SB401-50

The Yokogawa SB401-50 is an ESB Bus Interface Slave Module designed to provide a slave-side interface for communication over the ESB bus in a Yokogawa control system. The supplied ordering information identifies it as the standard type without explosion protection, with the basic configuration suffix. Its exact configuration should be checked against the complete model number when selecting a replacement.

Model Identification

The SB401 is identified as an ESB Bus Interface Slave Module. The complete ordering code SB401-50 consists of the base model SB401 and two suffix elements:

• -5: Standard type without explosion protection.
• 0: Basic type.

Both suffix elements should be retained when identifying or ordering this module.

Function in the FIO Node Unit

The SB401 provides the ESB bus interface on the node-unit side. It enables communication between the ESB Bus Node Unit and the Field Control Unit through the corresponding ESB Bus Coupler Module.

The module is part of the FIO node configuration, where bus interface modules, power supply modules and I/O modules are installed in the node unit.

Redundant Configuration

For a dual-redundant ESB bus configuration, two SB401 modules are installed in the node unit. This arrangement provides two bus interface paths rather than relying on a single interface module. The required configuration depends on the node-unit type and system architecture.

Technical Specifications

Parameter	Specification
Model	SB401-50
Brand	Yokogawa
Product Type	ESB Bus Interface Slave Module
Base Model	SB401
Suffix -5	Standard type, no explosion protection
Suffix 0	Basic type
Bus Interface	ESB Bus
Configuration	Single or dual-redundant, depending on system configuration

Frequently Asked Questions

Q: What is the function of the Yokogawa SB401-50?

A: It provides the ESB bus interface for an FIO node unit, enabling communication with the Field Control Unit through the ESB Bus Coupler Module.

Q: Can the SB401-50 be used in a redundant configuration?

A: Yes. A dual-redundant ESB bus configuration uses two SB401 modules in the node unit. The corresponding node-unit hardware must support this arrangement.

Q: Does SB401-50 have explosion protection?

A: No. The -5 suffix identifies the standard type without explosion protection. It should not be confused with the -E explosion-protection ordering option. 

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