Siemens SINAMICS S120 System Manual page 174

Drive functions
5.5 Control voltage output
● Valve characteristic with transition in the zero range
To calculate the inverse characteristic, a transition point is defined in the positive zero
range of the valve characteristic with p1833 and p1834 and in the negative zero range
with p1836 and p1837.
The positive and negative valve flows at the transition point in relation to the nominal flow
(p0202) are entered in p1833 and p1836 respectively.
The valve voltage at the transition point in relation to the nominal valve voltage (p0204) is
entered in p1834.
For factory setting "0" in p1834 there is no transition point in the positive zero range.
For factory setting "0" in p1834 there is no transition point in the negative zero range.
The rounding range is parameterized in p1835.
● Valve characteristic with transition point in the fine control range
To calculate the inverse characteristic, a transition point is defined in the positive
quadrant of the valve characteristic with p1839 and p1840 – and in the negative quadrant
with p1842 and p1843.
The positive and negative valve flow rates at the transition point in relation to the nominal
flow rate (p0208) are entered in p1839 and p1842 respectively.
The positive and negative valve voltages at the transition point in relation to the nominal
valve voltage (p0205) are entered in p1840 and p1843 respectively.
When the same values (defaults) are set in p1839 and p1840, the characteristic is linear
(without transition point in the zero range (default) and without saturation (default)).
This transition point data is preset from the valve data (p0205, p0206) using "Calculate
controller data". It can be changed later. The rounding range is not a valve data and is
therefore only preset to a default value. It can however be changed later by the user
(p1841). If necessary, a measurement can be taken to obtain a precise setting.
Note
A constant machining velocity of the drive directly at the transition point of the valve is not
recommended.
● Valve characteristic with transition point at the start of a saturation range
To calculate the inverse characteristic, the beginning of a saturation range with parabolic
rounding in the positive quadrant of the valve characteristic is defined in p1845 and
p1846 and in the negative quadrant with p1847 and p1848.
The positive and negative valve flow rates at the start of the saturation range in relation to
the nominal valve flow rate (p0208) are entered in p1845 and p1847 respectively.
The positive and negative valve voltages in relation to the nominal valve voltage (p0205)
are entered in p1846 and p1848 respectively.
The saturation range is compensated by a root characteristic such that the intersection
point lies on a continuous tangent and the characteristic ends at the point (100%, 100%).
For a standard value of 100% in p1845 and p1846 or p1847 and p1848 there is no
saturation range in the positive or negative quadrants.
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System Manual, 04/2015, 6SL3097-4BA00-0BP1
Hydraulic Drive