TRICONEX 3721N 16-Channel Safety Digital Output Module for Tricon SIL 3 SIS

Product Description

The TRICONEX 3721N is a high-integrity Triple Modular Redundant (TMR) 16-channel digital output module, engineered by TRICONEX (Schneider Electric) for SIL 3 safety instrumented systems (SIS) in critical industrial environments. As a core safety signal execution component, this hot-swappable module (supplied as a TMR set of 3) is designed to drive discrete safety actuators (solenoid valves, alarm horns, trip relays) via 24 VDC sinking outputs with high noise immunity and channel-level diagnostics. It features channel-to-channel and channel-to-ground isolation, TMR majority voting, and seamless integration with Tricon/Tricon CX chassis—making it ideal for emergency shutdown (ESD), fire & gas (F&G), and process safety systems in oil & gas, chemical, petrochemical, and power generation industries.

Key Functions

The 3721N digital output module delivers fault-tolerant, TMR-voted discrete signal execution for safety-critical applications. Key functions include: 16 independent sinking digital output channels (24 VDC nominal); channel-to-channel and channel-to-ground isolation (2500 V AC optical isolation) to prevent ground loops and electrical noise interference; TMR majority voting (2-out-of-3) for output integrity; hot-swappable design for online maintenance without system shutdown; LED status indicators for module health, channel active status, and voting results; and compatibility with Tricon/Tricon CX main/expansion chassis.

Application Scenarios

The TRICONEX 3721N digital output module is deployed in safety-critical industrial applications requiring high-integrity discrete signal execution with SIL 3 compliance. In offshore oil & gas platforms and refineries, it drives ESD solenoid valves, fire alarm horns, and emergency isolation valves to trigger safety shutdowns. For chemical and petrochemical plants, it controls reactor trip relays, toxic gas mitigation system actuators, and emergency vent valves, ensuring coordinated safety actions and compliance with IEC 61508/61511 standards. In power generation facilities, it connects turbine/generator trip relays, breaker control circuits, and cooling system actuators to Tricon SIS, supporting regulatory compliance and operational reliability. The module is also used in mining, pharmaceutical, and water/wastewater treatment—all scenarios where secure, high-availability discrete signal execution is mandatory.

Technical Specifications