Description

9905‑972 Woodward LinkNet 6‑Channel Analog Output Module

Technical Specifications

• Part Number: 9905‑972
• Brand: Woodward (USA)
• Warranty: One Year
• Input Voltage: 24 VDC nominal supply via LinkNet fieldbus node; max 12 W power consumption
• Operating Temperature: ‑40 °C ~ +70 °C cabinet‑mount; DIN‑rail TS35 installation
• Storage Temperature: ‑40 °C ~ +85 °C
• Response Time: Deterministic analog output update synchronized with LinkNet bus cycle
• Protection Class: IP20 industrial node module; transparent front cover; metal DIN‑rail base
• Accuracy Class: ±0.2 % full scale; 12‑bit resolution for 4‑20 mA analog output
• Output Frequency: 6‑channel 4‑20 mA analog output; supports over‑range for valve positioner drive
• Rated Current Range: Each channel 4‑20 mA current output; short‑circuit and over‑voltage protection per channel
• Communication Interface: Woodward LinkNet fieldbus port; removable screw‑clamp terminal blocks; front‑panel network / channel‑status LED indicators
• Supported Protocols: Woodward proprietary LinkNet; compatible with 505 / 505E turbine‑generator control systems; simplex / dual‑redundant architectures supported
• Overload Capacity: Channel‑level transient‑voltage suppression; bus‑fault monitoring; hardware watchdog; no channel‑to‑channel galvanic isolation
• Dimensions: 160 mm × 100 mm × 40 mm; weight approx 0.59 kg

Product Overview

The 9905‑972 is a LinkNet distributed 6‑channel analog output node for Woodward 505 / 505E turbine control systems. It receives digital control commands from main controller over LinkNet fieldbus and converts to 4‑20 mA analog signals to drive valve positioners, I/P converters and modulating field actuators. Removable terminal blocks enable module swap without re‑crimping field cables. On‑board diagnostics detect loop open‑circuit, short‑circuit and out‑of‑range faults and report alarms back to turbine HMI workstation.

This module addresses distributed‑control challenges: remote analog modulating output via LinkNet fieldbus, simplified cabinet wiring for turbine skid layout, and drop‑in spare‑part compatibility for legacy 505/505E retrofit‑maintenance projects. Turbomachinery‑control engineers, power‑plant maintenance technicians and system‑retrofit integrators benefit most. It applies for steam‑turbine, gas‑turbine and compressor‑control anti‑surge, governing‑valve modulating‑control loops in power‑utility and petrochemical facilities.

Key Application Notes

• LinkNet remote I/O node; must connect to Woodward 505 / 505E main controller; cannot operate standalone
• 6‑channel 4‑20 mA analog output; no channel‑to‑channel galvanic isolation
• Not hot‑swap capable: 24 VDC power must be removed before module replacement
• Removable terminal blocks reduce field‑rewiring work during spare‑part replacement
• Configurable fail‑safe output setting: upscale, downscale or hold‑last‑value upon bus‑loss / hardware‑fault
• OEM original production is discontinued; widely‑used aftermarket spare for existing 505/505E maintenance‑retrofit projects
• Conformal‑coated PCB variant available for high‑humidity, high‑contaminant cabinet environments
• Commissioning must follow Woodward LinkNet installation manual for bus‑termination resistor setting