Siemens SINAMICS S120 Function Manual page 108

Servo control
3.15 Dynamic Servo Control (DSC)
Speed setpoint filter
A speed setpoint filter to smoothen the speed setpoint steps is no longer required when DSC
is active.
When using the "DSC" function, it only makes sense to use speed setpoint filter 1 to support
the position controller, e.g. to suppress resonance effects.
External encoder systems (except motor encoder)
If, with DSC active, an external encoder is to be used, this requires the selection of a
telegram with additional encoder actual values: Telegram 06,106,116 or free telegrams.
For optimum control in DSC mode, the same encoders must be used for the controller
(Master) and the drive via the parameter p1192 "DSC encoder selection".
Since the motor encoder is no longer used in this case, the adaptation factor for the
conversion of the selected encoder system into the motor encoder system is determined
using parameter p1193 "DCS encoder adaptation factor". The factor represents the ratio of
the pulse difference between the motor encoder and the used encoder for the same
reference distance.
The effect of the parameters p1192 and p1193 is illustrated in function diagram 3090.
Diagnostics
Via the parameter r1407.4 = 1 it can be indicated whether the speed setpoint of DSC is
used.
Preconditions for the indication:
● p1190 and p1191 must be connected to a signal source with a value of > 0
● OFF1, OFF3 und HALT2 must not be active.
● The motor data identification must not be active.
● Master control must not be active.
The "DSC" function cannot be active under the following conditions:
● Isochronous mode has not been selected (r2054 not equal to 4)
● PROFIBUS is not isochronous (r2064[0] not equal to 1)
● On the control side, DSC is not active, which causes the value of KPC =0 to be
Function diagrams (see SINAMICS S List Manual)
● 2420 PROFIdrive standard telegrams and process data
● 2422 Vendor-specific telegrams and process data
● 3090 Dynamic Servo Control (DSC)
● 5020 Speed setpoint filter and speed pre-control
● 5030 Reference model
108
(DSC structure activated).
transmitted to p1191.
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4
Drive Functions