If you are observing a security violation when attempting to build the VisionPro Sample Code, it might be caused by the user currently logged not having write access privelges to the sample code output directories. One workaround is to change the security permissions for the user currently logged in. Right-click on C:\Program Files\Microsoft Visual Studio 8\Common7\IDE\devenv.exe, select the Security tab and change the permissions for the affected user.

This section describes limitations in displaying images.

If you specify the 'fade effect' for menu transitions and tool tips using the Windows Display Properties control panel, then right-clicking in a live video display may slow the frame rate in that display dramatically.

Workaround:

You can prevent this problem from happening by not specifying the 'fade effect' for menu and tool tip transitions.

Attempting to save an image from a VisionPro display control by right-clicking on the image and selecting Save Image To File... may fail for large images. If the message Error Saving Image: Unable to create the requested DIB section appears, the image is too large to be saved.

This section describes limitations of the documentation in VisionPro 9.3 SR1.

In some cases, the documentation displayed by Visual Studio's built-in code browser for VisionPro functions is improperly formatted. The properly formatted text is always present in the online documentation, which you can access directly from Visual Studio (with a single click if you have Dynamic Help enabled).

This section describes limitations of the DS1000 series sensor in VisionPro 9.3 SR1.

All z-height information displayed for the right half of Range With Grey Images acquired by a DS1000 series sensor should be ignored. The right half of such images contains intensity data, not height data.

This section describes limitations of the DS900 series sensor in VisionPro 9.3 SR1.

All z-height information displayed for the right half of Range With Grey Images acquired by a DS900 series sensor should be ignored. The right half of such images contains intensity data, not height data.

This section describes limitations of the VisionPro development environment.

Because of how System.Windows.Forms.Control.Dispose() is implemented, a WinForms VisionPro application may experience errors when it tries to shut down. This typically happens if the application uses any controls derived from System.Windows.Forms.AxHost. Many VisionPro controls derive from this base class. The errors are typically unhandled exceptions of type System.Reflection.TargetInvocationException or System.Runtime.InteropServices.InvalidComObjectException.

You can prevent these errors from happening by following these two steps:

Call Dispose on all controls that are contained within your controls before calling Dispose on your base class.

There are several ways to accomplish this. You can call Dispose inside your form’s Closing event, or you can do it inside the Dispose method. The following VB.NET sample code shows how to modify the Dispose method. The standard Dispose code has been augmented with an explicit call to Dispose for a contained CogDisplay control.

'Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
    If disposing Then
        If Not (components Is Nothing) Then
            components.Dispose()
        End If
        CogDisplay1.Dispose()  ‘ Explicit call to Dispose for contained CogDisplay
    End If
    MyBase.Dispose(disposing)
End Sub

'Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
    If disposing Then
        If Not (components Is Nothing) Then
            components.Dispose()
        End If
        CogDisplay1.Dispose()  ‘ Explicit call to Dispose for contained CogDisplay
    End If
    MyBase.Dispose(disposing)
End Sub

The equivalent C# code is:

protected override void Dispose( bool disposing )
{
  if( disposing )
  {
    if (components != null) 
      components.Dispose();

    cogDisplay1.Dispose();  // Explicit call to Dispose for contained CogDisplay
  }
  base.Dispose( disposing );
}

protected override void Dispose( bool disposing )
{
  if( disposing )
  {
    if (components != null) 
      components.Dispose();

    cogDisplay1.Dispose();  // Explicit call to Dispose for contained CogDisplay
  }
  base.Dispose( disposing );
}

You should be sure to call Dispose for all contained VisionPro controls and for any contained controls that may themselves contain VisionPro controls. You should take this action inside your controls, inside your forms, and inside any other class of yours that is derived from System.Windows.Forms.Control.

Avoid accessing any control derived from System.Windows.Forms.AxHost inside your Dispose method.

If you must access such a control, you should make sure that it is still valid before using it. You can do this efficiently by testing that GetOcx doesn’t return ‘Nothing’ (or null, in C#). You must do this because the attached ocx will sometimes be destroyed before your Dispose method is called.

Here is a VB.NET example:

'Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
    If disposing Then
        If Not (components Is Nothing) Then
            components.Dispose()
        End If
        If Not (CogDisplay1.GetOcx() Is Nothing) Then
            Params.LastZoom = CogDisplay1.Zoom  ‘ Save the last Zoom setting
        EndIf
        CogDisplay1.Dispose()  ‘ Explicit call to Dispose for contained CogDisplay
    End If
    MyBase.Dispose(disposing)
End Sub

'Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
    If disposing Then
        If Not (components Is Nothing) Then
            components.Dispose()
        End If
        If Not (CogDisplay1.GetOcx() Is Nothing) Then
            Params.LastZoom = CogDisplay1.Zoom  ‘ Save the last Zoom setting
        EndIf
        CogDisplay1.Dispose()  ‘ Explicit call to Dispose for contained CogDisplay
    End If
    MyBase.Dispose(disposing)
End Sub

The equivalent C# code is:

protected override void Dispose( bool disposing )
{
  if( disposing )
  {
    if( components != null )
      components.Dispose();

    if (cogDisplay1.GetOcx() != null)
      Params.LastZoom = cogDisplay1.Zoom;  // Save the last Zoom setting
    cogDisplay1.Dispose();  // Explicit call to Dispose for contained CogDisplay
  }
  base.Dispose( disposing );
}

protected override void Dispose( bool disposing )
{
  if( disposing )
  {
    if( components != null )
      components.Dispose();

    if (cogDisplay1.GetOcx() != null)
      Params.LastZoom = cogDisplay1.Zoom;  // Save the last Zoom setting
    cogDisplay1.Dispose();  // Explicit call to Dispose for contained CogDisplay
  }
  base.Dispose( disposing );
}

Notice that you do not need to check GetOcx if you only intend to call Dispose on the AxHost-derived control.

If you save a tool that references a large image (around 200 MB or more) you may get an out of memory exception. This exception may occur when you are using the VisionPro API, or QuickBuild.

Windows XP supports a boot.ini flag (/3GB) that can be used to expand the amount of virtual memory available to processes. Executables that support this expansion must be marked with the "LARGEADDRESSAWARE" flag, which can be done either with a linker flag or with the editbin utility.

VisionPro does not support this mode of operation. VisionPro applications must not be marked as LARGEADDRESSAWARE. However, VisionPro applications should have no problem running on a system that has the /3GB flag enabled as long as the they are not marked as LARGEADDRESSAWARE.

For more information on this Windows feature, see the Microsoft article Memory Support and Windows Operating Systems .

Microsoft 32-bit OS's have a limitation of 2 GB of virtual address space per application and this limit can be easily reached when using large images in a VisionPro application. Refer to Technical Bulletin 07-001 if you are experiencing a System Out of Memory exception on a 32-bit operating system. Alternatively, use a 64-bit operating system where this limitation does not exist.

Whenever you create an event handler for a VisionPro event, you need to be aware that if the job whose events you are handling is being run by QuickBuild, the events may be fired at times that you do not expect. For example, QuickBuild enables and disables triggers internally, so the Changed event is fired. Any event handler that you write, especially if you are writing it as part of a script, must be prepared to handle unexpected events.

This section describes limitations concerning GigE Vision image acquisition.

Whenever a driver is replaced on a network interface card (NIC), the NIC configuration is returned to its default setting, established either by the manufacturer or the operating system. This is expected behavior.

This section describes limitations in graphics.

Whenever you add a graphic object as the child of another graphic object, you must specify "$" for the child object's coordinate space name.

When you use a scale handle to interactively resize a composite graphic, VisionPro uses the minimum of the new x- or y-scale, which means that if you make the enclosing rectangle narrower in one direction, the entire image will get smaller.

This section describes limitations of the Image and Mask Editor in VisionPro 9.3 SR1.

This release does not support launching the Cognex Image and Mask Editor when launched from the IDB Editor on 64-bit operating systems.

This describes limitations you should be aware of when installing VisionPro.

Cognex does not support the installation of the 32-bit version of VisionPro on any 64-bit operating system, although the VisionPro installer does not prevent this.

Because Cognex acuReader III Version 1.2 (and all previous versions), Cognex FiberInspect Version 1.3.2 (and all previous versions), and Cognex Font Editor Version 1.1 are built on older versions of VisionPro, this release of VisionPro cannot coexist with these software products on the same PC. If they are installed in your system, you must uninstall acuReader III, FiberInspect, and Cognex Font Editor before you install VisionPro. You must uninstall VisionPro before you can install acuReader III, FiberInspect, or Cognex Font Editor on the same machine.

VisionPro can be installed on the same system as CVL versions 6.0 and newer. VisionPro may not work correctly if installed on systems with older CVL versions. Additionally, versions of CVL earlier than 5.5.1 may not work correctly on systems that have VisionPro installed.

This section describes miscellaneous limitations in VisionPro 9.3 SR1.

Virus scanning software that scans your PC memory and disk in the background may decrease the performance of your VisionPro-based application.

Workaround:

Disable background virus scanning or quit the virus scanning software while the VisionPro-based application is running.

VisionPro does not support changing languages while your vision application is running.

Workaround:

Exit VisionPro, change the language you are using, then restart VisionPro.

This section describes Model Maker limitations in VisionPro 9.3 SR1.

When you use Model Maker's Compose Contour feature, you cannot change the direction of a line segment or elliptical arc as you add it to the contour. This means, for example, that attempting to compose an L-shaped contour from a line segment that goes from (10,10) to (30,10) and a line segment that goes from (10,10) to (10,30) is not possible.

Workaround:

You can work around this problem by manually re-ordering the end points of the segment before adding it to the contour.

This section describes limitations of discrete I/O in VisionPro 9.3 SR1.

In some cases, the actual pulse signal can be shorter than the PulseDuration. For example, if you specify a 500 ms pulse duration, as shown below:

OutputLine.PulseDuration = 500 
OutputLine.PulseMode = CogOutputLinePulseModeConstants.High
OutputLine.Value = True

OutputLine.PulseDuration = 500 
OutputLine.PulseMode = CogOutputLinePulseModeConstants.High
OutputLine.Value = True

the resulting pulse may actually be as short as 490 ms in duration.

This behavior is a known limitation of operating system timers, and affects all Cognex hardware platforms that support the property. This problem is also known to occur more frequently when sending output pulses on multiple lines.

Workaround:

If your application requires an absolute minimum expected pulse duration, the workaround for this problem is to specify a value that is 1 ms longer than the actual desired pulse width. This will bump actual the pulse width to the next interval that matches the granularity of the multimedia timer.

In addition, reducing the multimedia timer period to 1 ms using the Microsoft Win32 API call timeBeginPeriod(1) can improve pulse accuracy. However, if you use this method, be aware that modifying the timer will affect overall system performance because this will result in timer interrupts needing to be serviced more frequently.

This section describes limitations of QuickBuild in VisionPro 9.3 SR1.

Adding items into Posted Items using the Property Browser supports adding Properties but not Methods. Even though Methods are shown in the Property Browser (i.e. CogBlobTool.Region.CogPolygon.GetVertexX) and the browser allows the item to be added, no value will be returned when user result is available (see UserResultAvailable event handler).

If you load a QuickBuild application created with a version of QuickBuild prior to VisionPro 4.1, the I/O queue size or the Posted Items list size may have been reset to the default.

This section describes limitations of sample code in VisionPro 9.3 SR1.

Sample applications containing the following functionality are not supported on the 64-bit operating systems:

• Model Maker
• CogAcqFifoEdit
• OCV
• OCV Font Editor

This section describes miscellaneous vision tool limitations in VisionPro 9.3 SR1.

The GetPose and GetPoseWithRespectToPattern functions return the location of a character verified by the OCV tool. The results returned by these functions are accurate to the nearest whole pixel in both the x- and y-direction. You cannot use the OCV tool to obtain sub-pixel character locations in the run-time image.

This section describes limitations of the OCV tool in VisionPro 9.3 SR1.

Clicking the "?" button in the OCV tool edit control will display a message that VisionPro is unable to locate the online help and that re-installing the product might resolve the issue. The OCV tool edit control, however, does not support access to the online documentation supported by most other tool edit controls. Re-installing VisionPro will not resolve the issue.

The OCV tool edit control and OCV Font Editor are not supported on 64-bit operating systems.

Any .vpp file containing an OCV tool that was saved without images and results (which happens if you specify CogSerializationOptionsConstants when calling SaveObjectToFile or if you specify "Save the tool without images and results" when saving a tool using QuickBuild or the tool edit control), cannot be reloaded, if that file was saved using a version of VisionPro before 3.4.

There is no workaround for this problem. Files saved under these conditions cannot be reloaded by any version of VisionPro. Files saved with VisionPro version 3.4 can be reloaded.

This section describes limitations of the PatMax tool in VisionPro 9.3 SR1.

PMAlign tool error strings always appear in current operating system regardless of what language you have configured QuickBuild to use.