Real-time processing

RTOS or Real Time Operating Systems are designed for applications where responses to given inputs are needed immediately in real time as opposed to their general purpose counterparts that take a few seconds or even minutes for the same task. RTOSs also have the capability to handle multiple processes simultaneously within limited time. They are widely used in various mission-critical defense applications, such as air-traffic control, robotics and aerospace research. Most

RTOSs used by defense are typically embedded on a microchip. Here we look at some of them.

One widely used embedded OS is called VxWorks by a company called Wind River. It includes integrated networking capabilities and serves a complete development environment for both Windows and Unix hosts. The OS runs on more than 20 different processor families, some of which include PowerPC, Intel architecture, ARM and MIPS. Its major features include a fast, multitasking kernel with pre-emptive scheduling and fast interrupt response, and supports multiprocessor and efficient Unix—compatible memory management. It has far-reaching intertask communication and synchronization capabilities. It also has user interface, performance management and an I/O file system as well as source-level debugging capabilities. 

Applications of VxWorks



Some of the applications developed and deployed using VxWorks are found in Airborne Mission Computers, self-guided weaponry systems, navigation systems, missiles systems and also auto-pilot capabilities. It’s also used in radar and sonar applications, flight simulation, airline cabin-management systems, and satellite tracking systems. 

Let’s look at an Airborne Mission Computer that uses VxWorks for its operation. This computer uses advanced sensors to gather and analyze data for weather conditions and early warning command and control systems. One such computer, the AMC-300, designed and manufactured by BES Systems, is a P4B-pod miniature computer with a 233 MHz Pentium processor, 128 MB RAM, 48 MB RAM on chip, 10Base2 Ethernet, RS-422 or RS-232 serial interface, PCMCIA drive, and a SoundBlaster card with output impedance. It also has a Remote-terminal bus-monitor and GPS 1PPS processing. The AMC-300 runs on either Embedded VxWorks or Win CE with required Airborne applications and is used by F-15, F-16, A-4 and F-5 aircraft. AMC-300 assemblies are moisture-, dust- and vibration-resistant. It’s also damage-resistant to the effect of ambient temperature. 

Sanjay Majumder