Yokogawa SNB10D-445/CU2T Safety Node Unit | ProSafe-RS SIL 3

Yokogawa SNB10D-445/CU2T Safety Node Unit - ProSafe-RS Architecture

The Yokogawa SNB10D-445/CU2T Safety Node Unit delivers distributed I/O expansion for ProSafe-RS safety instrumented systems, supporting up to 445 safety I/O points through dual-redundant ESB bus architecture. This SIL 3-certified node unit enables scalable, geographically distributed safety logic execution across oil & gas facilities, chemical plants, and power generation installations where remote I/O placement reduces wiring costs and improves system reliability.

Technical Specifications

• Model Number: SNB10D-445/CU2T
• Safety Integrity Level: SIL 3 certified per IEC 61508
• I/O Capacity: Up to 445 safety I/O points (configurable mix of DI/DO/AI/AO)
• Bus Architecture: Dual-redundant ESB (Enhanced Safety Bus) with automatic failover
• Communication Speed: 12 Mbps fiber optic transmission
• Node Distance: Up to 10 km between nodes via fiber optic cable
• Scan Cycle: 50-200 ms depending on I/O configuration
• Redundancy Configuration: 1oo2D (one-out-of-two with diagnostics)
• Connector Type: CU2T (copper twisted-pair terminator included)
• Operating Temperature: -20°C to +60°C (-4°F to +140°F)
• Power Supply: 24 VDC, dual-redundant inputs
• Diagnostic Coverage: >99% for systematic and random hardware failures
• MTBF: >100,000 hours under normal operating conditions

Advanced Features & Capabilities

Distributed Safety Logic Execution: The SNB10D-445/CU2T processes safety logic locally at the node level, reducing network traffic to the central safety controller while maintaining deterministic response times for time-critical shutdown sequences in emergency scenarios.

Hot-Swappable Redundancy: Dual-channel ESB bus connections ensure continuous operation during single-point failures. Automatic bus switchover occurs within 100 milliseconds without process interruption, enabling online maintenance of communication pathways.

Flexible I/O Allocation: Supports heterogeneous I/O module combinations including digital inputs (SDV144 series), digital outputs (SDV531 series), analog inputs (SAI143 series), and analog outputs (SAO144 series), allowing customized safety system architectures tailored to specific application requirements.

Integrated Diagnostics: Continuous self-monitoring detects communication errors, power supply anomalies, I/O module failures, and wiring faults. Diagnostic data transmits to engineering workstations via Modbus TCP/IP for predictive maintenance and troubleshooting efficiency.

Industrial Safety Applications

Emergency Shutdown Systems (ESD): Manages distributed shutdown logic across multi-unit refineries and offshore platforms, coordinating valve actuators, pump trips, and compressor shutdowns through geographically dispersed I/O points while maintaining SIL 3 integrity.

Fire & Gas Detection Networks: Processes inputs from hundreds of flame detectors, smoke sensors, and toxic gas monitors distributed across large industrial complexes, executing zoned suppression activation and evacuation protocols with sub-second response latency.

Burner Management Systems (BMS): Controls distributed ignition sequences, flame monitoring, and fuel valve interlocks for multi-burner industrial furnaces and boiler installations, preventing explosive atmospheres through precise fuel-air ratio control at each burner location.

Pipeline High Integrity Pressure Protection (HIPPS): Monitors pressure transmitters along extended pipeline routes, commanding rapid isolation valve closure before overpressure conditions trigger mechanical relief systems, protecting downstream equipment from catastrophic failures.

System Integration & Architecture

The SNB10D-445/CU2T integrates seamlessly into ProSafe-RS safety system hierarchies, connecting to duplexed safety control units (SSC10D/SSC50D) via redundant ESB bus infrastructure. Each node supports up to 16 I/O modules in local racks, with expansion capabilities through additional node units for systems requiring thousands of safety I/O points.

For complete safety system deployment, combine this node unit with Yokogawa SSC50D-S2543 Duplexed Safety Control Unit for central safety logic processing, Yokogawa ANB10D-425/CU2T Dual-Redundant ESB Bus Node Unit for standard I/O expansion, and Yokogawa SSC10D-S2111 Duplexed Safety Control Unit for compact safety controller configurations.

Installation & Configuration

Rack-mountable design fits standard 19-inch industrial enclosures with DIN rail mounting options for field junction boxes. ProSafe-RS engineering software (ToolboxST) provides graphical configuration of I/O assignments, safety logic distribution, and diagnostic thresholds. Commissioning includes automatic bus topology detection and I/O module verification.

Compliance & Certifications

IEC 61508 SIL 3 certified | IEC 61511 compliant for process industry safety | ATEX Zone 2 approved | IECEx certification for hazardous areas | CE marked | UL 508 listed | GOST-R certified | DNV-GL type approved for offshore installations

© 2025 INDUSTRIAL CONTROL HUB. All rights reserved.
Original Source: https://www.indctrlhub.com
Contact: sales@indctrlhub.com | +0086 18359243191