Many mechatronics designs rely on a real-time operating system such as ThreadX from Express Logic. This type of small RTOS requires less memory than other operating systems such as Windows, Linux, VxWorks, and QNX, for example. So it suits applications that can take advantage of a low-cost processor and a small amount of memory. But by choosing a smaller memory, designers might conclude they limit the code and applications their system can use. To address this problem, Express Logic can now incorporate “downloadable application modules” in ThreadX. That means a small computer system can dynamically receive additional instructions from local mass storage (SD flash card, USB memory stick, small hard drive, and so on) or via a network. Thus additional or larger applications can still run on a small computer and companies can upload new or revised code without worrying about running out of memory space for the target processor. For details about ThreadX with downloadable modules, please visit: http://rtos.com/products/threadx/downloadable_application_modules.
According to Express Logic, ThreadX modules are collections of application threads, not linked with the ThreadX kernel. Instead, modules are loaded into target memory and use ThreadX kernel services via an interface with a Module Manager. The ThreadX Module Manager–part of the ThreadX kernel–starts a module and handles all module requests for ThreadX application-programming interface (API) services. Although ThreadX has only one copy of the Module Manager, it does not limit the number of modules that can be loaded at the same time, nor does it limit the number of threads in any module. Express Logic licenses ThreadX with Downloadable Modules for a fee that starts at $US 17,500. The license includes full source code and does not require any royalty fee.
If you have an existing system going through an upgrade or plan to implement a mechatronics controller with an RTOS, ThreadX deserves a close look. For more information on ThreadX for a wide range of applications, visit: http://rtos.com/products/threadx/. –Jon Titus