Product Overview

The 3361 is a high-integrity Digital Input (DI) module specifically engineered for the Tricon Triple Modular Redundant (TMR) safety system. This module provides 32 isolated input channels designed to interface with 24 VDC field contacts in Safety Instrumented Systems (SIS). By utilizing three independent processing paths, the module ensures that a single component failure does not compromise the safety function or cause a nuisance trip. Each input signal is voted upon at the hardware level, providing the extreme reliability required for SIL 3 rated applications. This module is the industry standard for monitoring critical process states where signal accuracy is the highest priority.

Core Technical Functionality

• Triple Modular Redundancy: Features three isolated internal legs that synchronize and vote on all incoming signals to ensure maximum fault tolerance.

• Input Isolation: Provides robust galvanic isolation between field circuitry and the system backplane to protect against electrical surges.

• Continuous Self-Diagnostics: Conducts comprehensive internal testing of the input circuitry to detect latent hardware faults without interrupting the process.

• High-Density Architecture: Supports 32 input points in a single chassis slot, optimizing cabinet space for large-scale deployments.

• Status Monitoring: Equipped with front-panel LED indicators for each channel, allowing technicians to verify field contact status at a glance.

Industrial Application Scenarios

The 3361 is predominantly utilized in high-risk sectors where a fail-safe response is mandatory:

• Oil & Gas: Monitors emergency shutdown (ESD) pushbuttons and fire detection sensors.

• Chemical Processing: Tracks the status of limit switches on safety-critical valves.

• Power Generation: Supports burner management system (BMS) interlocks and turbine trip signals.

Because the module can withstand harsh electromagnetic environments, it maintains consistent performance in proximity to high-capacity motor switchgear.

Technical Specifications