TRICONEX 3400 Series Modules | 3401 Digital Output Module

Technical Dossier

Product Details And Specifications

TRICONEX 3400 Series: Comprehensive Module Range and Technical Overview

The TRICONEX 3400 Series is a core component family within the Triconex Triple Modular Redundant (TMR) Safety Instrumented System (SIS) platform, developed by Invensys (now Schneider Electric). This series is deployed across the most demanding process safety environments globally, including petroleum refining, LNG terminals, nuclear power generation, offshore platforms, and large-scale chemical manufacturing. The 3400 Series occupies the digital output tier of the TMR architecture, providing fault-tolerant discrete control signals to final control elements such as solenoid valves, motor starters, and relay-driven actuators. Its installed base spans hundreds of facilities across North America, the Middle East, Europe, and Asia-Pacific, making it one of the most widely maintained legacy SIS module families in the industrial automation sector.

The Evolution of 3400 Series Architecture

The TRICONEX 3400 Series was introduced as part of the second-generation Tricon platform, designed to address the limitations of earlier relay-based safety systems. The architecture is built on the TMR principle: three independent processing legs (A, B, C) each execute the same logic simultaneously, with a voter circuit determining the output state based on a 2-out-of-3 consensus. This design achieves SIL 3 certification per IEC 61511 and IEC 61508 without requiring redundant power supplies or external voting hardware.

Early 3400 Series modules used parallel backplane communication with fixed-address slot assignments. Later revisions introduced enhanced diagnostics, improved MTBF ratings, and compatibility with the Tricon v9 and v10 firmware environments. The transition from Tricon to Trident and TriGP platforms introduced incompatible backplane pinouts, meaning 3400 Series modules are not interchangeable with 3700 or 3800 Series components. Sites running Tricon v9.x or earlier firmware must source original 3400 Series hardware; firmware upgrades to v10+ may require concurrent module qualification testing. As of 2026, the 3400 Series is in the mature/end-of-life phase. Schneider Electric has transitioned active development to the Tricon CX platform. However, the installed base remains extensive, and OEM spare parts support has been formally extended through authorized lifecycle programs and third-party MRO suppliers.

3400 Series Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified module inventory within the TRICONEX 3400 Series. Each module is classified by functional category and is compatible with the Tricon TMR chassis unless otherwise noted.

Digital Output Modules

• 3401: 32-channel 24VDC digital output module, TMR voted, solid-state outputs, SIL 3 rated
• 3403: 16-channel relay output module, dry contact, 120VAC/24VDC rated, TMR architecture
• 3405: 32-channel 120VAC digital output module, optically isolated, high-current capacity
• 3407: 16-channel high-density relay output, Form C contacts, for motor starter applications
• 3409: 32-channel 24VDC DO module with enhanced diagnostics and short-circuit protection

Digital Input Modules

• 3501: 32-channel 24VDC digital input module, TMR voted, field-powered, SIL 3
• 3503: 32-channel 120VAC digital input module, optically isolated, high-noise immunity
• 3505: 16-channel digital input, dry contact, for pushbutton and switch interfaces
• 3507: 32-channel 48VDC digital input module, extended voltage range for legacy field devices

Analog Input Modules

• 3601: 16-channel 4–20mA analog input module, TMR voted, HART-transparent
• 3603: 8-channel thermocouple input module, multi-type (J, K, T, E, R, S, B), cold junction compensated
• 3604: 8-channel RTD input module, PT100/PT1000, 3-wire and 4-wire configurations
• 3607: 16-channel analog input, 0–5V / 1–5V / 0–10V configurable, for legacy transmitters

Analog Output Modules

• 3703: 8-channel 4–20mA analog output module, TMR voted, loop-powered, SIL 2 rated
• 3706: 4-channel analog output, 0–20mA, for valve positioner and speed controller interfaces

Communication & Processor Modules

• 3008: Main Processor Module (MP), Tricon v9/v10 compatible, dual-ported Ethernet, TriStation interface
• 3009: Enhanced Main Processor Module, extended memory, faster scan cycle, v10.x firmware
• 3201: Communication Module (CM), Modbus RTU/TCP, DH+, and proprietary Tricon peer-to-peer
• 3301: Termination Panel interface module, field wiring marshalling for 3400/3500 Series I/O

Sourcing Hard-to-Find & Obsolete 3400 Series Parts

The TRICONEX 3400 Series entered end-of-active-production status, with OEM new-build availability increasingly constrained. DriveKNMS maintains a dedicated inventory program for 3400 Series modules, sourced through decommissioned plant asset recovery, authorized distributor overstock, and certified refurbishment channels. All units are subject to pre-shipment functional verification against original TRICONEX factory test specifications.

DriveKNMS provides lifecycle extension support for the following scenarios: emergency breakdown replacement with same-day dispatch capability; planned turnaround (TAR) kitting for scheduled shutdowns; long-term spares agreements (LTSA) for facilities committed to maintaining Tricon TMR systems beyond OEM support windows; and cross-reference advisory for sites evaluating migration from 3400 Series to Tricon CX or third-party SIS platforms.

Quality Control for the 3400 Series Range

The TRICONEX 3400 Series presents specific quality verification challenges due to its TMR backplane architecture and voted I/O bus. DriveKNMS applies a structured test protocol for all 3400 Series modules prior to shipment:

• Backplane continuity verification: All edge connector pins are tested for continuity and impedance against reference values derived from OEM documentation. Bent, corroded, or intermittent pins are cause for rejection.
• TMR leg isolation test: Each of the three processing legs (A, B, C) is independently powered and verified for correct logic response. Cross-leg leakage is measured and must fall within OEM-specified limits.
• Output channel functional test: For DO modules including the 3401, each of the 32 output channels is individually energized and de-energized under resistive load. Solid-state output leakage current is measured at de-energized state.
• Analog accuracy calibration: AI and AO modules are calibrated against a traceable reference standard. Zero, span, and linearity are verified across the full input/output range.
• Firmware revision logging: Processor and communication modules are powered and firmware version is recorded. Compatibility with target Tricon system version is confirmed before dispatch.
• Thermal burn-in: Selected modules undergo 48-hour powered burn-in at elevated ambient temperature to screen for early-life component failures.