I have a tip for all people who want to control their interface card from a webserver.
Create a console application for controlling the card and starting a namedpipeserver.
This application can send (and receive) data from the interface card.
And this application can receive information fron other programs on the same computer.
when this namedpipe server recognises a command you defined you can do a certain action on a port.
This program can also monitor the input ports for changes.
Create a .net webservice with a few methodes like SetPort(int output, Boolean value)
And in this methode you connect to the named pipe and send the command.
This way you can pretty much secure your control interface from the internet.
And it works in a lot off browsers.
You could off course also make a aspx page with buttons that also opens a namedpipe connection.