Tempo refers to the amount of time you spend on certain portions of a lift.

Are you sure that Waterbury has listed a "30x0" tempo?? Seems a bit odd to me.

Generally tempo schemes are set up in two or three parts... negative, pause (if any), and positive. So a 3-0-1 tempo would be a 3 second negative, 0 pause, and 1 second positive. In simpler terms, take squat for exampe, 3 seomds on the way down, switch directions with no pause (and no bouncing), and 1 second to come back up. That can also be set up as a 3-1 tempo (eliminating the 0 for the no pause).