Woodward 9905-968 Linknet Nodes and I/O Controller Module

The Woodward 9905-968, also cataloged as the 9905-968 Linknet Nodes and I/O Controller Module, operates as a dedicated hardware component for analog signal acquisition within Woodward control system platforms.

Hardware Specifications

Actuator Loop Feedback Response & Node Synchronization

The module interfaces directly with a distributed Linknet network topology, acquiring field data from 6 independent 4-20 mA analog channels without onboard 24 V loop power distribution. This variant depends entirely on external power isolation loops to drive the field transmitters, routing incoming current vectors into internal precision precision shunt instrumentation networks for conversion.

The digitized array is continuously mirrored over the Linknet fieldbus bus structure to synchronize with the master governor. This structural architecture feeds into the primary engine actuator loop feedback response loops, shifting raw process metrics such as fuel pressure, generator thermal values, or valve placement states directly into the host 2301D digital speed control computation cycle to adjust proportional throttle profiles without network latency lags.

Frequently Asked Questions

Q: Does the 9905-968 module support live hot-swap wire replacement while the Linknet fieldbus is actively polling? A: No. Severing terminal power or unseating the network communication links during engine operation drops the 6 analog feedback nodes instantly. This data disruption will break active loop execution in the host controller, triggering defensive fail-safe shutdowns or valve trip sequences.

Q: Can this specific module provide power to a standard 2-wire 4-20 mA temperature transmitter? A: No. This model is configured without an internal 24 V loop power supply. Field-side loops must rely on separate external 24 VDC power distribution terminal networks to drive active multi-wire field transmitters before routing the return loops back into the module signal pins.

Q: How does the internal controller address a sudden loss of connection over the Linknet network? A: The hardware monitors bus packet timing limits. If Linknet network communication fails, the module forces its 6 input registers to safe-state defaults, dropping diagnostic status flags over the remaining interfaces to alert the host governor of node termination.

Field Installation Guidelines

• Chassis Grounding Architecture: Bolt the sealed metal enclosure securely onto a clean, flat mounting layout inside the panel frame. Ensure metal-to-metal contact with the backplate to discharge high-frequency noise and electromagnetic fields directly into the primary system earth ground bus.
• External Loop Power Cabling: Feed all 4-20 mA sensor signal strings through an external fuse distribution block to route proper 24 VDC loop excitation voltage. Do not attempt to source loops directly from the communication rail terminals of the module.
• Linknet Data Line Shielding: Connect the high-speed distributed network wiring using dedicated shielded twisted-pair (STP) cabling. Ground the cable drain shield only at the single system-designated anchor terminal block, keeping the signal lines well isolated from heavy current motor starter wires.