TRICONEX 3721 (SIS Analog Input Module · TMR Triple Modular Redundancy) Brand / Series: TRICONEX (Under Schneider Electric), Tricon Safety Control System Model: 3721 Type: 32-channel Differential Analog Input (AI), TMR Triple Modular Redundancy, SIL 3 Safety Level. ## I. Basic Parameters Input Channel: 32-channel differential, DC coupling Signal Range: Voltage: 0～5V DC (unipolar) or -5～+5V DC (bipolar) Current: 0～20mA (external 250Ω precision resistor required) Resolution: 12-bit / 14-bit (software programmable) Accuracy: <0.15% Full Scale (0～60℃) Update Rate: 10ms Isolation Withstand Voltage: Field to System: 800V DC; Isolation between channels Overvoltage Protection: Continuous withstand of 150V DC / 115V AC overvoltage Operating Temperature: -40℃～+70℃; Storage Temperature: -40℃～+85℃ Power Consumption / Dimensions / Weight: ≤15W; Approx. 146×89×30mm; Approx. 0.5kg Certifications: CE, UL, FM, CSA, ATEX, IECEx (SIL 3) ## II. TMR Redundancy & Diagnosis Triple Modular Architecture: Independent acquisition of each signal via 3 channels, 2-out-of-3 (2oo3) voting logic Single Point Fault Tolerance: Fault of any single channel will not affect system operation, no single point of failure Onboard Diagnosis: Channel short circuit / open circuit, over-range, power supply and internal circuit self-testing Front Panel LED: PASS/FAULT/ACTIVE/FIELD status indicators Hot Swappable: Supports live replacement without system shutdown ## III. Interface & Wiring Connector: 56-pin, matched with dedicated terminal boards (e.g. 9753-230) TriBus: High-speed redundant communication with Tricon Main Controller (3008/3501E) ## IV. Typical Applications SIS/ESD: Monitoring of critical process parameters such as pressure, temperature, flow and liquid level F&G Fire and Gas System: Signal acquisition for flammable gas, toxic gas and flame detectors Power / Oil & Gas / Chemical Industry: Unit interlock, boiler protection and compressor safety control Same-series Matching Devices: Main Controller 3501E/3008, DI 3503E, DO 3604E, Communication Module 4351B