I will give you some indications...
On the Front Panel, place a Waveform Graph, which is in the COntrols Palette, under Graphs.
Create two numeric controls, one called Voltage and the other Resistance. The control can be a numeric control or a dial.
On the Block diagram, use the divide function and wire the Voltage control at the top terminal and the resistance to the bottom terminal.
You can wrap this up inside a While loop. Simply place a STOP button on the front panel and wire it to the loop conditional terminal (stop sign). Then wire the output of the divide function to outside the while loop. Enable indexing at the tunnel exiting the loop and wire the array to the Waveform Graph.
