Characteristic Information - Siemens SINAMICS S120 System Manual

4.17.9

Characteristic information

Measured characteristic
The measured characteristic represents the piston velocity depending on the valve control
voltage as percentage values. When measuring the characteristic, the piston moves
between the end points with increasing velocity and generates alternately a positive and
negative measured value at each movement.
The measured characteristic comprises maximum 512 measuring points.
A characteristic stored in the drive is specifically for a drive data set (DDS). The
measurement of the characteristic from which the characteristic stored in the drive is
determined, therefore always refers to the currently active drive data set.
Calculated characteristic
A simplified characteristic is stored in the drive, defined section-by-section from straight lines
and parabolic segments. These are configured using 16 parameters.
Figure 4-33
Starting at the zero point, the calculated characteristic comprises a short straight line, the
zero range, which is rounded through a parabola into a further straight line of the fine control
range. Also rounded off by a parabola, the fine control straight line transitions into the
saturation range. This starts with a straight line followed by a parabola along a continuous
tangent open to the bottom, which ends at point Q = 100%, U = 100%.
In order to display the measured and the calculated characteristics as congruent
characteristics, the piston velocity must be converted to percentage values with the aid of the
area adaptation and the controlled system gain.
Hydraulic Drive
System Manual, 04/2015, 6SL3097-4BA00-0BP1
Definition of the characteristic
Commissioning
4.17 Editing the valve characteristic
99