Windows NT and 2000 are designed as business operating systems. NT's success is prompting uses that extend beyond the initial purposes, including mission critical control, and applications requiring real-time determinism. Developers of real-time applications desire the benefits that come from using Windows, but require a focused real-time development and execution environment in keeping with traditional RTOS's performance and determinism. VenturCom’s RTX technology enables Windows NT and 2000 to elegantly address these needs.

RTX delivers the benefits of Windows plus:

• Allows high performance deterministic real-time and non-real-time processing within the same computer
• Enables Windows to handle control oriented applications
• Leverages industry standard development and debugging tools
• Leverages the pool of experienced Windows development engineers
• Provides a portability strategy between Windows NT and CE

RTX enables Windows NT to function as both a general-purpose operating system and a high-performance real-time operating system – at the same time, on the same computer. With RTX, Windows NT truly extends "across the enterprise" – from performing control operations on the factory floor to serving applications and data to the corporate enterprise.

RTX Features

• Develop and debug applications as standard Win32 applications or real-time processes with standard Microsoft tools

• Applications can start seconds into the boot cycle for quick recovery of control tasks

 RTX APIs (Application Programming Interface) provide a complete and powerful Win32-based programming interface designed to support all real-time applications and real-time device drivers. The RTX API consists of both Win32 functions specially selected to provide real-time performance, and other functions required for direct interfacing to hardware devices. Standard development tools, such as Microsoft Visual Studio and Visual C/C++, are used to develop RTX applications. The C and C++ languages are supported by RTX along with the C runtime library, various C++ libraries, and structured exception handling.

• Fixed Priority Scheduling

• Interprocess Communication and Synchronization

• Memory Management

• High Speed Clocks and Timers

• Port I/O

• Physical Memory Mapping

• Interrupt Management

Real-time Device Drivers are a common application for RTX. RTX provides a powerful model for building device drivers. Real-time device drivers utilize the same API and execute in the same context as real-time processes. This simplifies the development of interrupt handlers that are a frequent source of programming frustration. Interrupt handlers run in a full thread context and have the complete API available including floating point functions. Since interrupt handlers execute in thread context, thread priority determines the order of execution. High-priority application threads can pre-empt and execute before lower-priority interrupt handler threads. Utilizing a thread model for device drivers provides RTX developers with great flexibility in prioritizing and partitioning functionality between applications and device drivers, and provides flexible IPC mechanisms to connect applications and drivers.

 A Real-time Subsystem (RTSS)

The RTSS enables deterministic performance by utilizing the timer and interrupt management services of the real-time HAL necessary for provides the RTSS thread scheduler the fastest possible response to device interrupts and enables the lowest possible latency scheduling of RTSS threads. The RTSS environment is able to pre-empt NT at any time.

In addition, as an NT device driver, the RTSS can utilize the low-level memory management facilities available through the Windows NT executive for locked and contiguous memory allocation.

An additional feature of the RTSS is the compatibility and interoperability that it provides with Win32 -- the native Windows NT environment -- through a common API and support for shared real-time objects. By sharing a common API, the RTSS and Win32 environments can share real-time objects such as events, timers, memory, mutexes, and semaphores -- allowing communication and synchronization between the environments.

Finally, RTSS processes can continue executing after a Windows NT stop event, until an orderly shutdown, (the sequencing of critical hardware), is completed.

Typical NT Latencies

RTX Real-time Latencies

Packaging:

RTX SDK – Development Environment

RTX Runtime – Real-time Environment for Target Systems

RTX MP Runtime – Real-time Environment for Multiprocessor Target Systems