ALF111-S51 Yokogawa CENTUM VP FOUNDATION Fieldbus Module

Availability: 10 left in stock

Yokogawa ALF111-S51 Fieldbus Communication Module The Yokogawa ALF111-S51, also cataloged as the ALF111 FOUNDATION Fieldbus Communication Module, operates as a...

SKU: ALF111-S51

Manufacturer: Yokogawa
Product No.: ALF111-S51
Product Type: Communication Modules
Product Origin: JAPAN
Payment:T/T, Western Union
Weight: 400g
Shipping port: Xiamen
Warranty: 12 months

Description Reviews

Yokogawa ALF111-S51 Fieldbus Communication Module

The Yokogawa ALF111-S51, also cataloged as the ALF111 FOUNDATION Fieldbus Communication Module, operates as a dedicated hardware component for digital communication interface for FF H1 devices within Yokogawa CENTUM VP control platforms.

Suffix Breakdown & Model Matrix

The complete catalog number ALF111-S51 represents a specific hardware configuration defined by its suffix string:

ALF111: Base model code for FOUNDATION Fieldbus H1 communication module.
-S: Standard performance execution layout.
5: Non-explosion proof rating option.
1: Conformal coating meeting ISA Standard G3 environmental resistance requirements.

Hardware Specifications

Parameter	Specification
Model	ALF111-S51
Brand	Yokogawa
Origin	Japan
Weight	0.40 kg
Dimensions	Compact modular rack-slot format
Operating Temp	-20 to +55 deg C
Power Consumption	< 6 W
Communication Protocol	FOUNDATION Fieldbus H1
Transmission Rate	31.25 kbps
Field Device Capacity	Up to 32 devices per segment
Electrical Isolation	Complete bus-to-system isolation
Power Supply	24 VDC backplane powered

DCS Process Control & FOUNDATION Fieldbus Protocol Execution

The ALF111-S51 card establishes deterministic link communication across FOUNDATION Fieldbus H1 network segments while maintaining isolated signal integrity across system backplanes. Integrated Link Active Scheduler (LAS) logic controls bus token passing and execution timing loops for connected field instruments. Furthermore, the module handles digital telemetry streams and 4-20 mA HART loop protocol translation routines while maintaining channel-to-channel isolation. Internal software algorithms continuously perform cold junction compensation (CJC) processing for connected remote thermal transmitters to eliminate noise drift on primary control loops.

Frequently Asked Questions

Q: Can maintenance teams hot-swap the ALF111-S51 module inside an active Field Control Station slot?

A: Personnel can extract and replace the module during powered operation only when the target rack incorporates a dual-redundant ALF111 communication card pair.

Q: How does the ISA Standard G3 conformal coating option protect internal module circuitry?

A: The G3-rated protective layer prevents atmospheric hydrogen sulfide and chlorine gas contaminants from corroding internal copper traces and solder points.

Q: Does removing the active Link Active Scheduler module cause total communication failure on the field segment?

A: A backup LAS device on the fieldbus segment assumes bus scheduling duties automatically when the primary ALF111-S51 module disconnects.

Field Installation Guidelines

Insert the card straight into the designated rack slot until the upper and lower locking levers click completely into place.
Terminate both ends of the FOUNDATION Fieldbus H1 segment with approved RC network bus terminators to maintain 100 ohm characteristic impedance.
Attach field wiring shield drain conductors directly to the dedicated instrumentation ground bus bar rather than the module frame ground.
Maintain a minimum clearance of 50 mm above and below the card housing to facilitate natural vertical convection cooling.
Segregate FOUNDATION Fieldbus H1 twisted-pair cables from high-voltage AC lines in separate cable trays to prevent inductive noise coupling.

What's clients say about us

Excellent Emergency Support!

Our production line was down due to a faulty Bently Nevada monitor. We found it in stock here and they shipped it via DHL immediately. Back in operation within 48 hours—truly a lifesaver for our plant.

Mark Thompson

Maintenance Manager, USA

Reliable Source for New Spares

Finding brand new, original modules is critical for our safety. This team delivers factory-fresh components with full certification. Their commitment to only selling new products makes them our most trusted partner.

Robert Hoffmann

Engineering Lead, Germany

Top-tier Service and Quality

We have sourced Honeywell and Schneider parts here for two years. Every shipment arrives well-packaged with original factory seals intact. Clear communication and the best lead times in the industry.