Truck PTO RPM

How do they work on modern bin trucks? When I last drove one about 20+ years ago every time I stopped I had to engage it for the lifter and ram to work, which was a pain in the arse.

Our tankers have them fitted, we just apply handbrake, flick switch on with clutch out then slowly let bring up the clutch and the revs increase on their own to operating speed (never looked at the rpm dial) without needing to manually adjust them with the CC.