Yokogawa AFS10D Control Units

The Yokogawa AFS10D serves as the primary AFS10D Duplexed Field Control Unit utilized to execute dual-processor synchronization and deterministic process control loops across Yokogawa Vnet/RIO platforms.

Hardware Specifications

Process Control and Distributed Control Architecture

• Real-Time Processor Mirroring and Failover The hardware architecture integrates two synchronized control processors running in a continuous parallel tracking mode. If the active processor encounters a diagnostic fault or memory parity error, execution transfers instantly to the hot-standby unit, ensuring a bumpless transfer that maintains uninterrupted process control and zero downtime for critical loops.
• Function-Expanded Capacity for Remote I/O Engineered as an expanded-capacity model, the device features enlarged volatile and non-volatile memory registers. This expanded memory architecture provides the computational throughput required to execute complex control algorithms and manage high-density Remote I/O (RIO) nodes across large-scale plant networks without degradation of the deterministic control cycle.
• Dual-Source Power Isolation and Protection The power subsystem accepts a wide electrical envelope spanning multiple AC and DC configurations, including 24 V DC battery-backed systems. Dual isolated power rails feed the processing cores through an integrated 8 A / 250 V circuit breaker, preventing common-mode voltage surges from compromising channel-to-channel isolation limits.

Frequently Asked Questions

Q: How does the AFS10D chassis execute data synchronization across the Vnet/RIO interface?

A: The duplexed processor cards exchange internal register states and memory maps via a high-speed, dedicated bus layer on the passive backplane. This synchronization loop ensures that the hot-standby processor holds identical I/O images and step-sequence data, enabling an immediate failover if the primary processor stops responding.

Q: Can the internal 8 A overcurrent protection fuse be replaced while the field control unit is online?

A: No. Replacing the main power line protection fuse or resetting the built-in breaker requires isolating the input power source. To prevent electrical shock or uncommanded system reboots, power down the specific side of the redundant power supply network before servicing the fuse assembly.