Lenze PROFIBU PC-based Automation - Manual (Page 60)

Control technology | PROFIBUS communication manual
Defining the minimum cycle time of the PLC project
Calculating the minimum cycle time
60
L
DMS 2.2 EN 07/2011 TD17
9.3 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:
Example

Note!
For calculating the minimum cycle time, a safety factor of 1.5 is included.
T
min
> safety factor x ( T
Task utilisation
+ T
Correction
)
Configuration: Industrial PC (ATOM 1.6 GHz) with 3 axes
Access time determined
Result
Calculated correction value T
Correction
200 μs
(140 μs + 40 μs +(2 x 10 μs))
Value read from task configuration: T
Task utilisation
500 μs
Actual required computing time 700 μs
Minimum cycle time including a safety factor of 1.5 T
min
1050 μs
Actual cycle time 2000 μs