Yokogawa ProSafe-RS SNB10D Modules - SNB10D-413/CU2N/ATD0C

Technical Dossier

Product Details And Specifications

Yokogawa ProSafe-RS SNB10D Series Technical Notes

The Yokogawa ProSafe-RS system is a Safety Instrumented System (SIS) platform certified to IEC 61511 and IEC 61508 SIL 3, deployed across global heavy industries including petrochemical complexes, LNG terminals, nuclear power facilities, offshore platforms, and refinery units. The SNB10D Safety Node Unit is the core field-side controller within the ProSafe-RS architecture, responsible for executing safety logic, managing I/O communication, and maintaining fail-safe states under fault conditions. Its distributed node topology allows installation in hazardous areas close to field instruments, reducing wiring costs while maintaining SIL 3 integrity. ProSafe-RS installations are documented across major EPC contractors and end-user sites in Asia, the Middle East, and Europe, making the SNB10D one of the most widely deployed safety node platforms in the process industry.

The Evolution of ProSafe-RS SNB10D Architecture

Yokogawa introduced the ProSafe-RS platform in the early 2000s as a successor to its legacy ProSafe-EX and ProSafe-SLS safety systems. The SNB10D node unit was developed to address the limitations of centralized safety controllers by distributing safety logic execution to field-mounted nodes communicating over a dedicated Vnet/IP safety network.

Early SNB10D variants operated on a single-channel architecture with external redundancy options. Subsequent hardware revisions introduced dual-redundant CPU configurations (CU2N suffix), enhanced diagnostics coverage, and expanded I/O capacity. The ATD0C suffix denotes the analog terminal board configuration, supporting 4–20 mA HART field devices. Later firmware generations added support for partial stroke testing (PST) of emergency shutdown valves and tighter integration with the CENTUM VP DCS platform via the Integrated Gateway Unit (IGU).

ProSafe-RS SNB10D Full Catalog & Functionalities (SKU List)

Safety Node Units (SNB10D — Core Controllers)

• SNB10D-413/CU2N/ATD0C: Dual-redundant CPU safety node, analog terminal board, SIL 3 rated field controller.
• SNB10D-413/CU2N/DTD0C: Dual-redundant CPU safety node with digital terminal board for discrete I/O applications.
• SNB10D-413/CU1N/ATD0C: Single-CPU safety node, analog terminal board, standard SIL 2/3 field deployment.
• SNB10D-413/CU1N/DTD0C: Single-CPU safety node, digital terminal board, discrete field I/O configuration.
• SNB10D-413/CU2N/ATD1C: Dual-redundant CPU node, extended analog terminal board with HART pass-through support.
• SNB10D-413/CU2N/DTD1C: Dual-redundant CPU node, extended digital terminal board, 32-channel DI/DO capacity.

I/O Modules (Field Interface)

• SAI143-H00: 8-channel analog input module, 4–20 mA HART, SIL 3 rated, for SNB10D node integration.
• SDV144-H00: 16-channel digital input module, 24 VDC, high-density discrete input for ESD logic.
• SDO144-H00: 16-channel digital output module, 24 VDC, relay-driven discrete output for final elements.
• SAO141-H00: 4-channel analog output module, 4–20 mA, for positioner and control valve interfaces.
• SBI141-H00: Solenoid valve driver module, 24 VDC, integrated diagnostics for ESD valve actuation.
• STB144-H00: Terminal board module, passive wiring interface for SNB10D I/O marshalling.

Communication & Network Modules

• SCU11D: Vnet/IP communication unit, dual-port Ethernet, primary safety network interface for SNB10D nodes.
• SCU21D: Redundant Vnet/IP communication unit, hot-standby network failover for critical SIS loops.
• IGU610: Integrated Gateway Unit, ProSafe-RS to CENTUM VP DCS integration, OPC-UA data bridge.

Power Supply Modules

• SPW481: 48 VDC power supply module, redundant configuration support, for SNB10D node power rail.
• SPW241: 24 VDC power supply module, field node power distribution, UPS-compatible input range.

Sourcing Hard-to-Find & Obsolete ProSafe-RS SNB10D Parts

The ProSafe-RS SNB10D platform has been in service for over 15 years across thousands of SIS loops globally. As the system matures, procurement teams face increasing difficulty sourcing specific hardware revisions, particularly early-generation CU1N CPU boards, legacy terminal boards, and discontinued I/O modules that are no longer listed in Yokogawa's active catalog.

Quality Control for the ProSafe-RS SNB10D Range

The SNB10D Safety Node Unit incorporates a complex backplane bus architecture with dedicated safety and diagnostic communication channels. Standard functional testing procedures are insufficient for validating the integrity of these modules prior to redeployment. DriveKNMS applies a multi-stage quality control protocol specifically developed for ProSafe-RS hardware:

• Visual Inspection: Component-level examination for capacitor degradation, PCB trace damage, connector pin integrity, and conformal coating condition.
• Power-On Diagnostics: Module is energized within a ProSafe-RS test rack. Internal self-test routines (CPU watchdog, memory checksum, I/O channel continuity) are executed and logged.
• Vnet/IP Communication Test: Node communication is verified over a live Vnet/IP segment to confirm packet integrity, node addressing, and redundancy switchover behavior.
• I/O Channel Verification: Each analog and digital channel is stimulated with calibrated signals. Response accuracy is measured against Yokogawa factory specifications.
• SIL Diagnostic Coverage Check: Diagnostic coverage metrics are validated against IEC 61508 requirements for the specific module type and hardware revision.
• Burn-In Test: Modules are operated under load for a minimum of 48 hours to screen for early-life failures prior to shipment.