Maretron SIM100 Switch Indicator Module

The Maretron SIM100 Switch Indicator Module is a dedicated NMEA 2000 monitoring device designed to supervise switch closure sensors across marine safety, security, and vessel systems. This compact module continuously broadcasts real-time switch status data to your boat's NMEA 2000 network, providing centralized visibility of critical equipment states without requiring individual wiring runs to each monitoring station or display unit.

The SIM100 accepts input from a wide range of switch-closure devices, including safety detectors (smoke, heat, carbon monoxide, explosive vapor), security sensors (motion, vibration, glass break, door and porthole magnetic switches), and vessel monitoring equipment (bilge high-water alarms, valve open/closed status indicators). Each switch is monitored in real time, with status updates transmitted continuously across the NMEA 2000 backbone. This architecture eliminates the need for proprietary hardwiring and allows any connected display—chartplotter, instrument panel, or multifunction display—to access switch data simultaneously. The module's compact footprint (7 x 5 x 10 inches, 1.3 lbs) makes it suitable for installation in engine rooms, helm cabins, or other below-deck locations where space is limited.

Cruising sailboats, fishing vessels, and trawlers rely on centralized alarm monitoring to avoid missing critical warnings in rough conditions or during high operational tempo. The SIM100 consolidates multiple discrete alarms into a single NMEA 2000 data stream, reducing alert fatigue and ensuring operators can review all switch states from a single display interface. When integrated with a Maretron display system or compatible third-party NMEA 2000 instruments, the module provides audit trails and logged history of alarm events—valuable for maintenance scheduling and insurance documentation.

Maretron's SIM100 is built around the NMEA 2000 standard, the marine industry's open-architecture networking protocol. This ensures long-term compatibility with other marine electronics and reduces the risk of vendor lock-in common with older proprietary systems. Proper installation and configuration of switch inputs is essential; consult your Maretron documentation and electrical diagrams before connecting sensors.