Operating systems normally used for office applications are not suitable for real-time operations. As in all Unix systems, Linux scheduler is preemptive, only at user lever, that means that an high priority user process, when ready to be executed, can suspend a lower priority user process but not a kernel one. Not-preemptability of kernel processes is the greater obstacle for the execution of real time tasks. Real Time Linux uses the Linux Operating Systes as a normal proces executed by a small real time operating system. The main goal of this work is to exploit a RealTime Linux platform in controlling a robot arm.