Brand: Yokogawa

Yokogawa Node Interface Unit for CENTUM VP DCS (YS/AZD Reference)

Name: Yokogawa Node Interface Unit CENTUM VP – Datasheet & Quote
Brand: Yokogawa

Description

Overview: The Communication Bridge Between Controller and Field I/O

The Yokogawa Node Interface Unit (NIU) is a core hardware component of the Yokogawa CENTUM VP integrated production control system, providing the interface function that allows a Field Control Unit (FCU) to communicate with N-IO or FIO field input/output units, and allowing multiple node interface units to communicate with one another across the plant control network. Beyond communication, the NIU also supplies power to its connected I/O units, making it a central building block of every distributed I/O node in a CENTUM VP architecture.

As a trusted supplier of Yokogawa control system components, Seven Star LLC sources and supplies Yokogawa Node Interface Units to refineries, petrochemical plants, and process facilities across Oman and the wider GCC operating CENTUM VP distributed control systems. Because DCS node hardware must match the exact system release and I/O configuration in service, Seven Star LLC helps plant engineering teams confirm the correct suffix code and configuration for their existing CENTUM VP installation.

Working Principle: Distributed I/O Node Architecture

An N-IO node in the CENTUM VP architecture consists of a Node Interface Unit together with N-IO I/O units, communicating I/O signals to and from field devices with a Field Control Unit via an N-ESB bus or a dual-redundant optical ESB bus. A single Node Interface Unit can connect up to six N-IO I/O units, with the F-SB bus cable for inter-unit communication and the power supply cable for the base plate selected to match the number of connected I/O units. This modular node structure allows a CENTUM VP system to scale its field I/O capacity by adding nodes rather than requiring a single monolithic I/O rack.

The Node Interface Unit itself incorporates redundant power supply units and N-ESB bus modules in its dual-redundant configuration, ensuring that a single power supply or communication module failure does not interrupt the flow of process I/O data between the field and the controller. This redundancy, combined with the NIU’s role as the power source for its connected barrier or I/O base plates, makes it one of the most critical single points in the distributed I/O chain, and a component that plant maintenance teams monitor closely for early signs of degradation.

Engineering Design of the Node Interface Unit

The Node Interface Unit is available in DIN-rail mountable and wall-mountable configurations, with a full model and suffix code system covering redundancy level, power supply input type (100-240 V AC or 24 V DC), uplink and downlink bus type (N-ESB or optical ESB at various distance ranges), explosion protection option, and ambient temperature rating (standard 0 to 60°C, or extended -40 to 70°C with the temperature environment option). Power consumption is approximately 190 VA for AC-input units or 150 W for DC-input units, with a maximum configuration weight of approximately 4.2 kg.

For hazardous-area installations, the NIU supports an explosion protection option code, and when combined with parent products carrying the /ATDOC option, the unit can be configured to meet applicable explosion protection directives. Base plates for barriers (compatible with MTL or P+F barrier types) connect to the Node Interface Unit via a dedicated F-SB bus cable, extending the NIU’s field signal interface capability to intrinsically safe circuits where required.

Key Features

The Yokogawa Node Interface Unit provides the critical communication and power backbone for CENTUM VP distributed I/O nodes. Key characteristics include:

Interface function connecting a Field Control Unit to N-IO/FIO field I/O units via N-ESB or optical ESB bus.
Supports up to 6 I/O units per Node Interface Unit.
Supplies power directly to connected I/O and barrier base plates.
Dual-redundant power supply and bus module configuration options for high availability.
DIN-rail or wall-mountable installation.
Standard (0 to 60°C) or extended temperature environment (-40 to 70°C) options.
Optional explosion protection for hazardous-area field I/O nodes.

Industrial Applications

The Node Interface Unit is deployed wherever a Yokogawa CENTUM VP distributed control system requires field-mounted or remote I/O nodes, including refinery process units, petrochemical plants, and oil and gas production facilities where field I/O must be located close to the process rather than centralized in a single control room rack. Its dual-redundant configuration options and wide temperature ratings support both standard control room installations and harsher field-mounted enclosure locations.

Seven Star LLC supports refinery instrumentation teams, petrochemical maintenance departments, and DCS system integrators across Oman, Muscat, Sohar, and the broader GCC region with sourcing of Yokogawa CENTUM VP node hardware, helping plants maintain distributed I/O availability and plan system expansions.

Technical Specifications

The table below summarizes the core specifications of the Yokogawa Node Interface Unit as supplied by Seven Star LLC.

Parameter	Specification
Model	Yokogawa Node Interface Unit (A2NN30D and related CENTUM VP node models)
Function	Communication interface between FCU and N-IO/FIO field I/O units, plus power supply to I/O units
I/O Unit Connections	Up to 6 per NIU
Mounting	DIN-rail or wall-mountable
Power Consumption	Approx. 190 VA (AC input) or 150 W (DC input)
Weight	Approx. 4.2 kg (max. configuration)
Ambient Temperature	0 to 60°C standard; -40 to 70°C with temperature environment option
Explosion Protection	Optional, via suffix code and /ATDOC parent product option
Target Platform	Yokogawa CENTUM VP Integrated Production Control System

Request a Quote for Yokogawa Node Interface Unit for CENTUM VP DCS (YS/AZD Reference)

Seven Star LLC supplies the Yokogawa Node Interface Unit with datasheet documentation and regional technical support. Contact our instrumentation and control systems division for a formal B2B quotation, to confirm the correct suffix code and configuration for your existing CENTUM VP installation, or to obtain the complete technical datasheet.Seven Star LLC supplies this item on request with the manufacturer documentation, and availability and lead time are confirmed at quotation.

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About brand

Yokogawa is the Japanese measurement and industrial automation company behind the DPharp EJA and EJX pressure transmitters, CENTUM distributed control systems and ProSafe-RS safety systems. Tamisuke Yokogawa set it up in 1915 as an electric meter research institute in Shibuya, Tokyo. It began selling electric meters in 1917, was incorporated as Yokogawa Electric Works in 1920, and has been Yokogawa Electric Corporation since 1986. In 1975 it released CENTUM, which it describes as the world's first distributed control system.

Seven Star LLC is an independent supplier in Muscat. We list Yokogawa transmitters, flowmeters, analysers, controllers, recorders and CENTUM and ProSafe spare modules, and supply them to oil and gas, power, water and process plants in Oman and the GCC by model code.

Yokogawa at a glance

Established	1915, Shibuya, Tokyo, by Tamisuke Yokogawa with Ichiro Yokogawa and Shin Aoki
Milestones	Electric meters from 1917; incorporated in 1920; CENTUM DCS in 1975; renamed Yokogawa Electric Corporation in 1986
Headquarters	Tokyo, Japan
Product families	Pressure and temperature transmitters, magnetic, vortex and Coriolis flowmeters, liquid and gas analysers, controllers and recorders, CENTUM VP DCS, ProSafe-RS safety systems and STARDOM controllers

Yokogawa products we list

Family	Models	Typical use
Pressure and DP transmitters	EJA110E, EJA430E, EJA530E, EJX110A, EJX530A, EJX910A multivariable	Pressure, level and DP flow measurement in process plants
Temperature transmitters	YTA610, YTA710	RTD and thermocouple signals converted to 4-20 mA, HART or fieldbus
Flowmeters	ADMAG AXG, ADMAG AXW, ROTAMASS TI, VY vortex, VF701	Water and conductive liquids, mass flow of hydrocarbons, steam and gas
Analysers	TDLS8000 laser gas analyser, FLXA402, FLXA21 DO, E7042UD zirconia cell, K9471DS cover	Combustion O2, in-situ gas analysis, pH, conductivity and dissolved oxygen
Controllers and recorders	UT35A/UT32A, UT32A-D, UT55A/UT52A, UT75A, UP35A/UP32A, UP55A, YS1700, GX10/GX20, GP10/GP20, GM10, µR20000	Single-loop control, furnace programs and data recording
Control and safety systems	CP451-10 processor, ADV161, ADV551, node interface unit, ProSafe-RS, ProSafe-RS Lite, ProSafe-SLS, FCN-500	Spares and expansions for CENTUM DCS, safety systems and STARDOM
Battery packs	S9129FA, S9185FA, S9548FA	Memory backup batteries for DCS and controller modules

The EJA and EJX transmitters use Yokogawa's DPharp sensor: two silicon resonators whose vibration frequency changes with pressure, so the output is a digital frequency rather than an analogue strain signal. The model code describes the instrument completely. In EJA110E, "110" is a differential pressure transmitter, and the letters after the dash set the span, wetted materials, process connection, electrical output and approvals. When you replace a transmitter, sending the full code from the nameplate avoids a mismatch in range or materials.

Where Yokogawa products are used

In Oman and the GCC, Yokogawa transmitters, analysers and control systems are found in oil and gas production, gas processing and LNG, refineries and petrochemical plants, power and desalination stations, and water treatment. Many plants still run CENTUM CS 3000 and CENTUM VP systems that need spare I/O modules and batteries.

Ordering Yokogawa products: what we need

Send the full model and suffix code from the nameplate (for example EJA110E-JMS5J-912NN/KF22) and the style code. For DCS modules, add the module type and system version. For analysers, send the sensor type, measuring range and process conditions.

Facts checked against Yokogawa's corporate history, October 2026.

Browse Yokogawa products by category: PLC & I/O Cards, Flowmeters, Pressure Instrumentation, Automation Accessories, Temperature Instrumentation.

FAQ

Questions about the Yokogawa Node Interface Unit for CENTUM VP DCS

Answers from our engineering team on installation, compatibility and integration.

01What does the Node Interface Unit do in a CENTUM VP system?

It provides the communication interface between a Field Control Unit and N-IO or FIO field I/O units, and supplies power to the connected I/O and barrier base plates.

02How many I/O units can one Node Interface Unit support?

A single Node Interface Unit can connect up to 6 N-IO I/O units.

03What mounting options are available?

The Node Interface Unit is available in DIN-rail mountable and wall-mountable configurations to suit different cabinet and field enclosure layouts.

04Is the Node Interface Unit available for hazardous areas?

Yes, an explosion protection suffix code option is available, and the unit can be configured to meet applicable directives when combined with compatible parent products.

05Does Seven Star LLC supply this part across the GCC?

Yes, Seven Star LLC sources and supplies Yokogawa CENTUM VP Node Interface Units to refinery, petrochemical, and process industry customers across Oman and the wider GCC region.