Siemens SINAMICS S120 System Manual page 173

Linearization of the valve
Valves with a fine control range are non-linear valves. An inverse characteristic is applied to
compensate the nonlinear characteristic of these valves. The transition for real valves is
rounded. For this reason, the transition range in the compensation is also rounded. The
rounding is based on a root characteristic in such a way that the intersection points lie on a
continuous tangent; the rounding range can be set as required. The following diagram shows
an example of a characteristic and illustrates how the associated machine data works.
The transition point is defined by the percentage for input (voltage) and output (volume flow).
Figure 5-16
Hydraulic Drive
System Manual, 04/2015, 6SL3097-4BA00-0BP1
Valve characteristic with transition point in zero, fine control and saturation ranges
Drive functions
5.5 Control voltage output
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