Yokogawa AFS20S Field Control Unit

The Yokogawa AFS20S Field Control Unit is a powerful, compact, and highly reliable component in Yokogawa’s CENTUM VP distributed control system (DCS) platform. Designed to deliver real-time control and monitoring in large-scale industrial processes, the AFS20S serves as a critical unit that executes control logic, manages field I/O, and communicates with supervisory systems.

This unit integrates advanced hardware performance with high-speed processing capabilities, offering users fast response times and uninterrupted data processing. It supports dual-redundancy configurations, hot-swapping, and features Yokogawa’s proven pair & spare architecture, ensuring high availability in mission-critical environments. With flexible scalability and tight integration with other CENTUM VP components, the AFS20S is ideally suited for oil & gas, petrochemical, power, and water treatment facilities.

Product Specifications

Applications

The Yokogawa AFS20S is deployed in diverse industrial sectors where real-time process control, high reliability, and safety compliance are paramount. Typical applications include:

• Oil & Gas: Used for control of upstream, midstream, and downstream operations including refineries.

• Chemical and Petrochemical Plants: For batch and continuous processing.

• Power Generation: Applied in thermal, hydro, and nuclear control systems.

• Water & Wastewater Treatment: Supports SCADA and DCS-based automation.

• Pulp & Paper: For distributed automation of paper machines and chemical recovery.

• Pharmaceutical Manufacturing: Ensures precision and repeatability for GMP compliance.

• Metals and Mining: Used in process automation and control of smelting and refining.

Product Advantages

• High Availability Architecture: The Pair & Spare configuration ensures continuous operation even if one processor fails.

• Hot Swap Capabilities: Modules can be replaced during operation without system shutdown, reducing downtime.

• Flexible and Scalable: Can easily be integrated into small to large-scale systems with thousands of control loops.

• Fast Control Cycle: Supports rapid loop updates for time-sensitive process control.

• Fieldbus and Ethernet Ready: Seamless communication with smart field instruments via FOUNDATION™ Fieldbus or Ethernet/IP.

• Long Lifecycle Support: Yokogawa’s DCS systems are known for long-term availability and backward compatibility.

• Efficient Power Usage: Low power design minimizes heat and energy consumption.

• Robust Design: Operates reliably under a wide range of environmental conditions with industrial-grade protection.

Frequently Asked Questions (FAQ)

1. What is the main function of the AFS20S in a CENTUM VP system?

   The AFS20S functions as the field control unit that executes control strategies and interfaces with I/O modules in real-time.

2. Does the AFS20S support redundant CPUs?

   Yes, it features dual-redundant CPUs operating in a Pair & Spare configuration for fault tolerance.

3. How many control loops can a single AFS20S manage?

   It can handle up to 2,000 PID control loops depending on configuration and system design.

4. Can modules be replaced while the system is running?

   Yes, the AFS20S supports hot-swapping of CPU and I/O modules without interrupting the control process.

5. Is the AFS20S compatible with legacy Yokogawa systems?

   It is compatible with CENTUM VP systems and supports integration with previous CENTUM CS systems with proper configuration.

6. What type of I/O connections does the AFS20S support?

   It supports both direct Field I/O (FIO) and remote I/O through Ethernet-based connections or ESB bus.

7. What environments is the AFS20S certified for?

   It is certified for use in hazardous environments with approvals including ATEX, IECEx, UL, and CSA.

8. What is the typical lifespan of the AFS20S?

   Yokogawa offers support and parts for up to 15–20 years, ensuring long-term system sustainability.

9. How is communication handled in the AFS20S?

   It uses Vnet/IP, a 1 Gbps real-time network for high-speed and reliable communication within the control system.

10. Can the AFS20S be used in safety instrumented systems (SIS)?

    While the AFS20S itself is not SIL-certified, it can operate in parallel with Yokogawa’s ProSafe-RS system for safety integration.