Hier werden die Unterschiede zwischen zwei Versionen angezeigt.
Beide Seiten der vorigen RevisionVorhergehende ÜberarbeitungNächste Überarbeitung | Vorhergehende ÜberarbeitungNächste ÜberarbeitungBeide Seiten der Revision | ||
embedded_systems:ethercat:test_and_tune_rt [2018-12-14 13:59] – mgehrig2 | embedded_systems:ethercat:test_and_tune_rt [2018-12-18 09:49] – mgehrig2 | ||
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In such systems the OS provides the clock for the whole system.\\ | In such systems the OS provides the clock for the whole system.\\ | ||
'' | '' | ||
+ | |||
+ | If the master cannot guarantee a stable clock, the masterShift mode is recommended. | ||
See [[embedded_systems: | See [[embedded_systems: | ||
Zeile 29: | Zeile 31: | ||
=== Quick Measurement === | === Quick Measurement === | ||
'' | '' | ||
+ | |||
===== Improve RT performance ===== | ===== Improve RT performance ===== | ||
If the RT performance is not sufficient, the maximum jitter could be reduced with the following measures: | If the RT performance is not sufficient, the maximum jitter could be reduced with the following measures: | ||
+ | |||
+ | ==== Intel Scaling Governor ==== | ||
+ | Modern processors change the CPU frequency depending on the load to save power. | ||
+ | With an RT-OS this can lead to increased jitter. | ||
+ | If the frequency is fixed, the RT performance can be improved. | ||
+ | ATTENTION: If the CPU is fixed at a high temperature, | ||
+ | |||
+ | The frequency is controlled by the OS by a [[https:// | ||
+ | The '' | ||
+ | |||
+ | To get the current active governor:\\ | ||
+ | '' | ||
+ | |||
+ | To set the governor:\\ | ||
+ | '' | ||
+ | |||
+ | |||
+ | ==== Intel cstates ==== | ||
+ | Intel cstates indicate the power saving state of the processor. | ||
+ | These states can be locked with kernel parameters on the C0 state (no power saving measures). | ||
+ | |||
+ | {{: | ||
+ | |||
+ | Display current kernel parameters: | ||
+ | '' | ||
+ | |||
+ | Add kernel parameters: | ||
+ | - '' | ||
+ | - Add '' | ||
+ | * '' | ||
+ | - It should look like this: | ||
+ | * '' | ||
+ | - '' | ||
+ | - reboot the pc | ||