Siemens SIMODRIVE 611 universal Function Manual page 604

6 Description of the Functions
6.14 Dynamic servo control (DSC, from SW 4.1)
n pre
Path inter–
polation
xset Xerr
T position
Offset
Master
Fig. 6-83 Principle of dynamic servo control; the speed setpoint is used for speed precontrol
Activation
Deactivating
Speed setpoint
value filter
6-604
Data transfer
Interpolator
deadtime
n pre
Data transfer
Interpolator
deadtime T position
Data
transfer
dead–
time
T position
Data transfer
deadtime TDP
Drive
If the prerequisites for DSC have been fulfilled, the function is activated
by transferring a value for KPC > 0 in the PROFIBUS telegram.
When DSC is activated, the position controller gain in the master
should be set again.
The DSC function is de–activated by setting KPC = 0. Then, only the
speed pre–control is effective.
Higher gain factors can be set using DSC. This is the reason that the
control loop can become unstable when DSC is disabled. Before disab-
ling DSC (e.g. for optional tests) the KV factor must be reduced in the
master.
When using DSC, a speed setpoint filter is no longer required to round–
off the speed setpoint stages.
When using the DSC function, it only makes sense to use speed set-
point filter 1 to support the position controller, e.g. to suppress reso-
nance effects.
SIMODRIVE 611 universal Description of Functions (FBU) – 04.05 Edition
Speed Speed
setpoint setpoint
filter 1 filter 2
KPC
T speed
Xact
E Siemens AG 2005 All Rights Reserved
01.99
Speed
controller