Hier werden die Unterschiede zwischen zwei Versionen angezeigt.
Beide Seiten der vorigen RevisionVorhergehende ÜberarbeitungNächste Überarbeitung | Vorhergehende Überarbeitung | ||
embedded_systems:ethercat:test_and_tune_rt [2018-12-14 13:59] – mgehrig2 | embedded_systems:ethercat:test_and_tune_rt [2023-04-11 11:12] (aktuell) – Urs Graf | ||
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'' | '' | ||
- | See [[embedded_systems: | + | If the master cannot guarantee a stable clock, the masterShift mode is recommended. |
+ | |||
+ | See [[embedded_systems: | ||
Zeile 26: | Zeile 28: | ||
==== Cyclictest ==== | ==== Cyclictest ==== | ||
The Cyclictest is a software that can be used to easily measure the maximum jitter of a system. | The Cyclictest is a software that can be used to easily measure the maximum jitter of a system. | ||
- | [[software: | + | [[software: |
=== 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 the following [[software: | ||
+ | |||
+ | * cpuidle.off=1 | ||
+ | * intel_idle.max_cstate=0 | ||
+ | |||