You can check this from the QVS reference manual.
20.7 ASP timeouts for very large QlikView documents
When using the QlikView AJAX ZFC with large QlikView documents, the asp code
might sometimes require that you increase the asp timeout. This can be made in two
ways, either programmatically or by customizing the IIS.
By setting the Server.ScriptTimeout property in your code, such as:
<%Server.ScriptTimeout = 180 %>, where the numeric value is the number
of seconds that the current script will be executed.
To set the timeout in the IIS, open the IIS Management Console, open
Properties for the folder containing the asp code, go to the Directory or
Virtual Directory page (depends on what type of folder you use), press the
Configuration button to open the Application Configuration dialog, go
to the Options page where you find the edit box for the ASP Script Timeout.