TRICONEX 3902AX Triple Redundancy Module

I. Brand and Platform Positioning
Brand： Triconex (Inventec, now Schneider Electric EcoStruxure Safety System)
Compatible System: Tricon CX Triple Redundancy TMR Safety Instrumentation System SIS/ESD
Model Distinction
3902AX: With HART universal 16-channel I/O card
3902X: Same version, without HART basic version
Safety Level： SIL3 certified， specifically for critical safety control in petrochemicals， oil and gas， and power plants
Product Lifecycle： Main CX system in service， not discontinued； Spare parts are in ample supply

Core Hardware Specifications
1. Channel Characteristics (General Universal I/O)
Single card 16 independent programmable channels， each channel can be individually configured：
AI Analog Input： 4–20mA， thermal resistance RTD， thermal couple TC
AO Analog Output： 4–20mA (supports HART)
DI Digital Input： 24VDC/120VAC/240VAC switch quantity
DO Digital Output： 24VDC drive contact
Accuracy： Analog quantity ±0.1% FS， with temperature drift automatic compensation
2. TMR Triple Redundancy Architecture (Core Safety Feature)
Internal three independent signal acquisition circuits， hardware 2oo3 three-out-of-two voting
Single channel / single circuit failure does not affect the overall control， no single-point failure risk
Channel-to-channel 500VDC optical isolation， suppressing ground loops， strong electromagnetic interference
Full-channel real-time self-diagnosis： open circuit， short circuit， overrange， module power supply failure， bus anomaly
3. HART Communication Capability (AX suffix unique)
Built-in HART 5/7 protocol， compatible with intelligent valve positioners， transmitters
Remote reading of instrument diagnostics， configuration， calibration without opening the site
Support for uploading multi-variable instrument data to TriStation software
4. Electrical and Mechanical Parameters
Backplane Power Supply： 5V DC system bus power supply
Hot Swap： Supports online replacement of modules without downtime
Operating Temperature： -40℃ ~ +70℃， wide temperature adaptation for offshore platforms
Size： Standard Tricon CX slot card， high-density compact design
Matching Terminal： Compatible with Beckhoff H-System intrinsically safe isolation barrier terminal board， for use in explosive Ex ia hazardous zones
5. Software Configuration
Programming Software： TriStation 1131 (IEC61131 standard)
Configurable fault-safe output： fault hold / 4mA/20mA preset safety value
Automatic alarm for fault events， recording of fault timestamp

Core Advantages
Single Card Four-in-One： AI/AO/DI/DO universal， significantly reduces cabinet card types and reduces spare parts inventory
SIL3 TMR Hardware Redundancy， meeting ESD， F&G， boiler protection safety standards
HART Intelligent Instrument Integration， eliminating the need for separate HART acquisition card
Hot Swap Maintenance， factory continuous operation without downtime for maintenance
Intrinsically Safe Explosion-proof Solution， suitable for explosion-proof Zone 1 and Zone 2 in petrochemicals， oil and gas， and chemical industries

Typical Application Scenarios
Petrochemical / Refinery ESD Emergency Shutdown System： Control of regulating valves， cut-off valves
Oil and Gas Platform， Pipeline Fire and Gas F&G Detection Interlock
Thermal Power Boiler FSSS， Steam Turbine Overspeed Protection System
Chemical Plant Interlock， Reactor Safety Cut-off Control
Offshore Platform， LNG Storage Tank Safety Instrumented Loop