Woodward SST-DN4-104-2 DeviceNet Interface Card

Product Description

112005‑0048, also marked SST‑DN4‑104‑2, is a dual‑channel DeviceNet PC/104 network interface card originally developed by SST (now Molex), widely deployed within Woodward control systems for fieldbus communication. It follows the PC/104 stackable form factor, ODVA‑certified for DeviceNet protocol, supporting master (scanner) or slave mode on each independent channel. Powered by 5 VDC, it features galvanic isolation between bus channels and host bus, status LED indicators, and ruggedized hardware designed for continuous operation in industrial control cabinets. It is commonly used as a communication expansion board for Woodward governors and prime mover controllers.

Product Functions

• Dual independent DeviceNet communication channels, configurable as scanner/master or slave adapter
• Real‑time cyclic data exchange between host controller and DeviceNet field devices (sensors, I/O modules, actuators)
• Support standard DeviceNet baud rates: 125 kbps, 250 kbps, 500 kbps
• Network node management: node detection, fault reporting, bus error counters, and connection supervision
• PC/104 bus interface for direct stacking onto embedded CPU boards of industrial controllers
• Provide diagnostic status via on‑board LEDs for power, bus activity, and communication faults
• Isolated transceivers to suppress common‑mode noise and protect host electronics from bus surges

Application Scenarios

• Woodward turbine and diesel governor control systems adding DeviceNet fieldbus connectivity
• Land‑based generator control panels, combined‑cycle power plant control racks
• Marine auxiliary engine and generator control cabinets for shipboard distributed I/O
• Oil & gas prime mover control packages, compressor skid controllers
• Industrial retrofit projects upgrading legacy hard‑wired I/O to DeviceNet fieldbus architecture
• Embedded PC/104‑based industrial controllers requiring redundant or segregated DeviceNet networks

Common Issues

• Bus communication dropout: missing or improper 121Ω termination resistor, incorrect baud rate mismatch across network nodes
• Intermittent link faults: poor DeviceNet cable shielding, ground loops, or incorrect cable wiring (CAN‑H / CAN‑L swapped)
• Channel initialization failure: PC/104 stack bus conflict, incorrect memory mapping or interrupt settings on host CPU
• LED shows bus error: excessive bus load, duplicate MAC node addresses, or short circuit on field wiring
• Slow data refresh: oversized scan list, too many nodes configured, or bandwidth saturation on DeviceNet segment
• Card not detected at power‑up: unstable 5 V supply, loose PC/104 stack connector, physical misalignment during stacking
• Component ageing: degraded transceivers or solder joints after long‑term high‑temperature cabinet operation; refurbished units are typical replacement stock