Siemens SINAMICS S120 Function Manual page 440

Function modules
7.7 Closed-loop position control
Restrictions
● Position tracking cannot be activated for an encoder data set which is used in different
● If an encoder data set is used in one DDS as a motor encoder with position tracking and
● If position tracking is reset in one drive data set, it is also reset in all other drive data sets
● The maximum permissible movement of an axis in an inactive drive data sets is half the
The table below describes the changeover behavior on transition from one DDS to another.
A changeover is always executed by DDS0.
An overview of DDS changeover without position tracking load gear can be found in section
"Instructions for data set changeover" in Section "EPOS - referencing".
Table 7- 4 DDS changeover with load gear position tracking
DDS p0186 p0187
(MDS) (encoder_1)
0 0 EDS0
1 0 EDS0
2 0 EDS0
3 0 EDS0
438
drive data sets as encoder1 for different gears. If an attempt is still made to activate
position tracking, fault "F07555 Drive encoder: Configuration position tracking" will be
displayed with fault value 03 hex.
A check is generally performed to determine whether the load gear is the same in all DDS
in which the relevant encoder data set is used.
Load gear parameters p2504[D], p2505[D], p2720[D], p2721[D] and p2722[D] must be
identical in this case.
in another DDS as an external encoder, the position tracking starts from the beginning
again, i.e. it behaves in the same way as it would do after a POWER ON.
which contain this encoder data set.
encoder range (see p2722: tolerance window).
p0188 p0189
(encoder_2) (encoder_3)
EDS1 EDS2
EDS1 EDS2
EDS1 EDS2
EDS1 EDS2
Encoder Mechanical
for conditions
position
p2504/ p2505/
control
p2506/ p2503
p2502
encoder_1 xxx
encoder_1 xxx
encoder_1 yyy
encoder_2 xxx
Function Manual, (FH1), 01/2013, 6SL3097-4AB00-0BP3
Position Changeover
tracking response
Load gear
Activated -
Activated Changeover during
pulse inhibit or
operation has no
effect
Deactivated Encoder adjustment
and referencing bit
are reset. Position
tracking for EDS0 is
no longer calculated
and must be re-
adjusted when
switching back to
DDS0.
Activated Position tracking for
EDS0 is continued
and the referencing
bit is reset.
Drive functions
1)