The ABB 3BSE028586R1 is a high-integrity digital input module designed for safety-critical automation systems. Part of the S800 I/O architecture, this module offers 16 isolated digital inputs, each supporting 24 V DC signals. It is certified for SIL3 compliance, ensuring reliable operation in demanding industrial environments. The module features selectable filtering up to 127 ms, advanced diagnostics, and a Sequence of Events (SOE) function with 1 ms resolution, capable of recording up to 512 events. Each input channel includes current-limiting components, EMC protection, input status indicators, and optical isolation barriers. Designed for both single and redundant configurations, it requires specific termination units (TU810, TU812, TU814, TU818, TU830, TU833, TU838, TU842, TU843, TU852) for proper integration. The module operates within an input voltage range of 18 to 30 V DC, with an input current of 7 mA at 24 V DC. Its compact dimensions (45 mm width, 119 mm height, 102 mm depth) and lightweight design (0.15 kg) facilitate easy installation and integration into existing systems.