Realtime FAQ

FAQ1009: How to solve an interrupt conflict

There is an interrupt conflict when at least two devices, one from RTOS and one not, are sharing the same physical wire for signaling an interrupt. This way a non RTOS device could interrupt RTOS resulting in the loss of realtime capability.
A possible solution is
  • to assign the device without an interrupt. This requires specialized software and driver for the device on RTOS side like our Ethercat-LinkLayer. This solution does not work for any standard driver because they always expect the interrupt to be available.
  • to use Message-Signaled-Interrupts (MSI) instead of the legacy line interrupt. This must be supported by the device and driver but will avoid any conflict.
  • to put the device into another slot. Typically the interrupt lines are swapped between the slots so another line should be used.
  • to disable the conflicting non-RTOS device or also assign it to RTOS.
    In very rare cases host configuration allows the non-RTOS devices to be configured without an interrupt (like LPT for example).
  • to use a more recent or alternative version of the device supporting MSI.
If the conflict can't be solved this device can't be used for realtime on this platform due to the shared interrupt.

Last update on 2021-09-07 by Realtime Support Team.

FAQ1008: How to enable VT-x support only (without enabling VT-d)

Enabling VT-x without enabling VT-d is only useful for test purposes as no physical devices which need DMA support will work then. This may be usedful for example to determine if SMIs can be suppressed.

VT-x only can be enabled using the following config file entry:


Last update on 2021-03-15 by Realtime Support Team.

FAQ1007: How to get an update for the RTOS32Win, RT-Win and EC-Win(RTOS-32) products?

Request an update from acontis through the following site:

You will get the latest version then from acontis.

Check the On Time RTOS-32 version which is required for the update.

If necessary, update your On Time RTOS-32 version to this version. Do not use a different version, this is not supported by acontis.

Last update on 2020-12-17 by Realtime Support Team.

FAQ1006: How can I create my own setup?

Please checkout chapter 15 Appendix C - "Installation" of RtosVM-UserManual.pdf.

Last update on 2020-12-17 by Realtime Support Team.

FAQ1004: How can I generate an Error Report using the System Manager?

The following steps have to be executed to generate the error report:

  1. Start System Manager
  2. Load the Virtual Machine
    Start VMF
  3. Ignore the error message (e.g. cancel), do not stop the System Manager or shutdown Windows
  4. Generate the error report
    Generate Report

Last update on 2020-12-17 by Realtime Support Team.

FAQ1003: How can I get a virtual dongle to unlock my target?

Please checkout the following document RtosVM-UserManual-Licensing.pdf.

Last update on 2020-12-17 by Realtime Support Team.

FAQ1002: Can I use hyperthreading?

It can be enabled, but it is not recommended as the jitter will be significant higher and real-time behavior in most cases is not acceptable.

Last update on 2020-12-17 by Realtime Support Team.

FAQ1001: How can I determine, if my hardware is capable to run Real-time applications?

Please checkout our PC-Hardware and Real-time Optimization section.

Last update on 2020-12-17 by Realtime Support Team.

FAQ1000: Error 0x0022270B - Timer frequency measurement delay limit reached

The measuring periods to determine the timer input frequency varied above a minimum.

In case of problems regarding timer period (e.g. clock drift between master and slaves) this message indicates a possible reason. It can be ignored in other cases.

The message can be disabled using the following config file entry:


Disabling the message as no negative side effects.

Last update on 2021-03-15 by Realtime Support Team.

FAQ1202: How can I automatically start an application with command line parameters

Open the user configuration file and add 2 keys "Executable" and "Parameter".
"Executable" defines the path to the application that shall be started, "Parameter" will be used a the application's commandline parameter.
Here is an example of how to start the command "find / -iname rtos*" when Linux is booted,
"Parameter"="/ -iname rtos*"

Last update on 2021-02-17 by Realtime Support Team.

FAQ1201: How can I achieve better real-time performance

  1. Starting with LxWin 7.1.1 you can use rtos_nanosleep to introduce a guard band around the timer interrupt. Within this guard band no additional timer interrupts will be generated.
    Example Code Snippet here.
  2. Change the communication mechansim from interrupt mode to polling mode. This will avoid critical code being interrupted by Windows/Linux communication activities. Caveat: Windows/Linux communication performance may be reduced.
    Add the following configuration settings:
        "CommInterruptMode"=dword:0         ; Mode: 0=polling, 1=interrupt
        "PollingPeriodMs"=dword:1                  ; Mode: 0=interrupt, 1 and more for polling


Last update on 2021-02-17 by Realtime Support Team.

FAQ1200: LxWin: How to start a script automatically

Please follow these steps to run a script that is started along with Linux.

  1. Create a script file inside workspace\RtFiles folder.
  2. The script can contain Linux shell commands or call applications.. You can also call other scripts.
  3. Add a new [Rtos\Autostart\1] key into the configuration and assign the script name to the "Executable" parameter.

See also the chapter “5.5 Access Windows file system using Samba” in the “LxWin Product Manuel”, here you can find an example of how to start a script.

Last update on 2021-02-16 by Realtime Support Team.