The XM-121A absolute shaft module measures turbine shaft vibratory motion relative to free space. The modular, open design of XM machine condition monitoring and protection technology allows users to expand the XM-121A system to include other modules or to link the device into a broader system. The XM-442 voted EODS relay module is the final piece in the Allen Bradley XM EODS. The XM-442 provides four high-power relays %%MDASSML%% three that serve as redundant shutdown relays and one that serves as the alarm relay. Redundant logic circuits allow the XM-442 module to operate correctly, even in the presence of a single internal circuit fault.