You would simply build eight graphical pictures of the knob with the pointer in each of the positions. The object called position would be converted into the number 1 to 8 and the corresponding graphic file knob1.gif through knob8.gif would be displayed. Again all the device processor has to do is send the position object to the web server coprocessor whenever it changes. HTML has radio buttons and check boxes. For these to be emitted by an embedded system, the object must return a text string checked when the box should be checked.
Objects can be more complicated.
This could be data input from a form, or the click of a button. Forms allow a browser to package up text and numbers and list selections, radio buttons and check boxes and send them to a web server. Back to the thermostat, the device processor s job is to make the room temperature match the set point that came in from the web. The next time the device processor goes to read the setpoint and the fan, it will have the new numbers. Reading objects by the device processor use basically the same command structure as sending objects.