Siemens SINUMERIK 840D Description Of Functions page 83

02.99
 Siemens AG 2000. All rights reserved
SINUMERIK 840D/SIMODRIVE 611 digital Descr. of Functions HLA Module (FBHLA) – 04.00 Edition
0.100
Fig. 3-32 Timing of disturbance step change, integral branch of velocity controller deacti-
vated
Trace 1: Valve spool setpoint
Trace 2: Actual velocity value
90.000
Ampl.
[dB]
10.000
1.000
180.000
Phase
[degrees]
–180.000
1.000
Fig. 3-33 Oscillogram showing velocity controlled system v
Note: Phase crossover -90 degrees essentially characterizes the
cylinder natural frequency
t [ms]
log [Hz]
log [Hz]
act
3 Start-Up
3.11 Start-up functions
100.000
1000.000
1000.000
/Q
act
3-83