SNB10D-425/CU2T Overview

The Yokogawa Safety Node Unit SNB10D-425/CU2T is a safety node unit with a dual-redundant 220-240V AC power supply and a terminating connector for the ESB bus, designed for reliable I/O interfacing in safety systems.

Application

Safety System Integration: Functions as a remote I/O interface within a ProSafe-RS safety instrumented system (SIS).

Signal Transmission: Collects analog and contact input signals from field devices (e.g., sensors, switches).

Bus Communication: Transmits data to the central safety control unit via the dedicated ESB bus.

Power Distribution: Supplies power to connected FIO (Field I/O) modules.

System Expansion: Used to scale I/O capacity; up to 13 units can connect to a control unit with an SEC402 coupler.

Termination Point: The /CU2T variant provides a terminating connector for the ESB bus segment.

FAQ

Q1: What is the main purpose of this unit?

A1: It is a Safety Node Unit that interfaces field signals with a safety controller via the ESB bus and powers I/O modules.

Q2: What makes its power supply reliable?

A2: It features a dual-redundant 220-240V AC power supply for continuous operation.

Q3: What does the suffix code "-425" specify?

A3: It indicates ISA G3 compliance for harsh environments (-20 to +70°C) without explosion protection.

Q4: What is included with the /CU2T option?

A4: It includes a Connector Unit with a built-in Terminator for the ESB Bus (part S9343FA).

Q5: How is it physically installed?

A5: It is rack-mounted using four M5 screws with provided insulation bushes.