As almost all measured variables in fluid technology change in an analogue manner, they must first be divided up into equal size sections (steps) for digital measured value acquisition. This action can (exceptionally) be mechanical (incremental position measurement). In the majority of cases the outputs analogue electrical variables, also in digital measured value acquisition; these variables are then converted in an A/D converter into digital signals(Figure D 26).

Figure D 26: Measured value acquisition with A/D converter