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Table of Contents > QUARC > User's Guide > QUARC Targets > Specific Targets

QUARC QNX x86 Target

Industrial applications require an industrial-strength real-time operating system. That's why QUARC supports the popular QNX hard real-time operating system, which is one of the most widely used platforms in real-time systems. More specifically, the latest QNX Neutrino RTOS (Real-Time Operating System) can be used as a QUARC target. The processor families supported by this operating system include ARM, MIPS, PowerPC, SH-4 and x86. QUARC currently supports the x86 platform only, but watch the QUARC website for the latest support information. This section provides a general description of the QNX target in addition to limitations and requirements for this target type. Please use the following list to refer to each topic:

Beta

This target is currently a beta version. If you are using this target, we would appreciate any feedback at tech@quanser.com.

Description

The QNX target is a hard real-time system. The operating system is explicitly designed to ensure that deadlines, such as sampling instants, are met. Hard real-time operating systems provide a robust, stable platform for real-time control applications that minimize jitter and interrupt latencies.

In addition, the QNX Neutrino RTOS is a micro-kernel based OS, meaning that drivers and other components that are part of the kernel in other operating systems, are instead implemented as applications. This architecture results in a very fast kernel, with the flexibility to load and unload drivers at any time, making it possible to upgrade drivers without shutting down the system. This architecture also allows users to simply turn off any functionality they do not require without having to modify the OS itself. These properties, combined with QNX Neutrino's fast interrupt latencies and priority-based preemptive scheduler, make QNX a suitable platform for embedded and real-time applications.

Please keep in mind that using QUARC with a QNX target still requires a Windows host. Details on this requirement are given in the Requirements section of this page.

Limitations

Warning There is a limit on the fastest sampling time that may be set for a model using the QUARC system timebase on a QNX target. This limit is 10 microseconds, implying a maximum allowable sampling frequency of 100 KHz. In practice, limits in CPU speed and hardware bottlenecks prevent such fast sample rates from being achieved in general. Hardware-based timers may also be used. Refer to the HIL Timebase Blocks block category for more information on the QUARC blocks that can be used for hardware-based sampling times.

Requirements

As mentioned earlier on this page, running real-time code on a QNX target still requires a remote Windows host to be present. This is required since the real-time code to be run on the QNX target first needs to be generated on a Windows system with MATLAB, Simulink and QUARC installed. In addition, to build code for QNX targets the "Momentics X86 Cross Hosted Development Tools for Windows Host Environment" compiler is also required and should be installed on the Windows host. Be sure to exit any running instances of MATLAB prior to installing Momentics. Other software/hardware requirements for the QUARC QNX target are discussed in the QUARC Installation Guide supplied with the QUARC installation CD. Please note that even though QUARC must be installed on the Windows host, it is still necessary to install QUARC on the QNX target. The QUARC QNX installer must be used to install QUARC on the QNX target since the QUARC Target Manager must be present where the real-time code is running.

Please note that if your only intended target is QNX, the QUARC Windows target is not required and you can select not to install that component when installing QUARC. However the QUARC Simulink Development Environment component is required to generate code from your Simulink models.

 

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