Invensys TRICONEX 3721 Analog Input Module

Description

The Invensys TRICONEX 3721 Analog Input Module is a high-reliability component of the Triconex series Safety Instrumented System (SIS), engineered for critical industrial automation environments with strict safety requirements. Its core function is to receive analog signals from field sensors—including temperature, pressure, and flow signals—and convert them into digital signals for processing by control systems. Built with a Triple Modular Redundancy (TMR) design, the module delivers exceptional reliability to support continuous operation in high-stakes applications.

Key technical specifications include 32 differential DC-coupled input channels, supporting 0-5VDC unipolar voltage, -5 to +5VDC bipolar voltage, and 0-20mA current signals when paired with an external 250 ohm shunt resistor. It features a 10ms input update rate for fast data acquisition, and a programmable resolution selectable between 12-bit and 14-bit to meet varying precision needs. Operating in temperatures from 0 to 60 degrees Celsius, it maintains measurement accuracy better than 0.15% of full scale. The module also offers robust electrical protection and anti-interference performance: its common mode rejection ratio reaches -85dB from DC to 100Hz to resist industrial electromagnetic interference, input overvoltage protection can continuously withstand 150VDC or 115VAC, and it has a 10M ohm input resistance with excellent channel isolation to prevent signal crosstalk.