Hello Janus,
I'm glad you found my project interesting. I have visited your site. PLC is not as astonishing as all the photos from your journeys. Very impressive!
I also started with placing SSI scripts and the htm pages on the PLC. I have, however, quickly noticed it is an outdated technology. A page placed at the server must be refreshed each time you want to have new data. That is not an user experience of our dreams.
It is, in my opinion, much more effective to have a web page stored locally, on the device which you use (PC, mobile phone etc.) and use AJAX request to fetch the data from the server. There are 2 main benefits of such an approach:
1. The page loads quicker, as it is available locally, so all the html, js, jpg/png files do not need to be downloaded,
2. The Ajax request can be launched at any time, many at once, can be controlled, cued, terminated etc.
Since it was difficult for me to write a script using HtmlRequest, which would work on all browsers, I used the jQuery library, which takes care for all the details. You can see an example page
here.
So I still use the READPI, WRITEPI commands but send requests in bulks. All the rest you see in the movie is a 'fancy' html and some graphics.
If the link above does not work or the example code is not clear enough, please let me know and I will try to write something better.
Cheers!