NFBU200-015

The Yokogawa NFBU200-015 is a long-format base module designed to provide the mechanical mounting structure and internal bus connections for a modular FCN control unit. It accommodates CPU, power supply, I/O, and extension-related modules within the controller assembly. The NFBU200 platform provides 10 function-module slots, two power supply slots, and a duplex SB bus for internal module communication.

Functional Description

The NFBU200 serves as the chassis and internal connection platform for the controller. It provides the mounting positions and electrical backplane connections required to assemble a control unit or extension unit from compatible function modules.

Its internal SB bus distributes communication between installed modules. Depending on the system configuration, the base module can accommodate CPU modules, power supply modules, I/O modules, and SB bus repeat or E2 bus interface modules.

Module Configuration

The NFBU200 long base module provides the following configuration:

• 10 function-module slots for CPU, I/O, and extension-related modules.
• 2 power supply module slots, allowing a duplex power supply arrangement with supported power supply modules.
• Duplex SB bus, providing the internal communication path between installed modules.
• Support for use as either a control unit or an extension unit, subject to the installed modules and system configuration.
• CPU module installation occupies two function-module slots.

The available I/O capacity depends on whether the unit operates independently or uses extension modules. Slot allocation must account for the CPU and any required bus interface or repeat modules.

Technical Specifications

Parameter	Specification
Model	NFBU200-015
Brand	Yokogawa
Product Type	Long Base Module
Module Architecture	Modular controller base
Function Module Slots	10
Power Supply Slots	2
Internal Bus	Duplex SB bus
Maximum Self-Consumption	0.4 A at 5 V DC
Power Supply Configuration	Single or duplex, subject to compatible modules

Installation and Configuration Notes

The NFBU200 family has rack-mounted and DIN rail-mounted versions. The mounting arrangement must be verified against the complete manufacturer ordering code before installation.

The base module also provides configuration settings for unit numbering and CPU duplex operation. These settings determine how the base module is assigned within the controller architecture and how CPU modules are configured.

Unused slots require the appropriate dummy covers. Yokogawa identifies NFDCV01 for I/O module slots and NFDCV02 for power supply module slots.

Frequently Asked Questions

Q: How many I/O modules can the NFBU200 accommodate?

A: The base module has 10 function-module slots. However, the actual I/O module capacity is lower because CPU modules and extension-related modules also occupy slots. A standalone control unit can accommodate up to 8 I/O modules in the applicable standard configuration.

Q: Does the NFBU200 support redundant power supplies?

A: Yes. It has two power supply module slots and supports a duplex power supply configuration. Yokogawa specifies that the NFPW444 power supply module is the supported model for redundancy in the relevant NFBU200 configuration.

Q: What should be checked when replacing an NFBU200-015?

A: Verify the complete ordering code, mounting arrangement, bus configuration, and installed CPU and power supply modules. The supplied designation NFBU200-015 does not directly establish all the suffix details in Yokogawa's published ordering-code tables, so the original nameplate should be checked before selecting a replacement.

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