A combine harvester hydraulic system having a valve which automatically routes hydraulic fluid from a combine fluid supply line to a combine fluid return line when the combine fluid supply line is not coupled to a hydraulic line of a harvesting assembly. The regeneration device includes a plurality of first temperature detectors arranged in casings to detect the temperature in each casing and a second temperature detector for detecting the temperature of the exhaust gas. The plurality of graphical icons may include a plurality of clause-specific icons that identify clauses for the database query and a plurality of table icons that identify sets of data in the database.