Woodward 5441-693 Discrete I/O Module – 24DI/12DO Relay Field Terminal for MicroNet TMR

Brand WOODWARD

Model Woodward 5441-693

Product Overview

The Woodward 5441-693 is a high-density Discrete I/O Field Terminal Module engineered for Woodward’s MicroNet and MicroNet Plus turbine control platforms. As a critical interface between field discrete signals and the TMR (Triple Modular Redundant) control architecture, the Woodward 5441-693 captures 24 optically isolated discrete input channels and drives 12 Form-C relay output channels, serving as the primary binary signal gateway for turbine trip logic, breaker auxiliary feedback, and valve limit switch monitoring. This module is specifically designed for applications where plant safety, signal integrity, and long-term reliability are paramount.

In the MicroNet TMR architecture, the Woodward 5441-693 does not execute control logic independently. Instead, it requires paired TMR5200 CPU boards to process channel data over the RTN shared I/O bus. The module operates as a single-slot, hot-swappable card within the MicroNet TMR chassis, allowing online replacement without interrupting the RTN bus or the active control program. Its full through-hole PCB construction distinguishes it from compact surface-mount I/O cards, providing enhanced resistance to continuous vibration in turbine hall environments.

The Woodward 5441-693 is recognized as a critical spare for legacy turbine control systems still operating in power generation facilities worldwide. With OEM field logging recording a 56,000-hour MTBF under steady 50°C cabinet runtime, the Woodward 5441-693 has established a reputation for sustained reliability in demanding continuous-process applications. As the direct upgrade replacement for the older 5441-629 model, it remains an active production item (not EOL) for many configurations, ensuring continued availability for maintenance and system expansion .

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Description

Technical Specifications

Parameter Name	Parameter Value
Product Model	Woodward 5441-693
Manufacturer	Woodward
Product Type	HD Discrete I/O Field Terminal Module
Series	MicroNet / MicroNet Plus / Vertex-Pro
Digital Input Count	24 optically isolated discrete inputs
Relay Output Count	12 Form-C (SPDT) relay outputs
Input Signal Type	24VDC dry contact, sinking/sourcing configurable
Relay Contact Rating	10A @ 28VDC, 5A @ 250VAC (resistive)
Input Update Time	5 ms
Time Stamp Resolution	1 ms
Isolation Voltage	500V–2500V (input/output to backplane)
Contact Supply	Isolated 24VDC, 400mA maximum
Operating Temperature	-40°C to +70°C
Dimensions (W×H×D)	Approx. 158.75 × 88.9 × 69.85 mm
Weight	Approx. 0.28–1.0 kg (variant dependent)
Hot Swap	Supported (MicroNet TMR certified)

Main Features and Advantages

High-Density Discrete Signal Capture: The Woodward 5441-693 packs 24 optically isolated discrete input channels into a single MicroNet personality card, enabling comprehensive monitoring of breaker auxiliary contacts, valve limit switches, pressure switches, and emergency stop circuits without requiring multiple modules. Each input channel draws only 4mA at 24VDC, minimizing load on field wiring while maintaining reliable signal detection. The 5ms update time with 1ms timestamp resolution ensures that sequence-of-events (SOE) recording captures the precise timing of turbine trip events and interlock actuations, which is essential for post-event analysis in critical power generation applications .

Robust Relay Output Architecture: The Woodward 5441-693 provides 12 independent Form-C relay outputs rated at 10A per channel at 28VDC resistive load, capable of directly driving trip solenoids, alarm annunciators, and auxiliary contactors without intermediate interface relays. The SPDT configuration allows each output to be wired as normally-open or normally-closed, providing flexibility in fail-safe circuit design. Field-replaceable relays reduce maintenance downtime by allowing individual relay replacement without scrapping the entire module, a significant cost advantage in legacy turbine control systems where spare availability is limited .

Vibration-Hardened Through-Hole Construction: Unlike modern surface-mount I/O cards optimized for compactness, the Woodward 5441-693 utilizes full through-hole PCB assembly. This construction choice is deliberate—through-hole solder joints exhibit superior mechanical fatigue resistance under continuous vibration, making the module suitable for mounting directly in turbine hall cabinets where operational vibration is a constant environmental factor. The OEM specification of 56,000-hour MTBF under steady 50°C runtime, approximately 8% higher than comparable surface-mount discrete modules, reflects the durability benefits of this design philosophy .

Complete Galvanic Isolation and EMC Protection: The Woodward 5441-693 maintains 500V–2500V isolation between field discrete circuits and the TMR backplane logic, protecting the redundant control architecture from electrical transients, ground faults, and common-mode noise on field wiring. Integrated protection circuits include input wetting overcurrent fuses, backplane reverse polarity lockout, and relay coil transient suppression diodes. The module carries UL, CE, and ATEX Zone 2 certifications with EN61000 Class A industrial EMC filtering, ensuring compl