Woodward 9905-971 Discrete Input Module | 24 Channels

Woodward 9905-971 Technical Overview

The Woodward 9905-971 is an industrial-grade Discrete Input Module designed by Woodward for critical control systems. Featuring a lightweight construction of approximately 0.45 kg (1.0 lbs), it accepts up to 24 contact inputs operating at 24 VDC wetting voltage with a fast 5 ms update time and 1 ms time-stamping resolution. Built with latent fault detection across its relay outputs, this module disengages safely via front-panel ejector handles and secures directly into the control chassis motherboard.

Part Number Breakdown

• 9905: Woodward Control Hardware & I/O Module Series
• -971: Specific Model Designator — 24-Channel 24 VDC Discrete Input Transducer Board

Technical Specifications Table

Key Features & Hardware Configurations

Features 24 isolated inputs, 24VDC wetting, latent fault relay detection, 0.45 kg weight, 5ms update time, and USA origin.

Frequently Asked Questions (FAQs)

Q1: What are the main specs of the Woodward 9905-971 module?
A1: 24 discrete channels, 24 VDC input voltage, 5 ms update time, 1 ms time-stamping, and 0.45 kg weight.

Q2: How does latent fault detection work on this module?
A2: It uses a series-parallel relay configuration with readback circuitry to test relays without altering output state.

Q3: How is contact wetting power provided to the discrete inputs?
A3: Power can be sourced internally (via terminal jumpers 33–35) or externally via 18–32 VDC / 100–150 VDC.