From 25ca7a263c7dbb7c84b2e1093f1c8c929d36be36 Mon Sep 17 00:00:00 2001 From: tbeu Date: Sun, 15 Mar 2015 21:10:34 +0100 Subject: [PATCH] Fix typos --- Modelica_DeviceDrivers/Blocks/OperatingSystem.mo | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Modelica_DeviceDrivers/Blocks/OperatingSystem.mo b/Modelica_DeviceDrivers/Blocks/OperatingSystem.mo index 869e2095..a1458366 100644 --- a/Modelica_DeviceDrivers/Blocks/OperatingSystem.mo +++ b/Modelica_DeviceDrivers/Blocks/OperatingSystem.mo @@ -48,9 +48,9 @@ package OperatingSystem
  • High Priority
  • Real-Time
    • -

    Note that the provided level of real-time synchronization is "soft", meaning that there are no guarantees that dead lines are met or that latencies are restricted to a predictable (low) maximum. This is often enough to satisfy requirements for interactive simulations and can be compared to the real-time experience provided by computer games. However, applications requiring "hard" real-time synchronization (e.g. HIL simulations) are not satisfied!

    +

    Note that the provided level of real-time synchronization is "soft", meaning that there are no guarantees that deadlines are met or that latencies are restricted to a predictable (low) maximum. This is often enough to satisfy requirements for interactive simulations and can be compared to the real-time experience provided by computer games. However, applications requiring "hard" real-time synchronization (e.g. HIL simulations) are not satisfied!

    Using the "High Priority" and "Real-Time" priorities in Linux will usually require "root" privileges for the simulation process. Using the "Real-Time" priority in Linux with a low-latency kernel as provided by the PREEMPT_RT patch will even provide limited (however, implementation specific limitations given below still apply) "hard" real-time capabilities (see e.g., https://www.osadl.org/Realtime-Linux.projects-realtime-linux.0.html).

    -

    IMPORTANT: This real-time synchronization is a hack. Don't rely on it in any (safety) relevant applications there precise timing is mandatory!

    +

    IMPORTANT: This real-time synchronization is a hack. Don't rely on it in any (safety) relevant applications where precise timing is mandatory!

    Implementation Notes

    The block introduces an equation with a call to an external C-function that takes the current simulation time as an argument. Within the C-function the simulation time is compared to the operating system real-time clock and execution of the thread is halted until simulation time == real-time. This equation will be added to the other model equations and sorted according to the (tool dependent) sorting algorithm. Therefore, no prediction can be made when, within the simulation cycle, the real-time synchronization function is called (e.g., it might be before, or after (external) inputs are read from a device or (external) outputs are written to a device).

    Final Remark