RTX (operating system)

Overview

Technical details

• Hardware abstraction layer extensionRTX relies on a Windows hardware abstraction layer extension to initialize the RTX-dedicated processors and to provide the real-time subsystem with high resolution timers. It also provides an interrupt isolation mechanism.
• Symmetric multiprocessingLike Windows, RTX is based on a symmetric multiprocessing architecture. Depending on the real-time needs, users can choose the number of processors to dedicate to RTX to run real-time processes. RTX can use up to 31 dedicated processors; RTX64 can use up to 63. Users can then scale real-time applications between the RTX dedicated processors.
• Interrupt managementRTX supports both line based and Message Signaled Interrupts. Interrupt service thread latencies are under 10 microseconds.
• Memory managementThe deterministic memory pool allocated for RTX is taken from the system non-paged pool memory. For example, under Windows 7, the amount of non-paged pool is: for 32-bit, 1 GB to 2 GB of the random-access memory depending on the configuration; for 64-bit, 75% up to a maximum of 128 GB.
• SchedulingOne scheduler is used across all real-time processors. It uses priority-driven and pre-emptive algorithms to ensure critical thread context switches. Priority promotion mechanisms are provided to avoid priority inversion. Yields to threads of higher priority occur with sub-microsecond timing.
• Windows interactionRTX provides separation from Windows. Windows processes cannot interfere with real-time applications. If Windows issues a STOP message or shutdown, real-time applications have the ability to continue running to shutdown safely. Communicating with Windows occurs via RTX providing common inter-process communication mechanisms between real-time processes and Windows processes. Synchronizing is done via events, mutexes and semaphores; data sharing via shared memory or socket communication.
• Real time application developmentRTX application development is done from Microsoft Visual Studio in C or C++ using a windows-like application programming interface. RTX executable are .rtss and DLLs are .rtdll.
• Network communicationThe RTX real-time TCP/IP stack supports TCP, UDP, and IP for IPv4 and IPv6. RTX drivers for standard network interface controllers are provided with the stack.