Welcome to TFP!
Before running Test Pool Pilot you need to make sure that the unit has the cell turned on. When the cell is off (for any reason) the volts reading will always be zero. The best way to insure the cell is on is to press boost, and wait about 30 seconds for the boost more to fully engage. Of course if there is some error message showing in the display, that can over-ride things and turn the cell off.
Also, is there something going wrong that makes you suspect that the SWG (PoolPilot) is not working? The more context you can give, the more we can help you.