To add a spreadsheet to a Display board, follow the steps below:
to add the web link to the display board:
place test.html in ssl data - global admin
enter following URL in the display board
http://192.168.0.1:81/test.html
if you want to display a graph create a folder to store the image and specify that in the URL
http://http://192.168.0.1:81/test/test.html