Siemens SINAMICS S120 Function Manual page 172

Servo control
4.16 Dynamic Servo Control (DSC)
If the encoder for the position actual value generation in the control and the encoder selected
for DSC differ regarding their pulse numbers and/or fine resolution, then this must be taken
into account in p1193. The factor represents the ratio of the pulse difference between the
encoders used for the same distance reference. Further, it should be noted that for different
encoders there are no dead times regarding their position actual value sensing (for example
as is the case for EnDat encoders and SSI encoders), as this will otherwise lead to
undesirable behavior.
The effect of the parameters p1192 and p1193 is illustrated in function diagram 3090.
Wind-up effect
If the drive reaches its torque limits when in the DSC mode, e.g. because of excessively fast
setpoint inputs, then positioning motion can be overshot. With this so-called wind-up effect,
the drive overshoots the specified target, the controller enters a specific correction, the drive
reverses, overshoots the target again, etc. In order to avoid this behavior, the drive limits the
position controller to values that the drive can always reliably maintain depending on the
acceleration capability. Set p1400.17 = 1 to activate dynamic setpoint limiting in the DSC
mode. In this case, the total weight (m
weight p0341, p0342 and p1498 possibly using the mot ID). If the limiting responds, then this
is indicated in r1407.19. On this topic, also observe the description of parameter p1400.17
and function diagram 3090.
Diagnostics
Parameter r1407 indicates which DSC closed-loop control structure is active, e.g.
r1407.20 = 1 means "DSC with Spline on".
Requirements for the display:
● p1190 and p1191 must be connected to a signal source with a value of > 0
(DSC structure activated).
● OFF1, OFF3 and STOP2 must not be active.
● The motor data identification must not be active.
● Master control must not be active.
The following conditions can mean that although the bit is set, the DSC function is not active:
● Isochronous mode has not been selected (r2054 ≠ 4).
● PROFIBUS is not isochronous (r2064[0] ≠ 1).
● On the control side, DSC is not active, which causes the value of KPC = 0 to be
transferred to p1191.
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) must be precisely parameterized (determine the
tot
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Drive functions