Lenze EtherCAT control technology - Manual (Page 128)

Control technology | EtherCAT communication manual
Defining the minimum cycle time of the PLC project
Calculating the minimum cycle time
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DMS 3.1 EN 01/2011 TD17
10.3 Calculating the minimum cycle time
The minimum cycle time T
min
for a system results from the sum of the times detected
before, multiplied by the safety factor:
T
min
> Safety factor * ( T
Task utilisation
+ T
Correction
)
Example

Note!
The safety factor 1.5 is included in the calculation.
Configuration: System with Intel Celeron 1 GHz processor and six motion axes
Detected access time
Result
Calculated correction value T
Correction
160 μs (= 130 μs + 6 * 5 μs
Value read from task configuration: T
Task utilisation
500 μs
Actual required computing time 660 μs
Minimum cycle time including the safety factor 1.5 T
min
990 μs
Actual cycle time 1000 μs