Configuring the Real-time Subsystem

You can use RTX64 Control Panel to configure default settings for the Real-time Subsystem, including internal system behavior, memory management, monitoring, exception handling, power management, remote debugging, and real-time application output.

The Configure the RTSS Subsystem page contains the following options:

Option	Name	Description
	Change internal system behavior	Change how and when the RTX64 subsystem is started Change how frequently the internal system timers are triggered Change how the subsystem scheduler behaves Change the behavior thread termination Change how the subsystem handles priority inversion
	Manage memory	Set the default memory allocation behavior.
	Change monitoring settings	Configure the amount of memory dedicated to monitoring Automatically start a monitoring session on subsystem start Specify which events to monitor and the directory to save logs Specify the maximum log size and whether to stop monitoring or discard the oldest events when the limit is reached
	Configure watchdog timer settings	Choose whether to enable the RTSS Watchdog timer to observe and limit runaway threads
	Configure exception support	Choose how the Subsystem handles a faulting process Select how the Subsystem behaves when handling exceptions
	Configure power management settings	Change how some power management features are handled. This may minimize the effects that Windows power management features have on RTX64.
	Configure the search path	Configure a search path to allow RTX64 to look in specific directories when you attempt to load a RTSS application or RTDLL.
	Configure real-time application output	Configure the display and logging of real-time application output.
	Configure remote debugging	Configure the remote debugging connection. NOTE: The RTX64 Remote Debugger is an optional Runtime feature. These settings will only appear in the Control Panel when the RTX64 Remote Debugger feature is installed.

to open the control panel:

In the Start menu, navigate to RTX64 <Version> Runtime and click RTX64 Control Panel.

NOTE: In some instances, you may need to stop the Subsystem before you can modify a configuration setting.

Starting and Stopping the Subsystem

To start/stop the Subsystem from the Control Panel:

You can start and stop the RTSS Subsystem and associated components directly from the information panel on the right side of the Control Panel Home page.

To start the Subsystem, click the Start icon.

Note that this also starts the Network Abstraction Layer (NAL), if it is configured to start with the Subsystem, and the TCP/IP Stack, if the Stack is licensed and configured to start with the NAL.

To stop the subsystem, click the Stop icon.

For more information, see Starting and Stopping Components in the RTX64 Control Panel.

Changing the HAL Timer Period of the Subsystem

The RTX64 HAL Timer is the primary timer that the RTX64 Subsystem uses for all internal synchronization, timers and wait functionality. The default value for the subsystem HAL Timer Period is 100 microseconds. This value can be as low as 1 microsecond or as large as 1,000 microseconds.

This value can have an impact on the responsiveness of your subsystems and applications. Application timers can only have periods as small as the subsystem's HAL timer period or a multiple of it. For example, if the HAL timer period is 50 you can create a timer with a period of 50, 100, 200, but not of 130. A value of 130 would be rounded up to 150.

You can change the HAL Timer Period in the RTX64 Control Panel under Configure the RTSS Subsystem > Change internal system behavior.

NOTE: Use caution when setting the HAL timer period below 20 microseconds. If the HAL timer period is set too low, it can inversely impact performance or cause your system to hang. Fully test the timer period you set with your real-time application on all systems on which you will deploy to verify that the hardware can accomplish the compilations required in the period set.

Gathering Configuration Information

Sometimes it is useful to gather information about your current system state. You can use RTX64 Analyzer, accessible from the Control Panel, to generate a text file containing your current RTX64 configuration. You can then review the output file to evaluate system status and identify potential system inefficiencies or other problem areas.

RTX64 Analyzer can retrieve operating system information, RTX64 installation information, Visual Studio information, boot.ini/bcdedit information, processor information, BIOS information, memory information and plug-and-play device information. It can optionally be used to gather system latency information.

Exercise: Changing the available system memory

It is good practice to periodically compare the amount of available system memory in the RTX64 Control Panel with the actual amount in the Windows Task Manager. In this exercise, we will update the Available System Memory setting based on the actual Windows amount.

to update the available system memory:

Open the Control Panel.
Click Configure the RTSS Subsystem > Manage Memory.
Note the amount of system memory available to RTX64. The default value is based on the amount of available memory detected by the RTX64 installer.
You can view the current amount of available system memory in the Windows Task Manager under Performance > Memory.
To change the amount of available system memory, note the Available value in the Windows Task Manager and enter a value lower than it in the Available system memory text field.