Siemens SINUMERIK 840D Description Of Functions page 241

02.99
Hysteresis,
response
sensitivity, range
of inversion
 Siemens AG 2000. All rights reserved
SINUMERIK 840D/SIMODRIVE 611 digital Descr. of Functions HLA Module (FBHLA) – 04.00 Edition
These three terms express similar characteristics.
The term "Hysteresis" refers to the greatest difference in the input signal for
identical outputs signals on traversal of a full signal range.
On a servo solenoid valve, the hysteresis is caused by
S
mechanical friction,
S
magnetic hysteresis of electromagnetic signal transducer and
S
the play between transmission elements.
The position control corrects the hysteresis.
The hysteresis on Bosch closed-loop proportional values is less than 0.2 % and
is compensated for in the closed control loop.
The terms "Response sensitivity" and "Range of inversion" refer to the signal
level required to set a valve in motion again after it has stopped. The values of
these characteristics correspond to about half the hysteresis.
To overcome residual hysteresis or initial valve friction, a friction compensation
function can be activated in the HLA module.
Hysteresis
Response sensitivity
Range of inversion
Fig. A-13 Hysteresis, response sensitivity and range of inversion of servo solenoid valve
A.1 Servo solenoid valves
Q
U
Q
U
Q
U
A Hydraulics
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