Product Description

The ALF111-S50 is a high-performance Foundation Fieldbus (FF) H1 communication interface designed for Yokogawa Electric Corporation’s CENTUM VP and CS 3000 DCS platforms.

Installed in an FIO node unit, it enables seamless integration of fieldbus-compliant devices—including transmitters, actuators, and positioners—into the plant control architecture. The module supports Control in the Field (CiF), allowing PID loops to be executed at the device level, which reduces central controller load and improves overall system integrity.

The S50 suffix indicates conformal coating per ISA G3 standard, providing protection against corrosive gases and harsh industrial environments typical of refineries and chemical plants.

Technical Specifications

System Application

The ALF111-S50 is primarily installed in FIO node units, communicating with the Field Control Unit (FCU) via the ESB bus. It facilitates:

• Execution of PID loops directly in field devices

• Reduced load on central controllers

• High system reliability and integrity

Professional FAQ

Does the ALF111-S50 provide power to field devices?
No. The module functions as a communication master only. A Fieldbus power supply and proper terminators are required for device power.

Can this module be used redundantly?
Yes. Two ALF111-S50 modules can be installed in a redundant FIO node, ensuring continuous communication if one fails.

What is the maximum cable length per segment?
Up to 1900 meters using Type A shielded twisted-pair cable, including trunk and spur lengths, per FF H1 standards.