中文版
Phone: 
Email: 
WhatsApp: Description
TRICONEX 3721 Analog Input Module
Product Overview
The TRICONEX 3721 is an 8-channel analog input module designed for TRICONEX’s Tricon Triple Modular Redundancy (TMR) safety systems, a cornerstone of safety instrumented systems (SIS) in industrial automation. This module converts continuous analog signals—such as pressure, temperature, and flow—from field sensors into digital data that the Tricon controller can process, enabling precise monitoring of safety-critical variables in high-risk industrial processes.
As a key component of the Tricon TMR architecture, the TRICONEX 3721 integrates seamlessly with Tricon racks and processors like the TRICONEX 3008, ensuring redundant signal processing to eliminate single points of failure. It supports a range of analog input signals, including 4–20 mA, 0–10 V DC, and RTDs (Pt100), making it compatible with common industrial sensors used in oil refineries, chemical plants, and power stations.
Built to meet stringent safety standards, the TRICONEX 3721 is SIL 3 certified (IEC 61508) and operates in temperatures from -40°C to 70°C with humidity up to 95% (non-condensing). It features channel-to-backplane isolation (250 V AC) to resist electrical noise, ensuring accurate data even near large motors or high-voltage equipment. Though a legacy model, the TRICONEX 3721 remains vital for maintaining older Tricon systems, offering compatibility with both legacy and modern sensors to avoid costly full-system upgrades.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 3721 |
| Manufacturer | TRICONEX |
| Product Type | 8-Channel Analog Input Module (Tricon TMR System) |
| Number of Channels | 8 (isolated) |
| Input Signal Types | 4–20 mA, 0–10 V DC, RTDs (Pt100) |
| Resolution | 16-bit |
| Accuracy | ±0.05% of full scale |
| Isolation | 250 V AC (channel-to-backplane) |
| Physical Dimensions | 165 mm (L) × 105 mm (W) × 38 mm (D) |
| Weight | 0.65 kg |
| Operating Temperature | -40°C to 70°C |
| Humidity Tolerance | 5%–95% (non-condensing) |
| Power Supply | 24 V DC ±10% |
| Safety Integrity Level | SIL 3 (IEC 61508) |
| Mounting Type | Tricon rack mount (compatible with Tricon 1000/2000 racks) |
TRICONEX 3721
Related Products
- TRICONEX 3501E: A 24 V DC digital input module that works with the 3721 to integrate digital and analog data in safety systems, monitoring discrete sensors like emergency stop buttons alongside analog signals.
- TRICONEX 3604E: A 24 V DC digital output module that executes control actions based on data from the 3721, such as activating shutdown valves when pressure readings exceed safe limits.
- TRICONEX 3008: The Tricon TMR main processor module that processes analog data from the 3721 to run safety logic, ensuring system-wide coordination in emergency scenarios.
- TRICONEX 3700: An 8-channel analog input module with similar functionality to the 3721 but with broader thermocouple support, serving as an alternative for systems using J/K/T type sensors.
- TRICONEX 3201: A communication module that connects the 3721 to SCADA systems, enabling remote monitoring of analog signals (e.g., pipeline flow rates) via Modbus or Ethernet.
- TRICONEX 3721E: An upgraded version of the 3721 with enhanced noise filtering, designed for modernized systems requiring higher signal integrity in extremely noisy environments.
Main features and advantages
Triple Modular Redundancy (TMR): The 3721 uses TMR technology, with three independent channels processing each analog signal simultaneously. This redundancy ensures that if one channel fails, the other two validate and use the correct data—critical for safety-critical applications like monitoring reactor temperatures in chemical plants, where incorrect readings could lead to catastrophic failures.
High precision measurements: With 16-bit resolution and ±0.05% accuracy, the 3721 captures tiny changes in analog signals, such as 0.01 mA shifts in a flow transmitter or 0.1°C variations in a turbine’s temperature. This precision is essential for maintaining tight process tolerances in industries like pharmaceuticals, where even small deviations can compromise product quality.
SIL 3 certification: Certified to IEC 61508 SIL 3, the 3721 meets the highest safety standards, making it suitable for applications where failure could harm personnel or the environment—such as monitoring pressure in offshore oil pipelines.
Broad signal compatibility: The module supports 4–20 mA, 0–10 V DC, and Pt100 RTDs, allowing direct connection to most industrial sensors without external converters. This reduces hardware complexity and setup time in mixed-sensor systems, such as power plants monitoring both temperature (RTDs) and pressure (4–20 mA transmitters).
Rugged industrial design: The 3721 operates in temperatures from -40°C to 70°C and resists humidity and dust, ensuring reliability in extreme environments—from arctic oil fields to desert solar power plants. Its robust construction minimizes downtime due to environmental stress.
Hot-swappable capability: The 3721 can be replaced while the system runs, allowing maintenance teams to swap faulty modules without shutting down critical processes. This feature is invaluable for continuous operations like oil refining, where unplanned shutdowns cost millions in lost production.
TRICONEX 3721
Installation and maintenance
Pre-installation preparations: Verify the 3721 is compatible with your Tricon rack (e.g., Tricon 2000) and power supply (24 V DC ±10%). Power off the system and disconnect all power sources. Align the module with an empty slot in the rack and push firmly until it clicks into the backplane. Connect sensors to the terminal block, matching each to a channel and following wiring diagrams (e.g., RTDs require 3-wire connections, 4–20 mA sensors use signal and common terminals). Ground sensor shields to reduce electrical noise.
Maintenance suggestions: Inspect the 3721 quarterly. Wipe dust from the module with a dry cloth to prevent overheating. Check terminal screws to ensure tight connections—loose wires can cause signal drift (e.g., inaccurate pressure readings). Use Tricon’s diagnostic software to monitor channel health; if a channel shows errors, test the connected sensor first. If the sensor works, power off the system, remove the 3721, and reinsert it to fix backplane connection issues. Store a spare 3721 in a dry, cool area (10–30°C) to enable quick replacement during failures, minimizing process interruptions.
Application fields
The TRICONEX 3721 is widely used in industries where precise analog monitoring is critical for safety and efficiency:
- Oil and gas: In onshore refineries, it monitors 8 pressure sensors in crude oil pipelines. The TMR design ensures accurate data, triggering automatic shutdowns if pressure spikes indicate a potential leak.
- Chemical processing: In petrochemical plants, the 3721 tracks 8 temperature sensors in a polymer reactor. Its high accuracy ensures temperatures stay within a 0.5°C range, preventing material degradation or dangerous exothermic reactions.
- Power generation: In nuclear power plants, it monitors 8 coolant flow rates via 4–20 mA transmitters. The module’s SIL 3 certification ensures it reliably feeds data to safety systems, which adjust pumps to maintain optimal coolant levels.
- Water treatment: In municipal wastewater plants, the 3721 measures 8 pH sensors in filtration tanks. Its rugged design resists humidity, ensuring consistent readings that guide chemical dosing systems to maintain water quality standards.
TRICONEX 3721
Product guarantee
Our company offers a one-year quality warranty service for the 3721, 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. In addition, for discontinued models or urgent demands, relying on our global supply chain network, we can quickly respond to customers’ procurement needs for scarce spare parts, and provide reliable services to support the continuous and stable operation of industrial systems.
Our company is a leading enterprise in the industrial control industry, established in 2007, has been 17 years. We are an import and export trade distribution company, mainly selling major brands of industrial control parts, there are many unpopular discontinued models, with a large stock. Our company has the advantage of supply channels, a large number of spot, to meet the needs of customers anxious to find spare parts. Our main PLC module, DCS card, ESD system card, vibration monitoring system card, turbine control system module, gas generator spare parts, instruments and other products distribution trade.
For inquiries, contact us via WhatsApp at +86 18859254943 or email at sales@ygplc.com.
