Free Cycle Mode; Cycle Time For The Free Cycle Of Sm 335 - Siemens SIMATIC S7-300 Manual

Properties and technical data of SM 335
1.6 Operating modes of SM 335
1.6.1

Free cycle mode

Cycle
The term "cycle" in the context of SM 335 refers to the successive measurement of the value
at all analog inputs. The measuring cycle restarts after all inputs were read. This cycle has
nothing in common with cyclic program execution on a SIMATIC S7 CPU.
Free cycle
Within the free cycle of SM 335 all analog I/O of SM 335 are processed successively and
without interruption. Conversion of the first analog input restarts immediately after all inputs
and outputs have been processed.
To activate the free cycle, set up a cycle time of 0.5 ms for SM 335 in HW Config.
The following figure shows the structure of the cycle time for the free cycle.
Figure 1-3
22

Cycle time for the free cycle of SM 335

SM 335 - High-speed analog mixed module for SIMATIC S7-300
Manual, 02/2009, A5E02409063-01