Previously, I talked about using the LabVIEW ActiveX Server interface from within your ASP.NET application. I mentioned that the wonderful world of DCOM security, by default, would prevent you from calling LabVIEW through this interface. In this post, I'll explain how to configure the security settings to get this working.
These details assume you're running on Windows XP. If you are running on another version of Windows, the details are similar, although the exact steps might be off by a part or two. Feel free to email me if you have any problems.
First, go to your Control Panel->Adminstrative Tools (obviously, you'll need administrator rights to do this). Double click on Component Services.
Now drill down on the left folder view to Console Root->Component Services->Computers->My Computer->DCOM Config. You should now see a lot of icons of open cardboard boxes on the right. One of those is called LabVIEW Application. Right click and select Properties.
Almost there - go to the Security Tab and click on Edit for both Launch and Activation Permissions as well as Access Permissions. Now Add... the ASP.NET account to each one (typically called <machinename>\ASPNET). Make sure that this account has Local Launch, Activation and Access permissions.
That's it, you should now be able to launch LabVIEW from ASP.NET via the ActiveX Server interface. Next time we'll talk about that last tab - Identity - and what all this does to your security threat surface-area.