A study on universal serial bus latency in a real-time control system

In real-time operation of a computer system, the programs for the processing of input data are constantly operational so that the results will be available within predetermined periods of time. Universal Serial Bus has become an industry standard for attaching peripheral devices to the computer. This paper presents an overview of USB, measures the latencies caused by USB and USB hub and compares their latencies to determine whether USB hub adds overhead to USB. Experimental evaluation shows that USB is a good interface for soft real-time systems that can tolerate delays in the order of few milliseconds. It also provides insight needed for building real-time architectures that depend on USB to collect sensor data.