrUserCANNewInputData = new DelegateUserCANNewInputData
(UserCANNewInputData);
RetCode = CANopenNewInputDataRegister(FptrUserCANNewInputData);
}
.....
// This is the callback function which will be called by the DLL
void UserCANNewInputData(ref NewDataType pNewData)
{
// Do something or nothing
}
....
} // class VCanOpen
} // namespace CanOpen
Regards
Michael
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Matt is right, do you really need all of that data? Are you using RP1210A? If so, filter out what you don't need at the driver/dll layer and don't allow all of the data to come up. CAN is a very fast protocol and on a loaded bus can bring almost any computer to its knees if it tries to process every message.
david
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I really need all this data. I need all the PDOs coming in for this measurement data. The data is already filtered in the system driver. And there is only one other node which sends data. At the end I need to record the data with a frequncy of 1 kHz. But even with 50 ms the system is not more usable. Again, before we use Delphi and it works very well. Only 5 % of CPU is used with Delphi.
Another question? If it is so, as you described, maybe .NET is not the future solution for applications which must handle a big amount of data in short time.
regards,
Michael
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Couple of thoughts:
1) Try using windows messaging instead of callbacks. Windows messaging is much more efficient and optimized by the OS.
2) Try offloading the callback to another thread.
As for Delphi, I've never used it.
What is your busload on the CAN network you're trying to read everything from and what speed are you running (250, 500, 1M, etc)? I can tell you that nearing 70-100% busload on a 250k CAN network will make a boat anchor out of my PC, if it tries to process all the data. Not to mention you are trying to record it... which requires flushing to a file every now and then.
David
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In the area of raw ability to crunch numbers, how does .NET technology compare with old fashioned C++? So for example if I wanted to render a fractal would CLR do that well? The reson is that .NET will lend itself perfectly to user customisation of modules in my graphics program because I can have it recompile after the user has edited the code, allowing huge flexibility. But is .net up to the task?
Joel Holdsworth
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I used an ActiveX Object in my VB6 project like this:
obj = CreateObject("AAA.BBB");
When I tried to do the same thing in C# .Net project, I can't not find this object in "Add reference" dialog.
Does anyone know why?
Thanks in advance!
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Assuming you already looked under the "COM" tab of the add reference dialog box, the Component name used when creating a late bound control in VB6 using CreateObject often differs from the name displayed in the add reference dialog box. As an example, to create an Excel application reference in VB6, you could do this:
xl = CreateObject("Excel.Application")
but when you look in the VS.NET add reference dialog box, it is described as the "Microsoft Excel 9.0 Object Library".
What a piece of work is man, how noble in reason, how infinite in faculties, in form and moving how express and admirable . . . and yet to me, what is this quintessence of dust? -- Hamlet, Act II, Scene ii.
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Hi guys,
Have been handed a job to do from down on high....my company are looking at using ASP.NET for some new modules in an existing ASP classic application.
My boss is concerned with the end-user issues connected with .NET - not the benefits, but the sort of SysAdmin problems that installing the framework might create, such as existing apps not working etc....
Can anybody share their experiences, or point me to some resources on the subject?
"Now I guess I'll sit back and watch people misinterpret what I just said......"
Christian Graus At The Soapbox
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As far as the clients are concerned there should be no issues (just as there are no issues if you point your browser to a page that ends with a .aspx extension). You only have to be concerned with the server machines that are hosting ASP.NET, which must of course have .NET installed on them.
Kevin
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Classic ASP can co-exist peacefully with ASP.NET on the same machine, provided, of course, that the machine meets all the other requirements to run the .NET framework and ASP.NET.
That being said, there are potential issues if you try to integrate ASP and ASP.NET together, since they don't share session state, application state and so on. There are articles on how to make them work together if you look around.
What a piece of work is man, how noble in reason, how infinite in faculties, in form and moving how express and admirable . . . and yet to me, what is this quintessence of dust? -- Hamlet, Act II, Scene ii.
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But, isn't there some issues with passing Application/Session variables from ASP applications to ASP.NET applications.
Norman Fung
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Yes, as I mentioned, "there are potential issues if you try to integrate ASP and ASP.NET together, since they don't share session state, application state... "
That can be overcome, to an extent, by not relying on Application and Session if you have to put the two together. One could use query strings, hidden forms, etc. It's more work, but it might be a way to gradually transition an app from Classic to .NET.
What a piece of work is man, how noble in reason, how infinite in faculties, in form and moving how express and admirable . . . and yet to me, what is this quintessence of dust? -- Hamlet, Act II, Scene ii.
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We are currently scoping a new (smallish) project, and need to make decision as to whether we develop it in .Net or C++.
Does anyone know of any statistics that detail the distribution of the .Net framework on desktop systems?
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Why not just have your applications installation package install the .NET Framework. It is freely redistributable.
EuroCPian Spring 2004 Get Together[^]
"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar
"Get in touch with your Inner Capitalist - I wish you much success!" -- Christopher Duncan, Lounge 9-Feb-2004
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I've been in the same situation. If your software is distributed over the web to end users you have no control over, .NET is a HUGE requirement. I've asked this question in other forums and to some MS people; it's really strange how some people have a hard time understanding that .NET is indeed a very difficult pill for end users to swallow, thanks to it being over 21 MB.
My thought is this:
.NET will be everywhere by 2007. Until then, it's a guessing game; while a vast majority of desktops have XP, only some of them will have .NET. If your product is small, and will be finished within a year, and will be distributed over the web, I'd say use C or C++.
If your product is fairly large project that will take a year or more to develop, or will be distributed on a physical media, then yes, write it in a .NET language for productivity's sake. By the time your product is released, many more users will have the .NET framework installed already, and you'd be even closer to Longhorn, when everyone will have the framework installed.
My rant is that MS needs to get .NET to the masses sooner than Longhorn. If they would just bundle it with Office or IE, questions like these wouldn't arise and they'd get more developers writing .NET-based software.
The graveyards are filled with indispensible men.
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Hi
i have a strange problem:
i use code like this:
ODBCConnection cnn = new ODBCConnection("... cnn string ...");
ODBCDataAdapter da = new ODBCDataAdapter("select * from tbl left join tbl2
on tbl.refid = tbl2.id", cnn);
DataTable dt = new DataTable;
DateTime t = Now();
da.Fill(dt);
TimeSpan ts = Now.Substruct(t);
Trace....... Show the ts.
.....
i use this code in 2 programs:
(the remoting server is a console app.)
position:
Time
1. remoting server program on a marshaled object
in static method.
8.7 seconds.
2. the same server, but in the main file.
5.4 seconds
3. the client, in the remoting object (the same
method as 1, but i know here it is not the same
remoting object).
4.2 seconds.
4. different console program( that not using any
remoting, built to the test.)
0.5 second !
u see a huge changes between these methods.
I operate the 2 programs (remoting and test) concurrently and the results
was the same +-.
so i assume it is the remoting that affect the Fill method.
but why ??
what could be the reason ??
if any1 want i will send him the remoting configuration section in the
config file so he might watch it...
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Hello,
Does anyone know about How to write a code for custom controls which the user can do drag and drop feature while browsing the page. For Example i am having a login control in my let hand side, at the time of browsing the user can change the location to right hand side by just doing drag and drop facility.
Is it possible to do? Any documents for this or any procedures?
Thanks in advance.
Best regds,
Kandasamy.
" BE extremely passionate about what you do. Combine it with patience, confidence in your abilities and a dedicated team of professionals. Sucess is inevitable "
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Hello All,
I need a technical help, which is related to Performance and Application Design issue.
I have a function, which is accessible from a page alone. Now the question is which is the best approach - To keep the function in my Code-behind file itself or keeping it in a class module and call it.
Which is the best way to do. For this if you got any supportive documents also pls do send me ASAP.
Thanks in Advance.
Regds,
Kandasamy.
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There are several related questions that point in one direction or the other. Primarily, where and how often do you intend to use a function, and what information does the function act upon? For example, if a function returns a SqlDataReader that lists a customer's recent orders by customer ID, the function probably belongs in a class like "OrdersData"... thus making it available to any method within the entire application. If, on the other hand, it is some kind of static/shared function, for example, a function that takes a datetime value and returns a formatted, human-readable date & time string, and you expect it to be called several times in several different classes, you could have a class library of "helper functions". Or, if it is a function used only by one page for one reason, leave it as a member of the page class.
But then again, I could be wrong.
What a piece of work is man, how noble in reason, how infinite in faculties, in form and moving how express and admirable . . . and yet to me, what is this quintessence of dust? -- Hamlet, Act II, Scene ii.
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My windows service is strong names by putting
<assembly: assemblykeyfileattribute("c:\mykeyfile.snk")=""> in assemblyinfor.vb
But when I write a setup and deployment package for it and set it up I get the error :
Unable to create an instance of (my installer class) installer type. ->Exception has been thrown by the target of an invocation.-> Security Error
Any one got any idea how to get round this?
MOO!!
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Don't know if this is a known issue, but Application.EnableVisualStyles does not work on vertical scrollbars (I assume it won't work on horizontal scrollbars either). Oddly, if I use a create .manifest file for my .exe, the vertical scrollbars will indeed get the XP Visual Style.
The graveyards are filled with indispensible men.
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