SMSA31 is a safety module designed to monitor and control safety circuits in safety gates equipped with magnetic switches and electromechanical safety limit switches operating in anti-valent mode. The module achieves Category 4, Performance Level e compliance according to EN ISO 13849-1, featuring dual safety channels that monitor NO and NC signals independently. It provides 3 NO safety outputs with electromechanical forcibly guided relays and 1 NC auxiliary output, supporting automatic, manual, or monitored manual start/reset operating modes. The compact 1-DIN design (17.5 × 110.8 × 121.1 mm) includes detachable screw terminals for flexible wiring, LED diagnostics for power supply and safety status, and operates on 24 Vdc ± 10% or 24 Vac -15%/+10% power supply. This module is ideal for machinery safety applications requiring reliable monitoring of single or multiple safety gates in cascade configurations, with TÜV approval and CE/cULus certifications.