The Yokogawa AFS10D Duplexed Field Control Unit (FCU) is a redundant controller designed for CENTUM CS 3000 and early CENTUM VP Distributed Control Systems using the RIO (Remote I/O) architecture. The AFS10D serves as the processor of a Field Control Station (FCS), providing redundant CPU operation, automatic processor switchover, and reliable process control for mission-critical industrial applications. Proper installation, wiring, grounding, and commissioning are essential to ensure stable controller operation and maximum system availability. The AFS10D features a 16 MB main memory, battery-backed memory retention, and redundant controller architecture for high availability.

Contents

• 1. AFS10D Field Control Unit Overview
• 2. Technical Features
• 3. Typical Industrial Applications
• 4. Installation Planning
• 5. Hardware Inspection
• 6. Installation Environment
• 7. Rack Mounting Procedure
• 8. Power Supply Connections
• 9. RIO Communication Connections
• 10. Grounding Requirements
• 11. Commissioning Procedure
• 12. Functional Testing
• 13. Preventive Maintenance
• 14. Practical Installation Case
• 15. Frequently Asked Questions

AFS10D Field Control Unit Overview

The AFS10D is a duplexed Field Control Unit designed for 19-inch rack installation in RIO-based Field Control Stations. Two processor modules operate in parallel, allowing automatic switchover if the active processor fails. The controller communicates with Remote I/O nodes through the RIO bus while exchanging plant data with operator stations over the control network. The hardware incorporates battery-backed memory that preserves controller data during short-term power interruptions.

Technical Features

• Duplexed processor architecture
• Automatic controller switchover
• 16 MB main memory
• Battery-backed memory protection
• RIO communication support
• 19-inch rack-mount design
• Continuous processor synchronization

Typical Industrial Applications

• Oil and gas processing facilities
• Petrochemical plants
• Chemical production units
• Power generation stations
• Water treatment plants
• Continuous manufacturing processes

Installation Planning

• Review engineering drawings
• Verify rack dimensions
• Confirm power source availability
• Review RIO network topology
• Prepare controller configuration files

Hardware Inspection

• Verify model identification
• Inspect controller modules
• Check communication interfaces
• Inspect terminal connections
• Verify mounting hardware

Installation Environment

• Maintain adequate cabinet ventilation
• Avoid excessive humidity
• Minimize vibration
• Prevent dust accumulation
• Maintain recommended ambient temperature

Rack Mounting Procedure

1. Disconnect all power sources.
2. Install the FCU into the designated rack position.
3. Secure mounting screws.
4. Install both processor modules.
5. Verify module seating.
6. Inspect cable routing before energizing the system.

Power Supply Connections

• Connect redundant power supplies.
• Verify supply voltage.
• Inspect protective devices.
• Confirm terminal tightness.
• Verify power indicators after energization.

RIO Communication Connections

• Connect the RIO communication bus.
• Verify cable polarity and routing.
• Inspect communication connectors.
• Confirm node addressing.
• Label all communication cables.

Grounding Requirements

• Connect protective earth conductors.
• Verify cabinet grounding.
• Maintain low grounding resistance.
• Avoid ground loops.
• Inspect grounding continuity.

Commissioning Procedure

VERIFY INSTALLATION
CONNECT POWER
VERIFY RIO NETWORK
CHECK GROUNDING
POWER UP BOTH CONTROLLERS
VERIFY SYNCHRONIZATION
DOWNLOAD APPLICATION
VERIFY SYSTEM STATUS

Functional Testing

• Verify active controller operation.
• Confirm standby controller synchronization.
• Test automatic processor switchover.
• Verify RIO communication.
• Review controller diagnostics.

Preventive Maintenance

• Inspect communication cables regularly.
• Verify redundancy status.
• Review diagnostic logs.
• Maintain controller backups.
• Inspect cabinet cooling equipment.

Practical Installation Case

During commissioning of a refinery expansion project, engineers observed that the standby controller failed to enter synchronized operation after startup.

Inspection revealed an incorrectly seated processor module that prevented synchronization between the active and standby controllers.

After reseating the module:

• Processor synchronization completed successfully.
• Automatic failover testing passed.
• RIO communication remained stable.
• The Field Control Station entered normal operation.

Frequently Asked Questions

What is the AFS10D?

The AFS10D is a duplexed Field Control Unit for RIO-based CENTUM systems. It provides redundant processing, automatic controller switchover, and battery-backed memory for high system availability.

What type of I/O system does the AFS10D support?

The AFS10D is designed for Remote I/O (RIO) architectures used in earlier CENTUM control systems.

How much memory does the controller provide?

The controller includes 16 MB of main memory with battery backup to preserve data during temporary power loss.

Summary: Proper installation of the Yokogawa AFS10D Duplexed Field Control Unit requires correct rack mounting, redundant power wiring, reliable RIO communication, effective grounding, and thorough commissioning. Following these procedures ensures dependable controller redundancy and long-term process control reliability.