Siemens Sinamics S120 Function Manual page 123

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 6,106,116,118,138 or free
telegrams.
For optimum control in the DSC mode, the same encoder(s) (encoder 2 and/or encoder 3)
must be selected for the control (master) and the drive via parameter p1192 "DSC encoder
selection".
Since the motor encoder (encoder 1) 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
Parameter r1407 indicates which DSC closed-loop control structure is active, e.g.
r1407.20 = 1 means "DSC with Spline on".
Preconditions for the indication:
● p1190 and p1191 must be connected to a signal source with a value of > 0
● 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
Function diagrams (see SINAMICS S120/S150 List Manual)
● 2420 PROFIdrive - standard telegrams and process data
● 2422 PROFIdrive - Manufacturer-specific telegrams and process data 1
● 2423 PROFIdrive - Manufacturer-specific telegrams and process data 2
● 2424 PROFIdrive - Manufacturer-specific/free telegrams and process data
● 3090 Dynamic Servo Control (DSC)
● 5020 Speed setpoint filter and speed pre-control
● 5030 Reference model
Drive functions
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
(DSC structure activated).
transmitted to p1191.
Servo control
3.15 Dynamic Servo Control (DSC)
121