Frigidaire Dishwasher - top rack dirty dishes

to add to the above,
how can i tell if there is the proper amount of water in the diswasher.
i am thinking that perhaps the water is to be the height of the little knob which protrudes upwards on the big flat round screen (part #65). reason being, is that i have no idea what else that knob could be for.

Also, with regards to the water heating. i think this only occurs on my dishwasher when set to pots & pans and think it is a timed thing vs temperature regulated. if i have this setting, what is the temperature that the element will try to heat the water too.
Many dishwashers heat the wash and/or rinse water to a higher temperature, as the cycle calls for it. In these cycles, the dishwasher pauses after it has filled with water, waiting for the water to reach the pre-set temperature. What happens next, depends, as follows:

On some units, the pause is timed and the unit continues after the allotted time.