The Yokogawa SNB10D‑425/CU2T is a rack‑mountable Safety Node Unit designed for industrial Safety Instrumented Systems (SIS), most commonly used in Yokogawa’s

ProSafe‑RS safety platform. It acts as a central interface for safety I/O and field sensors/actuators in high‑integrity safety applications such

as emergency shutdown (ESD), HIPPS (High‑Integrity Pressure Protection Systems), and

other critical process protection systems.

Frequently Asked Questions

Q1. What is the SNB10D‑425/CU2T Safety Node Unit?
A: It’s a modular safety node used in safety instrumented systems that interfaces field inputs/outputs (sensors and actuators) with a safety control system via

the ESB bus, while providing redundancy and high integrity for critical safety logic execution.

Q2. What does the model code mean?
A:

• SNB10D: Safety node series, duplexed architecture (dual redundant power and bus modules).
• 425: Designates the integrated safety I/O configuration (e.g., an allocation of analog/digital I/O — the exact mix is model‑specific).
• /CU2T: Connector unit with ESB bus terminator (Part No. S9343FA), ensuring proper ESB interface termination.

Q3. What is the ESB bus and why is it important?
A: The Extended Safety Bus (ESB) is a dedicated high‑integrity communication link in Yokogawa’s SIS used to connect

safety node units with safety controllers and other nodes. The termination provided by the CU2T option

ensures signal integrity and proper electrical characteristics for the bus.