MEMs Based Wired Condition Monitoring Solution for Industry 4.0

This paper discusses a novel communication scheme for porting SPI output from MEMs accelerometers over long distance for condition-based monitoring (CbM). Common challenges in designing a wired physical layer for MEMs include EMC robustness and data integrity. However, when extending clock synchronised SPI over long cables, and combining power and data on the same twisted pair wires (phantom power), several additional challenges are presented. Challenges discussed in this paper include managing system time synchronisation, and filter design and simulation for shared power & data architectures. Filter design is especially important where the designer cannot add Manchester encoding to remove signal DC content. Passive Filter component selection is discussed with available communication design windows and experimental measurements over cabling. Temperature effects on system performance is measured, and EMC immunity is quantified. All concepts are verified on a wired CbM platform.