Siemens SINAMICS S120 System Manual page 93

Automatic tuning
You can perform the automatic tuning with the "Tune valve characteristic" softkey. Through a
limited number of iteration increments, the automatic tuning determines the position of the
transition points and the gradient of the straight lines so that the sum of the deviations
between the individual points of the tuned characteristic is as small as possible to the
measured characteristic. To obtain information on the set characteristic, press the
"Characteristic information" softkey.
The positive and negative velocity limits are also calculated during the automatic tuning.
They are only displayed in the dialog and cannot be changed.
The result of the automatic tuning depends on the characteristic set in the drive. If you
change the curve points manually and then press the "Tune valve characteristic" softkey, the
automatic tuning returns a different tuning result.
In an incomplete measurement, the controlled system gain and the area adaptation are
determined through extrapolation of the measured values. An incomplete measurement
characteristic must be extrapolated if, when the hydraulic drive operates, the complete
velocity range is to be used, although this was not able to be passed through when
measuring the valve characteristic. The control system gain is the conversion factor between
the control voltage and the piston velocity Q
The area adaptation is used to compensate the different piston areas of an asymmetric
differential cylinder. For the same volume flow (valve control voltage), this results in different
piston velocities in the positive and negative direction.
Performing manual tuning
Perform the tuning of the valve characteristic as follows:
● Use the LEFT, RIGHT, DOWN and UP cursor keys to select the parameter that you want
to change. The selected parameter is highlighted in orange in the value field.
● Enter the value with the numeric keypad.
● Press the ENTER key to update the graphic display of the characteristic.
● Use the "Accept" softkey to close the tuning of the characteristic. The measured values
as well as the measurement parameters and valve characteristic parameters are stored in
an XML file.
Hydraulic Drive
System Manual, 04/2015, 6SL3097-4BA00-0BP1
4.17 Editing the valve characteristic
at U = 100 %.
max
Commissioning
93