5438-824 - 48-channel Discrete Input Module

SPECIFICATIONS:

Part Number: 5438-824
Manufacturer: Woodward
Series: MicroNet / MicroNet TMR
Product Type: TMR Discrete Input Module (48/24)
Input Channels: 48 Discrete Inputs
Excitation Voltage: 24 V dc or 125 V dc (Terminal board dependent)
Architecture: Triple Modular Redundant (TMR)
Isolation: 500 V ac (Channel-to-Chassis)
Input Filtering: 4 ms hardware filter
Operating Temperature: -30 °C to +65 °C (-22 °F to +149 °F)
Availability: In Stock
Country of Origin: USA

FUNCTIONAL DESCRIPTION:

The 5438-824 is a high-density TMR Discrete Input Module designed and manufactured for the Woodward MicroNet TMR (Triple Modular Redundant) system. As a fundamental component of the 48/24 I/O suite, it provides 48 independent discrete input channels. This module is designed for mission-critical turbine and engine control applications where the reliable sensing of contact states such as limit switches, pushbuttons, and auxiliary contacts is vital for both sequence-of-events (SOE) recording and protective logic.

TMR FAULT TOLERANCE & VOTING:

As a native TMR module, the Discrete Input Module operates within a triplicated control environment to ensure maximum system availability and safety.

• Redundant Sensing: Each field contact signal is fanned out to three independent acquisition paths within the module, communicating directly with the three redundant processors (R, S, and T).
• Hardware Voting: The system utilizes sophisticated hardware voting logic to compare the three internal readings. If one internal circuit fails or a signal path is compromised, the system identifies the outlier and continues to operate based on the remaining healthy paths.
• Fault Isolation: This architecture ensures that a single hardware fault within the module cannot result in a false tripped or cleared state being reported to the controller.

SIGNAL CONDITIONING & DIAGNOSTICS:

To ensure precision in electromagnetically noisy industrial environments, the Discrete Input Module incorporates:

• Hardware Filtering: Integrated filters eliminate contact bounce and high-frequency noise, ensuring that only valid state changes are processed by the GAP (Graphical Application Programmer) logic.
• Continuous Self-Tests: The module performs background diagnostics on its internal logic and communication interfaces. Any detected failure is immediately reported as a module alarm to the main controller.
• Contact Excitation: The module works in conjunction with the terminal board to provide the necessary excitation voltage to the field contacts, supporting both 24 V dc and 125 V dc configurations.

WIRING & INTERCONNECTIVITY:

The Discrete Input Module is typically paired with a dedicated TMR Discrete Input Terminal Board (DITB). Connection to the field is made via high-density cables that maintain signal integrity across the backplane. The module's mechanical design allows for easy installation and is fully compatible with the MicroNet TMR chassis's high-availability features.

WHY BUY FROM WOC:

WOC is a premier provider of legacy and current Woodward control hardware. We maintain a significant inventory of the 5438-824, available in both unused and professionally refurbished conditions. Each TMR discrete module undergoes rigorous testing on specialized simulators to verify channel-to-channel synchronization and confirm flawless TMR voting. Backed by a standard warranty and 24/7 technical support, we ensure your critical monitoring systems remain precise and reliable.

FREQUENTLY ASKED QUESTIONS:

What is the 5438-824?

It is a 48-channel Discrete Input Module designed for the Woodward MicroNet TMR system. It interfaces field contact signals into the redundant control processors for logic and monitoring.

How does the TMR voting system handle a single-channel failure?

Because the module triplicates the input signal to three processors, a single circuit failure is automatically outvoted by the other two. This prevents a hardware fault from causing a nuisance trip or an incorrect status report.

Is the Discrete Input Module hot-swappable?

Yes. In a TMR-configured MicroNet chassis, the Discrete Input Module supports hot-swapping. This allows maintenance personnel to replace a faulty module while the turbine is online without disrupting the control process.

What excitation voltages are supported by this module?

The module itself is designed to interface with signals conditioned by the terminal board. Depending on the DITB terminal board used, it can support either standard 24 V dc or high-voltage 125 V dc contact interrogation.