TRICONEX 3721 is a high-speed digital input (DI) module specifically designed for Tricon TMR (Triple Modular Redundancy) safety systems.

The Triconex system is a globally recognized high-integrity safety instrumented system (SIS) commonly used to control industrial processes critical to personnel, equipment, and environmental safety. The 3721 module reliably receives field-level digital signals.

Key Features

The core function of the Triconex 3721 module is the safe and reliable acquisition of field-level digital input signals:

High-Speed Digital Input (High-Speed DI): The module is designed to receive switch signals (ON/OFF states) from various field devices such as limit switches, pushbuttons, emergency stop buttons, flow/pressure switches, etc.

Triplicated Input Logic: Although the input points themselves are not triply redundant (typically single-point inputs), the module isolates these signals and transmits them to the Tricon system's **three independent processors (CPUs)** for voting (2-out-of-3 logic).

High Noise Immunity and Isolation: Provides optical isolation and high electromagnetic compatibility (EMC) to ensure signal integrity in harsh industrial environments.

Diagnostic Capabilities: The module features robust self-diagnostics, monitoring input signal loop conditions such as open circuits or short circuits, and reporting fault information to the main processor to enhance system safety and reliability.

High Density: Typically offers multiple channels (e.g., 32 channels) to efficiently integrate a large number of field signals.