according to VDI 3260
Graphic description of the movement sequence of hydraulic systems from which the individual steps and their sequence for a switching cycle are defined, as can be seen in (Figure F 42). This representation of the individual functions can be further supplemented by the oil consumption diagram and the accumulator volume diagram.
As at the same time signals that trigger a function can be added, mostly with their signal elements, the function diagram also represents a graphic link between the signal circuit for the system and the power circuit. The function diagram eases the planning and the commissioning of a system as well as troubleshooting.
The task formulation on which the diagram is based is the same as for the flow diagram and the function chart.
Figure F 42: Function diagram according to VDI 3260