Description
The Triconex 3723X is a 16-point, dual-redundant digital output module designed for high-availability applications within the Tricon platform. Unlike standard TMR (Triple Modular Redundant) modules that utilize three separate branches for a 2-out-of-3 vote, the “X” series modules employ a dual-redundant architecture. This specific hardware configuration is optimized for systems requiring supervised control or high-current switching while maintaining a compact footprint and SIL-rated safety performance.
Commercial and Availability Status
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Condition: New Original (Factory Sealed Surplus)
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Warranty: 12-Month Mechanical and Electrical Warranty
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Availability: In Stock
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Lead Time: Ships within 2 to 3 business days
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Pricing Note: Market pricing for Triconex hardware fluctuates based on global supply. Contact our sales department for a firm, project-specific quote.
Technical Specifications
| Parameter | Specification / Value |
| Model Number | 3723X |
| Output Channels | 16 points, dual-redundant |
| Output Type | Supervised, DC-sourced (Commoned) |
| Nominal Voltage | 24 V DC |
| Operating Range | 18 to 30 V DC |
| Maximum Current (Peak) | 2 A per point (4 A maximum for 10 ms) |
| Continuous Current | 1 A per point at 60 °C |
| Minimum Load Current | 10 mA |
| Leakage Current (OFF State) | < 2.0 mA |
| On-State Voltage Drop | < 1.5 V DC at 2 A |
| Diagnostic Indicators | PASS, FAULT, ACTIVE, LOAD (Supervision) |
| External Power Requirement | 24 V DC (Dual redundant feeds recommended) |
| Isolation | 1,500 V DC (Field-to-Logic) |
Technical Architecture and Supervision Features
The 3723X is designed for “Supervised” digital output control. In field deployments, this module doesn’t just switch a load; it continuously monitors the integrity of the loop between the controller and the field device (e.g., a solenoid or contactor).
Dual-Channel Hardware Logic
The module uses two independent output circuits for each point. Internally, these circuits are arranged to ensure that a single component failure—such as a shorted transistor—will not prevent the system from successfully de-energizing the load in a “Fail-Safe” scenario.
Output Loop Supervision
A critical feature of the 3723X is its ability to detect field-side faults:
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Open Circuit Detection: The module monitors for a minimum load current (10 mA). If the field wiring is severed or the solenoid coil burns out, the module triggers a supervised fault alarm.
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Short Circuit Protection: If the field load draws excessive current, the module enters a current-limiting state and reports a point-level fault to the Main Processor.
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Field Power Loss: The module monitors the presence of the 24 V DC field supply. If field power drops below the operational threshold, the module flags a system-wide diagnostic alarm.
Engineering and Installation Guidelines
1. External Termination Panels (ETP)
The 3723X must be paired with the correct External Termination Panel (typically an ETP 976x series). Using an incompatible ETP can interfere with the supervision circuitry, leading to false “Open Load” or “Field Power” alarms. Ensure the ETP supports the high-current demands if multiple channels are operating at 1 A simultaneously.
2. Commoning and Power Distribution
While the 16 outputs are independently controlled, they share a common field power return. In high-density cabinets, ensure the field power wiring is sized to handle the aggregate current of all 16 channels.
Expert Note: If all 16 channels on a 3723X are at full 1 A load, the total current draw is 16 A. Use a minimum of 12 AWG (4 mm²) wiring for the primary power feed to the termination panel to prevent excessive voltage drop.
3. Hot-Repair Procedures
The 3723X supports online hot-repair. When a fault is detected (indicated by the FAULT LED), a replacement module can be inserted into the adjacent slot.
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Wait for the replacement module to pass its self-test (solid PASS LED).
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The system will automatically transition control to the new module.
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Verify that the ACTIVE LED is illuminated on the new module before removing the faulty hardware.
Frequently Asked Questions
Why choose the 3723X over a standard 3700-series TMR module?
The 3723X provides a specific balance of high-current capacity (up to 2 A) and comprehensive loop supervision in a dual-redundant package. It is frequently selected for fire and gas (F&G) systems where detecting an open circuit in the field wiring is as critical as the ability to trigger the device.
Can I disable the “Open Load” supervision for unused points?
Yes. Within the TriStation 1131 software configuration, unused points should be disabled or bypassed to prevent the module from reporting “Open Load” errors. Alternatively, a dummy resistor can be installed on the termination panel to simulate a load current > 10 mA.
What does a flashing “LOAD” LED indicate?
A flashing LOAD LED typically indicates that the module has detected an anomaly in the field-side power or wiring. Check the 24 V DC field supply voltage at the termination panel and verify that all field fuses on the ETP are intact.
