Triconex 3625 TMR Digital 24 VDC Output Module

Product Overview

The 3625 (3625) is a high-availability Digital Output Module designed for the Triconex Triple Modular Redundancy (TMR) safety system. Featuring 32 commoned output points, this module provides the critical interface between the safety controller and final control elements such as solenoid valves, actuators, and motor starters. As a TMR-based component, the 3625 utilizes three independent internal channels to perform two-out-of-three (2oo3) voting at the hardware level, ensuring that a single component failure does not lead to a false trip or a failure to command. This level of fault tolerance makes it indispensable in high-stakes safety instrumented systems (SIS) within the oil and gas, petrochemical, and power generation sectors.

Technical Configuration

The 3625 is engineered for comprehensive diagnostics and fault-tolerant switching:

• TMR Architecture: Internal voting circuitry ensures that even if one of the three internal processors or output drivers fails, the module continues to function correctly without interrupting the process.

• Dual Operation Mode: Supports both Supervised and Non-Supervised configurations. In Supervised mode, the module monitors the field wiring for open and short circuits, even when the output is in the "Off" state.

• High-Density Output: Provides 32 digital output signals, commoned to simplify wiring in large-scale control cabinets.

• Hot-Swappable Design: Like all Triconex modules, the 3625 can be replaced online (Hot-Swapped) without shutting down the system, provided a redundant module is configured or a spare slot is available.

• On-Board Diagnostics: Includes localized LED signaling for module status, channel activity, and field-side fault detection.

Technical Specifications

Technical FAQs

What is the difference between Supervised and Non-Supervised modes on the 3625?In Supervised mode, the module injects a low-energy pulse to verify the integrity of the field loop (load and wiring). This allows the system to detect a "Line Break" or "Short Circuit" before the output is energized. Non-supervised mode is used for loads that are sensitive to testing pulses.

Does this module require an external Termination Panel?Yes. The 3625 must be connected to a specific Triconex External Termination Assembly (ETA) via an interface cable. The ETA provides the physical screw terminals for field wiring and any necessary fuses.

Can a single 3625 module support a SIL 3 safety function?Yes. Because the 3625 is internally redundant (TMR), a single module meets the requirements for SIL 3 safety loops, provided the entire safety loop (sensor to final element) is designed and calculated accordingly.

Engineering & Installation Guide

• Load Current Management: While the module is robust, ensure the total current draw of the 32 commoned outputs does not exceed the backplane or ETA power rating. For high-current solenoids, verify the "Inrush" current characteristics to avoid nuisance overcurrent trips.

• Supervision Pulse Sensitivity: If connecting to high-impedance loads or sensitive LED indicators, be aware that the supervision pulses may cause flickering. In such cases, disable supervision for those specific channels in the TriStation 1131 software.

• Module Seating: When inserting the 3625 into the chassis, ensure the top and bottom ejector levers are fully locked. A partial insertion can cause "I/O Communication" errors or intermittent voting faults between the Main Processors and the module.

• Shielding & Grounding: Always use the recommended Triconex shielded cables between the module rack and the ETA. Ensure the cable shield is grounded at the rack end to protect the 24 VDC output signals from electromagnetic interference (EMI).