Setting The Sampling Times - Siemens Sinamics S120 Function Manual

Commissioning
6.6 Commissioning Safety Integrated functions
6.6.4

Setting the sampling times

Terminology
The software functions installed in the system are executed cyclically at different s ampling
t imes (p0115, p0799, p4099).
Safety functions are executed in the monitoring cycle (p9500) and the TM54F is executed
with the s ampling t ime displayed in r10015. This sampling time corresponds to the lowest
value of the communication sampling time entered in p10000[0..5]. For Basic Functions, the
cycle is displayed in r9780.
Communication via PROFIBUS is performed cyclically via the c ommunication cycle.
During the PROFIsafe scan cycle, the PROFIsafe telegrams issued by the master are
evaluated.
Rules
● The monitoring cycle (p9500) can be set between 500 μs to 25 ms.
Not e
S et ting an identical monitoring cycle
The monitoring cycle must be the same on all drives and the TM54F.
However, the calculation time required for the Extended Functions in the Control Unit
depends on the monitoring cycle, that is, shorter cycles extend the calculation time. The
availability of a specific monitoring cycle therefore depends on calculation time resources
of the Control Unit.
CPU time resources on the Control Unit are influenced primarily by the number of drives,
the number of drives with enabled Extended Functions, the connected DRIVE-CLiQ
components, the selected DRIVE-CLiQ topology, the use of a CBE20 and by the selected
technological functions. You can determine the number of axes that can be controlled
(closed loop) using the "SIZER" tool.
Not e
Inf luence of deactivated drives on the required CPU time
Please note that the deactivated drives also affect the required CPU time. In the case of
utilization limits being reached, it is sufficient to deactivate one drive. This drive must then
be deleted.
236
Function Manual, (FHS), 07/2016, 6SL3097-4AR00-0BP6
Safety Integrated