TRICONEX 3723X 32-Channel TMR Analog Input Module with HART
The TRICONEX 3723X is a Triple Modular Redundant (TMR) analog input module designed for the Tricon CX safety system. It is part of the Tricon CX I/O architecture and is intended for installation in the system's I/O expansion chassis. The module provides 32 single-ended analog input signals and incorporates HART communication capability for compatible field instruments.
The 3723X is designed for applications where analog process measurements need to be acquired by a fault-tolerant safety control system. Typical process variables represented by analog transmitters include pressure, flow, level and other continuously measured process conditions. By providing analog signal acquisition together with diagnostics and HART pass-through capability, the module forms an interface between field instrumentation and the Tricon CX control architecture.
According to Tricon CX technical documentation, the 3723X is specified as a 0–5 VDC analog input module with HART. Its input circuitry also supports current measurement from 0 to 23 mA when used with the specified 250 ohm I/V resistor arrangement. The module provides 16-bit resolution and uses a TMR architecture suitable for safety-related I/O applications.
Product Overview
| Manufacturer | TRICONEX / Schneider Electric |
|---|---|
| Model | 3723X |
| Product Type | TMR Analog Input Module with HART |
| System | Tricon CX |
| Installation | Tricon CX I/O Expansion Chassis |
| Input Channels | 32 single-ended analog input signals |
| Input Voltage Range | 0–5 VDC |
| Input Current Range | 0–23 mA with 250 Ω I/V resistor |
| Resolution | 16 bits |
| HART | HART v7 compatible, pass-through communication |
| Module Color Code | Yellow stripe |
TRICONEX 3723X Analog Input Function
The primary function of the 3723X is to acquire analog signals from field devices and make the corresponding process information available to the Tricon CX system. Each channel is configured as a single-ended analog input. The module can process voltage signals within the specified 0–5 VDC range and can also accommodate current measurement through the appropriate input conversion arrangement.
Analog input modules are important in safety and process-control systems because many field instruments generate continuously varying signals rather than simple discrete states. A pressure transmitter, for example, may provide a signal corresponding to the measured pressure. The safety controller can then use this information as part of process monitoring, alarm logic, permissive logic or other configured control functions.
The 3723X combines analog acquisition with TMR system architecture. The Tricon CX platform uses redundant processing and I/O structures to support fault-tolerant operation. The analog input module therefore operates as part of a larger safety-system architecture rather than as an independent general-purpose data acquisition device.
32-Channel Analog Input Architecture
The TRICONEX 3723X provides 32 single-ended input signals. This channel density allows a single module position to interface with a relatively large number of analog field signals while maintaining the architecture required by the Tricon CX system.
The documented input voltage range is 0–5 VDC. For current-based instrumentation, the module supports a 0–23 mA input range when used with a 250 Ω I/V resistor. This configuration accommodates the signal range associated with common industrial current-loop instrumentation while also allowing the module to detect input conditions beyond the normal measurement range.
The input over-range measurement capability extends to approximately 14 percent above the nominal 0–5 VDC range, corresponding to a measurement range up to approximately 5.75 V. Input over-range protection is specified for 150 VDC continuous and 115 VAC continuous under the documented conditions.
HART Communication
One of the distinguishing features of the 3723X is its integrated HART capability. The module provides HART pass-through communication to compatible HART-enabled field devices connected to the analog input channels.
The technical documentation specifies 32 HART modems, one per point, with compatibility with HART version 7. The HART pass-through identification includes the name string “Triconex AI 3723/X” and the documented device type code. This arrangement allows the analog measurement function and HART communication path to coexist within the same field interface architecture.
HART communication can provide additional information from compatible field instruments beyond the primary analog process value. Depending on the connected device and system configuration, this can support access to instrument information and diagnostic data without requiring a separate analog input module for the basic measurement channel.
TMR Safety Architecture
The 3723X is a TMR module. Triple Modular Redundancy is a fundamental architecture used by Triconex safety systems to improve fault tolerance and availability. In a TMR system, redundant processing and I/O paths can be used to identify discrepancies and maintain system operation when a fault occurs in an individual path.
The analog input module incorporates diagnostic functions intended to identify abnormal input behavior and module-related conditions. The documented diagnostic specifications include a minimum input change of 0.75 percent of full-scale range and a minimum period of mis-compare detection based on the specified sampling characteristics.
These functions are important when analog measurements are used in safety-related logic because the system must distinguish between legitimate process changes and abnormal signal behavior. The detailed diagnostic response depends on the overall Tricon CX configuration and application programming.
Electrical and Measurement Specifications
| Specification | 3723X |
|---|---|
| Number of Inputs | 32 single-ended |
| Voltage Input | 0–5 VDC |
| Current Measurement | 0–23 mA with 250 Ω I/V resistor |
| Resolution | 16 bits |
| Input Update Rate | 50 ms, with documented 2.5 ms update sampling characteristics |
| Accuracy | Less than 1% of FSR from −20°C to +60°C |
| Repeatability | Less than 0.2% for one minute at a fixed input value |
| Input Resistance | 10 MΩ minimum DC load |
| Field-to-System Ground Isolation | 400 Vrms continuous; 1500 VDC for 60 seconds |
| HART | 32 HART v7 modems, one per channel |
| Logic Power | Less than 11 W |
Termination and Field Interface
The 3723X is designed to operate with specified Tricon CX termination equipment. Documented compatible termination options include the 9760X-210RF ETP kit, 9761X-210RF ETP kit, 9765X-210RF ETP kit, 9771X-210RF ETP kit, 9789X-610RF nonincendive ETP kit and 9791X-610RF ETP kit, depending on the installation configuration.
The 9769X field external termination connector is also identified as a compatible FET for the 3723X. These termination components provide the interface between field wiring and the I/O module and should be selected according to the specific Tricon CX chassis and field termination arrangement.
Installation in Tricon CX
The TRICONEX 3723X can be installed only in the Tricon CX I/O expansion chassis according to the referenced Tricon CX documentation. It is therefore important to distinguish this model from similarly numbered analog input modules used in other Triconex product generations.
The 3722X and 3723X are both 32-channel analog input modules within the Tricon CX family, but their functions are different. The 3722X is documented as a fast 0–5 VDC analog input module without HART, while the 3723X adds HART communication capability. This distinction is important when selecting a module for an existing installation.
Application Areas
The 3723X can be used where continuous analog process measurements need to be acquired by a Tricon CX safety system. Typical industrial applications may include process plants, energy facilities, oil and gas installations, chemical processing systems and other applications where safety-related instrumentation is integrated with a fault-tolerant control architecture.
The module can interface with suitable analog transmitters and HART-enabled field devices. Its combination of 32 analog channels, TMR architecture, diagnostics and HART pass-through makes it suitable for systems where both process measurement and instrument communication are required.
Identification and Replacement
When identifying a TRICONEX 3723X, the complete model designation should be checked against the system documentation. The most important characteristics are the 3723X model number, Tricon CX compatibility, 32-channel analog input architecture and HART capability.
The distinction between 3723X and other Triconex analog input modules is particularly important during replacement. A module with a similar appearance or similar channel count may have a different signal range, communication capability or chassis compatibility. The system configuration, termination equipment and application requirements should therefore be checked before installation.
Summary
The TRICONEX 3723X is a 32-channel TMR analog input module with HART for the Tricon CX safety system. It provides 0–5 VDC analog input capability, supports 0–23 mA measurement through a 250 Ω I/V resistor, provides 16-bit resolution and incorporates 32 HART v7 communication channels.
Designed for installation in the Tricon CX I/O expansion chassis, the 3723X combines analog signal acquisition, HART pass-through communication, isolation, input protection and diagnostic functions within the Triconex TMR architecture. Its documented characteristics make it an important interface module for safety-related process instrumentation requiring reliable analog measurement and field-device communication.
