Description

The TRICONEX 4355X TCM (Tricon Main Processor) is a high-integrity, triple-modular redundant (TMR) central processing module designed for the Tricon™ safety instrumented system (SIS) platform by Schneider Electric (formerly part of Invensys). As the computational heart of Tricon v10 and v11 systems, the 4355X TCM delivers fault-tolerant control for mission-critical applications requiring SIL 3 compliance per IEC 61508/61511, including emergency shutdown (ESD), fire & gas (F&G), burner management (BMS), and turbomachinery protection.

Unlike conventional PLCs, the TRICONEX 4355X employs three independent microprocessor channels that execute identical logic simultaneously. A proprietary hardware-based voter continuously compares results across all three legs—masking faults in real time without interrupting control output. This architecture ensures zero single-point failures and allows online maintenance (hot-swap) during live operation. The 4355X TCM features enhanced processing speed, expanded memory (up to 32 MB application space), and support for fast I/O scan cycles (<10>

Technical Specifications

Main Features and Advantages

✅ True Fault Tolerance with Zero Downtime
The TRICONEX 4355X TCM’s TMR design ensures continuous operation even if one (or in some cases, two) processor channels fail. Faults are detected, isolated, and reported without triggering spurious trips—critical for processes where unplanned shutdowns cost millions per hour.

✅ High Performance for Fast Safety Responses
With sub-10 ms I/O scan capability and deterministic execution, the 4355X meets stringent timing requirements for compressor anti-surge, turbine overspeed, or reactor pressure relief systems where milliseconds determine safety outcomes.

✅ Seamless Migration & Backward Compatibility
The 4355X fits directly into existing Tricon chassis (e.g., 8310A, 8311A) and works with legacy analog/discrete I/O modules. This enables end-users to modernize aging SIS without rewiring field devices or re-engineering safety logic.

✅ Built-In Diagnostics & Cyber Security
Advanced self-tests run continuously at power-on and during operation. Firmware is digitally signed to prevent unauthorized modifications—supporting compliance with ISA/IEC 62443 cybersecurity standards in OT environments.

✅ Global Acceptance in Regulated Industries
Widely approved by classification societies (DNV, ABS, Lloyds) and mandated in many oil & gas projects, the 4355X TCM provides auditable proof of functional safety for regulatory submissions.

Application Field

The TRICONEX 4355X TCM is deployed wherever human life, environmental integrity, or asset protection depends on fail-safe automation:

• Oil & Gas: Offshore platform ESD, pipeline rupture detection, wellhead control

• Power Generation: Boiler furnace safeguarding, steam turbine trip systems, nuclear auxiliary safety

• Chemical & Petrochemical: Reactor temperature/pressure interlocks, batch process containment

• LNG & Hydrogen: Cryogenic pump protection, vapor recovery system shutdown

• Mining & Metals: Conveyor belt emergency stops, smelter off-gas monitoring

• Water/Wastewater: Chlorine injection safety cutoffs, high-level tank alarms

Related Products

• 4329 / 4328 TCM: Older Tricon main processors; 4355X is the recommended replacement

• 4351A / 4352A: Communication modules (Ethernet/IP, Modbus TCP) for connecting 4355X to DCS or asset management

• 3503E: 16-channel 4–20 mA analog input module (commonly used with 4355X)

• 3664E: 32-channel discrete output module with diagnostic feedback

• 8310A / 8311A: Tricon chassis that houses the 4355X TCM and I/O modules

• TriStation 1131: Engineering software for programming, simulation, and diagnostics of 4355X applications