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TRICONEX 3721/N/C Digital Input Module
Product Overview
The TRICONEX 3721/N/C is a high-reliability digital input module designed for integration into safety-critical industrial automation systems, specifically within Triple Modular Redundancy (TMR) architectures. As a key component of the TRICONEX Tricon safety system, this module serves as a critical interface between field sensors—including pressure switches, temperature detectors, and emergency stop devices—and the central control logic, enabling accurate and redundant data acquisition in high-risk environments. Certified to SIL 3 under IEC 61508 and IEC 61511 standards, the TRICONEX 3721/N/C meets the most stringent safety requirements, making it essential for applications such as emergency shutdown systems (ESD), fire and gas monitoring, and process interlock systems in industries like oil and gas, chemical processing, and power generation.
Equipped to handle 24VDC input signals, the TRICONEX 3721/N/C features 16 isolated input channels, each designed to detect both dry contact and voltage-based sensor inputs with high precision. Its compact physical design (12.4 cm x 19.8 cm x 8.6 cm) and lightweight construction (0.75 kg) allow for seamless integration into existing Tricon racks, supporting both new installations and system upgrades. The module’s robust build ensures reliable operation across a -40°C to +70°C temperature range, while its advanced diagnostic capabilities enable continuous monitoring of input integrity. By providing real-time, redundant data to the control system, the TRICONEX 3721/N/C forms a foundational element of safe and efficient industrial operations, ensuring rapid response to critical field events.
Technical Specifications
| Parameter | Value |
|---|---|
| Manufacturer | TRICONEX |
| Product Type | Digital Input Module |
| Input Voltage | 24VDC (nominal); 16–32VDC (operating range) |
| Number of Channels | 16 isolated channels |
| Physical Dimensions | 12.4 cm (height) x 19.8 cm (width) x 8.6 cm (depth) |
| Weight | 0.75 kg |
| Isolation Rating | 1500VAC galvanic isolation between channels and backplane |
| Operating Temperature | -40°C to +70°C |
| Safety Integrity Level | SIL 3 (IEC 61508/IEC 61511) |
| Response Time | <10 ms for input state changes |
| Humidity Tolerance | 5% to 95% non-condensing |
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Related Products
- TRICONEX 3706A: A 16-channel digital input module with enhanced diagnostic loopback testing for proactive fault detection.
- TRICONEX 3700A: A 32-channel high-density module for applications requiring extensive sensor monitoring.
- TRICONEX 3701A: Supports 120VAC input signals, ideal for legacy systems using alternating current sensors.
- TRICONEX 3720: Features non-supervised inputs for simplified wiring in auxiliary non-critical systems.
- TRICONEX 3722: Offers 48VDC input compatibility for industrial settings with higher voltage sensor networks.
- TRICONEX 4351B: A communication module enabling data transfer between Tricon systems and SCADA platforms.
- TRICONEX 8300A: A power supply module designed to provide stable power to Tricon input/output modules.
Main Features and Advantages
The TRICONEX 3721/N/C is distinguished by its TMR architecture, which incorporates three independent channels for critical components. This redundancy ensures that any single fault in a channel is automatically detected and compensated for, eliminating single points of failure and maintaining system availability. Its SIL 3 certification validates its ability to reduce risk in high-hazard processes, ensuring compliance with global safety regulations and providing operators with confidence in system reliability.
A key advantage of the TRICONEX 3721/N/C is its advanced diagnostic system, which continuously monitors input signals, channel health, and backplane communication. This allows for early identification of issues such as open circuits, short circuits, or sensor degradation, minimizing the risk of unplanned downtime. The module’s hot-swap capability further enhances operational flexibility, enabling replacement without powering down the Tricon rack—a critical feature for continuous-process industries where downtime is costly.
Environmental resilience is another core strength. The TRICONEX 3721/N/C operates reliably in extreme temperatures, high humidity, and high-vibration environments, making it suitable for harsh settings such as offshore platforms and chemical refineries. Its rugged design and long-term stability reduce maintenance needs, lowering lifecycle costs for end-users.
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Installation and Maintenance
Pre-installation preparations: Before installing the TRICONEX 3721/N/C, ensure the Tricon rack is powered off and properly grounded to prevent electrical damage. Inspect the module for physical defects, such as bent pins or damaged connectors. Verify compatibility with the system’s firmware version and clean the backplane connectors to remove dust or corrosion. Align the module with the rack’s guide rails and apply gentle pressure to seat the connectors fully, avoiding excessive force that could damage the backplane.
Maintenance suggestions: Regularly review system diagnostics via the Tricon configuration software to monitor TRICONEX 3721/N/C channel status and detect anomalies early. Perform firmware updates as recommended to address security enhancements and performance improvements. Clean the module’s exterior quarterly with a dry, lint-free cloth to prevent dust buildup, which can impede heat dissipation. For long-term storage, keep the module in an anti-static bag in a dry environment with temperatures between 0°C and 50°C. If a fault is detected, replace the module with a certified spare to maintain TMR integrity.
Application Fields
The TRICONEX 3721/N/C is widely utilized in safety instrumented systems (SIS) across high-risk industries. In oil and gas refineries, it monitors pressure relief valve positions, flame detector signals, and emergency shutdown triggers, ensuring rapid response to overpressure or fire incidents. In chemical plants, it integrates with toxic gas sensors and reactor temperature switches, enabling automated isolation of hazardous materials during process upsets.
Power generation facilities rely on the TRICONEX 3721/N/C to monitor turbine vibration sensors, boiler level switches, and generator protection relays, supporting safe shutdown sequences during equipment malfunctions. It also finds application in pharmaceutical manufacturing, where it monitors cleanroom pressure sensors and sterile process interlocks to maintain compliance with regulatory standards. By providing accurate, redundant input data, the TRICONEX 3721/N/C ensures safety systems make informed decisions, protecting personnel, equipment, and the environment from potential hazards.
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Product Guarantee
Our company offers a one-year quality warranty service for the TRICONEX 3721/N/C, covering hardware malfunctions not caused by human factors. During the warranty period, if the product shows abnormal performance or functional failure, we will provide replacement services promptly. As a leading industrial control distribution company established in 2007 with 17 years of experience, we maintain a large stock of TRICONEX 3721/N/C units and related spare parts. Our global supply chain network allows us to quickly respond to customers’ urgent needs for scarce or discontinued models, supporting the continuous and stable operation of industrial systems. For inquiries or quotations, contact us via Whatsapp: +86 18859254943 or E-mail: sales@ygplc.com.
