Description
The Triconex AI3351 is a high-performance, Triple Modular Redundant (TMR) Analog Input Module designed for critical safety and control applications. It provides 32 isolated input channels, making it a high-density solution for monitoring process variables in environments where system availability and safety integrity are paramount.
Product Parameters (Datasheet)
- Model Number: AI3351
- Module Type: TMR Analog Input (High Density)
- Number of Channels: 32, isolated
- Input Range: 0 to 5 VDC or 4 to 20 mA (via external termination)
- Resolution: 12-bit
- Input Impedance: > 10 MOhms
- Isolation: 1000 VDC (Channel-to-chassis)
- Scan Rate: 50 ms (nominal)
- Point-to-Point Accuracy: < 0.15% of FSR
- System Compatibility: Tricon v9.6 and higher / v10.x / v11.x systems
TRICONEX AI3351
TRICONEX AI3351
TRICONEX AI3351
Country of Origin
This safety-instrumented system (SIS) component is engineered and manufactured by Triconex (a brand of Schneider Electric) in the USA.
Application Fields
The AI3351 is specifically designed for high-integrity industrial safety loops:
- Emergency Shutdown (ESD): Reliable monitoring of pressure, level, and flow transmitters for safety trips.
- Fire and Gas (F&G) Systems: Integrating large arrays of gas detectors and flame sensors.
- Critical Process Control: Managing loops that require zero downtime and high fault tolerance.
- Turbo-Machinery Control: Monitoring auxiliary analog signals for large turbines and compressors.
- Nuclear Power: Applied in balance-of-plant monitoring where high channel density is required.
Product Usage Instructions
- Installation: Insert the module into a spare I/O slot in the Tricon chassis. Ensure the module is seated firmly to engage the backplane connectors.
- Termination: Use a 32-channel External Termination Panel (ETP). For 4-20 mA signals, ensure the ETP is equipped with the required precision shunt resistors.
- Software Configuration: In TriStation 1131, configure the slot for the AI3351 module and define the engineering units and alarm limits for each of the 32 channels.
- Redundancy Check: The TMR architecture handles internal voting automatically. Verify that the “PASS” LED is green, indicating all three internal “legs” are healthy.
- Hot Swapping: To replace a module, simply pull the existing module and insert the new one. The system will automatically synchronize the new module without interrupting the process.
Product Technical Description
The AI3351 utilizes the Triple Modular Redundant (TMR) architecture to provide fault-tolerant operation. Each of the 32 input signals is routed to three independent input branches (Legs A, B, and C). Each leg possesses its own microprocessor and A/D converter. The digitized values from all three legs are sent to the Main Processors, where they are compared and voted upon using a sophisticated median-selection algorithm. This process allows the system to identify, report, and ignore a failure in any single leg while maintaining continuous, accurate control. The “AI3351” model is favored for its high density, allowing 32 channels in a single slot, which optimizes footprint in large-scale control cabinets.
Q&A (Common Questions)
Q: What is the main benefit of the 3351 over the 3708EN? A: The AI3351 offers double the channel density (32 channels vs. 16 channels), making it more efficient for systems with high I/O counts.
Q: Does this module support HART data? A: No, the AI3351 is a standard analog input module. For HART digital communication, you would typically use the 3721 or 3723 modules.
Q: Can I mix voltage and current inputs on the same module? A: Yes, since the scaling is handled at the termination panel and within the software configuration for each individual point.
Q: What happens if the “FAULT” LED turns red? A: This indicates an internal hardware failure in one of the three legs. Because it is TMR, the system remains safe and operational, but the module should be replaced at the earliest convenience to restore full redundancy.
Similar Model Recommendations
- Triconex 3708EN (16-channel TMR AI)
- Triconex 3721 (HART Analog Input)
- Triconex 3351 (Standard 32-channel AI variant)
- Triconex 3805E (Analog Output Module)
- Triconex 3503E (Digital Input Module)
For current pricing and availability of the Triconex AI3351, please contact our technical sales team.
