The issue is that there is no software available for the template to 'listen' to the IP packets emitted by your IP datalogger. The IP datalogger is hardwired to send info to Weatherlink.com (likely through an HTTP GET like WeatherUnderground RapidFire uses, or through some other proprietary protocol they've not disclosed). That's why the template set needs the weather software (running behind your local router) to connect to the IP datalogger, fetch the packets, process the data, and feed your website with FTP.