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Q143259: INFO: Remote Callback Works Only with 32-Bit Clients

Article: Q143259
Product(s): Microsoft Visual Basic for Windows
Version(s): 
Operating System(s): 
Keyword(s): kbVBp400 kbVBp500 kbVBp600 kbGrpDSVB
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, version 4.0 
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SUMMARY
=======

Remote Callback is a Remote Automation process in which a server uses an object
reference to a client class to asynchronously trigger its methods or change its
properties. Callback, or Asynchronous Notification, is especially useful for
monitoring real time data. For a Callback process to be successful, the client
need to be running on a 32-bit system.

MORE INFORMATION
================

When a Remote Automation server attempts to Callback a client object, it makes a
certain request. For instance, the server could request to trigger a client's
method. The automation proxy (AUTPRX32.DLL) on the server side carries this
request across the network. A method request by the automation proxy expects to
be met by the Automation Manager, and then served by the client. In other words,
the client needs to act as a server for the Callback to be successful. Because
16-bit systems cannot run the Automation Manager, they cannot run a Remote
Automation server. Therefore, a 16-bit client cannot be called back remotely.

REFERENCES
==========

- Enterprise Edition Documentation, Building Client/Server Applications,
  Chapter 7, Implementing OLE Servers

- Professional Edition Documentation, Creating OLE Servers, Chapter 3,
  Standards and Guidelines, Performance Issues

- CALLBACK Sample Application in ..\Samples\RemAuto\Callback

Additional query words: RemAuto kbRemote

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Keywords          : kbVBp400 kbVBp500 kbVBp600 kbGrpDSVB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600 kbVB400Search kbVB400
Issue type        : kbinfo

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