The Triconex 3723X is a Triple Module Redundancy analog input module with HART pass through capability. It is designed for use in the Tricon CX I/O expansion chassis. The module provides a dependable interface between field devices and the control system. It supports 32 single ended input channels. The input type covers 0 to 23 mA, and the input voltage range is 0 to 5 VDC. HART communication pass through allows connected HART enabled field devices to exchange digital information without disturbing the analog signal path. The front panel uses a yellow stripe for clear identification. The 3723X combines analog input measurement with HART data access. In a TMR architecture, three independent common cores process input signals. This structure supports high availability and fault tolerance. Each channel can receive a field signal and convert it into a digital value for the control system. The module is intended for installations where continuous process monitoring and safety related decisions are important. It can be used with compatible external termination panels and field external termination connectors. The design helps maintain measurement integrity while supporting intelligent field device communication. The module has 32 single ended inputs. Input type is 0 to 23 mA. The voltage range is 0 to 5 VDC. Input current range is 0 to 23 mA with a 250 ohm current to voltage resistor. Resolution is 16 bits. Input update rate is 50 ms. This includes an input filter of 47.5 ms and an update rate of 2.5 ms. Accuracy is less than 1 percent of full scale range from -20 to 60 degrees C. The module also references 0.75 percent of full scale range in fault detection behavior. Repeatability is less than 0.2 percent for one minute for a fixed input value. Input resistance is 10 Mohm minimum in DC and 420 kohm typical. Normal mode rejection is -3 dB at 25 Hz, -17 dB at 60 Hz, and -23 dB at 120 Hz. Input over-range measurement is 14 percent, from 0 to 5.75 V. Logic power is less than 11 watts. Input over-range protection is 150 VDC continuous and 115 VAC continuous. The module also supports 400 Vrms continuous, 566 V peak, and 1500 VDC for 60 seconds. These ratings help protect the module and maintain operation during abnormal field conditions. The design supports channel to channel isolation and robust signal integrity in industrial environments. The 0 to 23 mA input range provides headroom for over-range and under-range conditions, which is useful in process control and safety applications. The front panel includes Pass, Fault, Active, and Field LEDs. Each point has a load fault LED for over-range or under-range field input per Namur NE 43 and for HART field device faults. This point level diagnostics helps technicians identify field wiring problems, device faults, and module status. The module monitors input behavior and supports mis-compare detection in the TMR architecture. The minimum period of mis-compares is 50 samples. The input change sample period is 2.5 ms. These diagnostic functions help maintenance teams respond quickly and keep the process online. The 3723X compares readings across redundant paths. If an input sample changes by more than 0.75 percent of full scale range from the previous sample, the readings are not compared. Rapidly or continuously changing inputs may cause the time to detect a fault to increase. When a module becomes active during a board switch, accuracy can decrease momentarily to less than 3 percent of full scale range. Adding debouncing in the application can reduce the chance of spurious events. These behaviors are important for engineers who configure sampling, filtering, and fault logic in a redundant control system. HART pass through allows HART enabled field devices to send and receive HART digital information through the analog input module. This function supports device configuration, diagnostics, and maintenance data without a separate HART interface at the field wiring. The analog input path remains available for process measurement. The module is therefore suitable for smart transmitters that provide both a 4 to 20 mA analog signal and HART digital communication. This combination helps reduce wiring complexity and improves access to field device information. The 3723X is compatible with several termination options. These include the 9760X-210RF ETP kit with 32 points, the 9761X-210RF ETP kit with 16 points, the 9765X-210RF ETP kit with 32 points, the 9771X-210RF ETP kit with 16 points, the 9789X-610RF nonincentive ETP kit with 32 points, and the 9791X-610RF ETP kit with 16 points. The compatible field external termination connector is the 9769X FET with 32 points. FETs are required for installing I O modules in the Model 8131X I O Expansion Chassis and for connecting ETPs to the I O modules in that chassis. The 9771X-210RF and 9791X-610RF panels are also compatible with the module. Individual field power monitoring is not supported and must be turned off in TriStation. If it is turned on, the module will detect a fault. The Triconex 3723X is suited to process control and safety applications that require analog input measurement, redundancy, and HART device access. Typical uses include smart transmitter integration, process monitoring, and control loops where 0 to 5 VDC or 0 to 23 mA signals are present. Its TMR structure supports high availability, while point level diagnostics and LED status help reduce troubleshooting time. The module can operate in the Tricon CX I O expansion chassis with approved termination panels and FET connectors. With 16 bit resolution, 50 ms update rate, and HART pass through, it provides a practical balance of measurement performance and intelligent field device communication. Engineers should consider input filter timing, update rate, and debouncing when configuring the 3723X. The module accuracy can be affected briefly during a board switch, so application logic should tolerate a short period of reduced accuracy. Rapidly changing inputs may delay fault detection. If an input sample changes by more than 0.75 percent of full scale range from the previous sample, the readings are not compared. These notes help ensure stable operation in systems that use TMR voting and diagnostics. Proper configuration also helps avoid unnecessary fault events and supports long term reliability. The Triconex 3723X Analog Input Module with HART is a 32 channel, TMR analog input module for the Tricon CX I O expansion chassis. It supports 0 to 5 VDC input, 0 to 23 mA current input, 16 bit resolution, 50 ms update rate, HART pass through, point level fault LEDs, and multiple termination options. Its design supports fault tolerant control architectures, smart field device communication, and reliable analog measurement in industrial safety and process systems.Product Overview
System Role and TMR Architecture
Input and Measurement Specifications
Over-range, Protection, and Power
Diagnostics and LED Indication
Sampling Behavior and Fault Detection
HART Pass Through
Termination Options and Installation
Application Fit
Configuration Notes
Summary



