XLL+ Class Library (7.0)

Requirements for asynchronous functions


Excel version
This model uses Excel's RTD mechanism, which is only available in Excel XP upwards. It cannot be used with Excel 97 or Excel 2000.
Operating system
The model requires Windows 2000 or above, since Windows 98 does not support multi-threading.


The deliverables required for the projects discussed here include the following files and folders:

File Description
Samples/AvgOptAsync Source code for the asynchronous Excel add-in discussed below.
Samples/XllRtdLink Source code for the RTD server discussed below.
Samples/Bin/XllRtdLink.dll Compiled RTD server module.


The model uses a COM module (XllRtdLink.dll) to support Excel's RTD mechanism. You should register the RTD server module XllRtdLink.dll, in one of the following ways:

  1. Use REGSVR32 at the command line, e.g.

    REGSVR32 "C:\Servers\win32\XllRtdLink.dll"

    Ensure that you register the correct version of the DLL: on a machine with 64-bit Excel, you should register the 64-bit version of the file, which can be found in redist\x64, whereas on a machine with 32-bit Excel, you should register the 32-bit version of the file, which can be found in redist\win32.

  2. Build the project Servers\XllRtdLink\XllRtdLink.sln. Choose either the Debug or the Release MinDependency build.

Note: The XllRtdLink DLL is automatically registered when you install the XLL+ toolkit on a development machine. You only need to register it yourself when you deploy XLLs with asynchronous functions to another machine.

Next: How asynchronous functions work >>