Description

Yokogawa SNB10D-425/CU2T Safety Node Unit

The Yokogawa SNB10D-425/CU2T, also cataloged as the SNB10D-425 Safety Node Unit, operates as a dedicated hardware component for transmitting analog input and contact signals to the Safety Control Unit within ProSafe-RS systems. It integrates dual-redundant power modules and ESB bus interfaces to maintain continuous data and power flow for safety I/O modules.

Hardware Specifications

Parameter	Specification
Model Brand	Yokogawa
Origin	Japan
Weight	5.9 kg (without I/O modules)
Dimensions	482.6 mm (W) x 221.5 mm (H) x 205.0 mm (D)
Operating Temp	-20 degC to +70 degC
Power Consumption	100-120 VAC: 200 VA220-240 VAC: 230 VA24 VDC: 5.5 A
Power Supply	Dual-redundant, AC 100-120 V / 220-240 V, 24 VDC
Communication Interface	ESB Bus with /CU2T Connector Unit (Part No: S9343FA)
Max Safety Node Units	13 (with SEC402) / 9 (with SEC401)
I/O Module Compatibility	Safety-certified analog and discrete I/O modules
Bus Cable	Yokogawa YCB301 (≥ 1 m)
Conformal Coating	ISA Standard G3

Process Control Features

The SNB10D-425/CU2T provides channel-to-channel isolation to prevent signal interference between analog inputs and contact signals. It supports 4-20 mA HART loop protocols for analog process instrumentation and ensures cold junction compensation (CJc) for thermocouple inputs. The ESB bus interface maintains synchronized communication with the ProSafe-RS Safety Control Unit, with galvanic isolation between power and signal paths.

Frequently Asked Questions

Q: What is the maximum number of SNB10D-425/CU2T units per safety control system?
A: Up to 13 units with SEC402 ESB coupler modules, and up to 9 units with SEC401 modules.

Q: Can I hot-swap I/O modules inside this unit?
A: Modules can be replaced only under powered-down conditions to maintain SIL3 compliance; hot-swap is not supported.

Q: What type of cables are required for ESB bus communication?
A: Standard Yokogawa YCB301 ESB bus cables of 1 m or longer are required.

Field Installation Guidelines

• Install inside a keyed, grounded industrial metallic cabinet to meet EMC and safety requirements.
• Seal unused I/O slots with SDCV01 dummy covers to prevent dust entry and thermal unevenness.
• Maintain correct ESB bus termination using the /CU2T connector unit; do not add external terminators.
• Route power and signal cables separately to reduce interference; ensure minimum bend radius and secure fastening.
• Ground chassis and metallic parts to the plant grounding system to prevent electrical noise propagation.

Specifications

• Brand: Yokogawa

Advantages

• High reliability in industrial environments
• Supports continuous operation
• Compatible with major PLC/DCS systems