Siemens Sinamics S110 Function Manual page 327

Encoder types for single-encoder system
Incremental encoders or absolute encoders can be used for safe detection of the position
values on a drive.
Safe actual value acquisition relies on redundant evaluation of the incremental channels A/B
that supply sin/cos signals of 1 Vpp.
In single-encoder systems, encoders with photoelectric sampling only are permitted for safe
actual value acquisition. These optical encoders must supply sin/cos signals of 1 Vpp on the
incremental channels A/B.
The absolute position values can be transferred via the serial EnDat interface or an SSI
interface to the controller.
Note
Basic absolute encoders (e.g. ECI, EQI) that offer an EnDat interface with additional sin/cos
tracks, but operate according to an inductive measuring principle internally, are not permitted
for single-encoder systems.
Two read parameters are available for safe motion monitoring:
r9730: SI Motion maximum velocity
Displays the maximum velocity (load side) permissible due to the acquisition of actual values
for safe motion monitoring functions. The maximum velocity for actual value acquisition
depends on the actual value update clock cycle (p9311/p9511). Parameter p9311/p9511 can
be used to set the clock cycle of actual value acquisition for safe motion monitoring.
A slower clock cycle reduces the maximum permissible velocity, but also reduces the load
on the Control Unit for safe actual value acquisition.
The maximum permissible velocity which, if overshot, can trigger faults in safe actual value
acquisition, is displayed in parameter r9730.
With a default value of p9311/p9511 (0 ms), the isochronous PROFIBUS clock cycle is used
(or 1 ms in non-isochronous mode).
r9731: SI Motion safe position accuracy
Displays the maximum positioning accuracy (load side) that can be ensured due to the
acquisition of the actual value for the safe motion monitoring functions.
Both parameters r9730/r9731 depend on the relevant encoder type.
Overview of important parameters (see SINAMICS S110 List Manual)
● p9301.3 SI motion enable safety functions (Power Module), enable actual value
● p9501.3 SI motion enable safety functions (Control Unit), actual value synchronization
● p9302 SI motion axis type (Power Module)
● p9502 SI motion axis type (Control Unit)
● p9311 SI motion clock cycle actual value sensing (Power Module)
● p9511 SI Motion clock cycle actual value sensing (Control Unit)
Drive functions
Function Manual, 10/2008, 6SL3097-4AB10-0BP0
synchronization
Safety Integrated Functions
8.5 Extended Functions
327