Description

Yokogawa SNB10D-445/CU2T Safety Node Unit

The Yokogawa SNB10D-445/CU2T, also cataloged as the SNB10D-445 Safety Node Unit, operates as a dedicated hardware component for high-integrity field I/O communication within ProSafe-RS Safety Instrumented Systems. It executes deterministic signal acquisition, ESB Bus data transmission, and internal power distribution to connected safety I/O modules.

HardwareSpecifications

Parameter	Specification
ModelBrand	Yokogawa SNB10D-445/CU2T
Origin	Japan
ProductType	Safety Node Units
Weight	Approx. 5.9 kg
Dimensions	120 mm (H) × 45 mm (W) × 130 mm (D)
OperatingTemp	−20 degC to +70 degC
StorageTemp	−40 degC to +85 degC
RelativeHumidity	5% to 95% RH (non-condensing)
PowerSupply	Dual-redundant 24 VDC
PowerConsumption	Max 5.5 A / Approx. 8 W
CommunicationInterface	ESB Bus (Ethernet Safety Backbone)
SafetyCompliance	IEC 61508 SIL3
MountingType	19-inch rack mount / DIN rail or panel mount
SupportedIOModules	Up to 8 per node
NetworkExpansion	Up to 13 nodes (SEC402 coupler), up to 9 nodes (SEC401 coupler)
Certifications	CE, UL, CSA, RoHS

Process Control & DCS Integration

• Supports 4-20 mA HART loop protocol for analog signal interfacing.
• Provides channel-to-channel isolation to prevent cross-coupling of analog and digital signals.
• Implements cold junction compensation (CJC) for thermocouple inputs, ensuring precise temperature signal interpretation.
• Compatible with FOUNDATION Fieldbus and Profibus PA networks for deterministic field device communication.

Frequently Asked Questions

Q: Does the SNB10D-445/CU2T support hot-swappable I/O modules?
A: No, the unit requires a powered-down state for safe insertion or removal of I/O modules.

Q: What is the maximum current load per ESB Bus segment?
A: The maximum combined current consumption of connected safety nodes should not exceed the rated 5.5 A input limit per power supply path.

Q: Is firmware upgrade possible without node removal?
A: Firmware upgrades are supported via the ProSafe-RS configuration interface without physical removal, provided the unit is operational and in a controlled maintenance mode.

Field Installation Guidelines

• Mount on a 19-inch rack or panel using M5 screws with insulation bushes; ensure secure grounding.
• Use shielded twisted-pair cables for ESB Bus connections to minimize electromagnetic interference.
• Terminate the last node in the bus line with the integrated /CU2T connector to prevent reflections.
• Maintain ambient operating temperature and humidity within specified ranges; avoid direct sunlight and corrosive exposure beyond ISA G3 tolerance.
• Route power and communication cables separately where possible to reduce crosstalk and maintain signal integrity.

Specifications

• Brand: Yokogawa

Advantages

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