Product Description
The ALF111-S51 is a high-performance FOUNDATION™ Fieldbus (FF) H1 communication interface module designed for the Yokogawa CENTUM VP and Yokogawa CENTUM CS 3000 control systems. It acts as the gateway between the Field Control Unit (FCU) and H1 fieldbus segments, enabling bidirectional digital communication with smart field devices such as valve positioners, flowmeters, and pressure transmitters.
By integrating the ALF111-S51, users can deploy Control in the Field (CIF) strategies, distributing control functions directly to field instruments and significantly reducing central controller processing load.
This S51 standard variant includes conformal coating compliant with ISA-S71.04 Severity Level G3, providing enhanced protection against corrosive gases such as hydrogen sulfide and chlorine. It is particularly suited for harsh chemical, petrochemical, and wastewater treatment environments.
Technical Specifications
| Parameter | Specification |
|---|---|
| Module Type | FOUNDATION Fieldbus H1 Interface |
| Communication Channels | 4 H1 segments per module |
| Physical Layer | ISO/IEC 61158-2 compliant (31.25 kbps) |
| Device Capacity | Up to 32 devices per module (max. 8 per segment) |
| Protection Class | Standard type (S), Non-explosion protected (5) |
| Environmental Rating | ISA-S71.04 G3 conformal coating |
| Control Functions | Supports Link Active Scheduler (LAS) and CIF |
| Current Consumption | 0.5 A at 5 V DC |
| Redundancy | Dual-redundant configuration supported |
| Fieldbus Power | External power supply and terminators required |
| Operating Temperature | 0°C to 55°C |
| Weight | 0.4 kg |
Application
The ALF111-S51 is widely used in:
-
Oil & gas refineries
-
Sulfur recovery and wastewater treatment plants
-
Large-scale pharmaceutical batch processing
-
Offshore production platforms
It is ideal for plants migrating from traditional 4–20 mA analog loops to fully digital FOUNDATION Fieldbus networks, enabling enhanced diagnostics, reduced wiring, and distributed control capability.
Technical FAQ
Does the ALF111-S51 provide power to the fieldbus segment?
No. The module manages communication only. A separate fieldbus power conditioner and proper segment terminators are required to supply power and maintain impedance on the H1 network.
What is the benefit of the G3 option?
The “1” designation indicates compliance with ISA-S71.04 Severity Level G3. This ensures internal circuitry is protected against corrosive atmospheric contaminants, extending module lifespan in chemically aggressive environments.
| Quick Quotes | Receive price & availability FAST from our dedicated customer service team. |
|---|---|
| Delivery | Expedited, Freight, And International Shipping Available. |
| Condition | 100% New with Original Package |
| Payment | We accept American Express, Discover, MasterCard, PayPal, and Visa. Our site is secured by RapidSSL. |
| Shipping Port | ShangHai, Xiamen |
| Warranty | 12 Months |
| Q: Is Our Pricing Competitive? |
| A: Yes, we collaborate with over 50 countries worldwide. As a top supplier in China, we offer significant discounts based on market trends. |
| Q: What Is the Warranty Period? |
| A: All our new and original products come with a standard one-year warranty. |
| Q: What Payment Methods Do We Accept? |
| A: We require 100% T/T (Telegraphic Transfer) payment before shipping. For items with a lead time, a 30% deposit is needed upfront, and the remaining 70% is due before shipping. If you have a representative in China, you can arrange an RMB transfer through them. |
| Q: What Shipping Methods Do We Use? |
| A: We primarily use FedEx, DHL, UPS, and BRE for shipping. If you have an account with any of these carriers, you can handle shipping directly. We also offer free shipping to China-based freight forwarders. |
| Q: What Is Our Delivery Time? |
| A: Delivery usually takes 1-3 days after receiving the initial payment. For items with a lead time, shipping will occur according to the specified schedule. |
| Q: How Do We Package the Goods? |
| A: We ensure safe packaging with multiple layers of protection. Products are first placed in their original boxes and sealed with labels. A layer of bubble wrap is then added for collision protection during transit. Finally, the items are packed securely in durable boxes. |
| Q: How Can Customers Contact Us and Request a Quote? |
| A: You can reach out to us via email, WhatsApp, WeChat, Skype, or your preferred communication platform. Contact us with your needs, and we'll provide a prompt, customized quote. |
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