Yokogawa ALF111-S50 Foundation Fieldbus Module 4 Ports
Introduction:
This Yokogawa ALF111-S50 is a FOUNDATION Fieldbus communication module with 4 ports. Features 31.25 kbps speed, dual-redundancy, and LAS function.
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Product Attributes:
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Product Overview
The Yokogawa ALF111-S50 is a FOUNDATION Fieldbus communication module for industrial networks. This module provides 4 ports for connecting Fieldbus segments. The suffix code -S designates the standard type for general applications. Suffix code 5 confirms no explosion protection on this model. Suffix code 0 represents the basic type configuration. The ALF111-S50 operates in low speed voltage mode at 31.25 kbps. Each port supports one Fieldbus segment with its own set of devices. Withstanding voltage from field to system reaches 1500 V AC per minute. For dual-redundancy, you can set up two ALF111 units in annexed slots within the same node unit.
Technical Specifications
General Specifications
| Parameter | Value |
|---|---|
| Part Number | ALF111-S50 |
| Model | ALF111 - FOUNDATION Fieldbus Communication Module |
| Brand | Yokogawa |
| Suffix Code -S | Standard Type |
| Suffix Code 5 | With no explosion protection |
| Suffix Code 0 | Basic type |
| Weight | Approx. 0.40 kg |
Communication Specifications
| Parameter | Value |
|---|---|
| Interface | Foundation fieldbus (low speed voltage mode) |
| Number of Ports | 4 ports (1 segment per port) |
| Transmission Speed | 31.25 kbps |
| Withstanding Voltage (field to system) | 1500 V AC/minute |
| Bus Connection (external) | Pressure clamp terminals (removable terminal block with built-in terminators that can be switched on/off). Connects with terminal board via a dedicated cable. |
Capacity & Performance Specifications
| Parameter | Value |
|---|---|
| Number of Control I/O Channels | Max. 48 points/segment |
| Number of Fieldbus Devices | Max. 32 units per segment (ALF111 counts as one unit) |
| Communication Functions | LAS function, Clock master function |
| Dual-Redundancy | Enabled to set up two units of ALF111 installed in annexed slots in the same node unit |
| Current Consumption | 0.5 A or less |
| Withstanding Voltage (primary to secondary, channel to channel) | 1500 V AC for 1 minute |
Compatible Installation Bases
| Model |
|---|
| ANB10 |
| ANB11 |
| AFV30 |
| AFV40 |
| A2FV50 |
| A2FV70 |
Four Ports & Four Segments
The ALF111-S50 provides 4 independent ports for Fieldbus connectivity. Each port supports one complete Fieldbus segment. This design allows up to 4 separate networks from a single module. Consequently, you can isolate different process areas or device types on separate segments. For large installations, this multi-port configuration reduces the number of required modules significantly.
Transmission Speed & Bus Connection
Transmission speed operates at 31.25 kbps, the standard rate for H1 Fieldbus. Low speed voltage mode ensures compatibility with all FOUNDATION Fieldbus devices. Bus connection uses pressure clamp terminals on a removable terminal block. Built-in terminators can be switched on or off as needed. Additionally, the ALF111-S50 connects to a terminal board via a dedicated cable. For field wiring flexibility, the removable terminal block simplifies maintenance and replacement.
Device Capacity Per Segment
Each segment supports up to 32 Fieldbus devices maximum. The ALF111-S50 itself counts as one unit toward this limit. Number of control I/O channels reaches up to 48 points per segment. By specifying up to 6 points as high-speed scanning type on the ER bus, you can comply with both high- and medium-speed scanning cycles. For this reason, the module handles mixed I/O requirements effectively.
LAS Function & Clock Master
The Yokogawa ALF111-S50 includes the LAS (Link Active Scheduler) function. LAS controls communication on the Fieldbus segment by managing token passing. The Clock Master function provides time synchronization across the network. These features are essential for FOUNDATION Fieldbus operation. Consequently, the ALF111-S50 acts as a full-function bus master on each segment.
Dual-Redundancy Capability
Dual-redundancy is enabled by setting up two ALF111 units in annexed slots. Both units install within the same node unit for coordinated operation. If the primary module fails, the secondary automatically takes over communication. For critical processes, this redundancy ensures continuous network availability. Therefore, the ALF111-S50 suits high-reliability applications.
Withstanding Voltage & Isolation
Withstanding voltage from field to system reaches 1500 V AC for one minute. Additionally, withstanding voltage between primary and secondary sides also reaches 1500 V AC for one minute. Channel-to-channel isolation provides the same 1500 V AC rating. This high isolation level protects the control system from field-side surges. For industrial environments, the Yokogawa ALF111-S50 ensures safe, reliable operation.
Current Consumption & Power
Current consumption stays at 0.5 A or less for normal operation. Low power draw reduces load on the system power supply. Multiple ALF111-S50 modules can operate from the same power source without overloading. For energy-efficient control cabinets, this low consumption proves beneficial. Always verify total system power when installing multiple Fieldbus modules.
Compatible Installation Bases
The ALF111-S50 mounts on several Yokogawa base models. Compatible bases include ANB10, ANB11, AFV30, and AFV40. Additionally, A2FV50 and A2FV70 bases accept this module. Choose the appropriate base for your specific rack configuration. The Yokogawa ALF111-S50 integrates seamlessly with these compatible bases.
Installation Guidelines
Follow these steps for proper installation of the ALF111-S50.
Power down the control system completely before inserting the module.
Select an appropriate base (ANB10, ANB11, AFV30, AFV40, A2FV50, or A2FV70).
Mount the ALF111-S50 firmly onto the base until fully seated.
Secure the module using the retaining screws at top and bottom.
Connect Fieldbus segments to the pressure clamp terminals on the removable block.
Set terminators on or off as needed for each segment's end.
Connect the dedicated cable to the terminal board for field wiring.
Configure dual-redundancy in software if using two ALF111 units in annexed slots.
Power up the system and verify LAS and Clock Master functions are active.
Note: The ALF111-S50 with suffix code 5 provides no explosion protection. For hazardous areas, select an appropriate explosion-protected model instead. Maximum of 32 devices per segment includes the ALF111 as one unit. Dual-redundancy requires two identical ALF111 modules in annexed slots.
Packaging List
One Yokogawa ALF111-S50 FOUNDATION Fieldbus Communication Module
One removable terminal block with built-in terminators
One product documentation manual
One anti-static protective bag
Common FAQs
1. How many ports does the ALF111-S50 provide?
This module provides 4 independent ports for Fieldbus connectivity. Each port supports one complete Fieldbus segment. This design allows up to 4 separate networks from a single module. For large installations, the Yokogawa ALF111-S50 significantly reduces the number of required communication modules.
2. What is the transmission speed of the ALF111-S50?
Transmission speed operates at 31.25 kbps in low speed voltage mode. This speed is the standard rate for H1 FOUNDATION Fieldbus. All compliant Fieldbus devices communicate at this rate. Therefore, the ALF111-S50 works with any standard FOUNDATION Fieldbus device.
3. How many devices can connect per segment on the ALF111-S50?
Maximum device count reaches 32 units per segment. The ALF111-S50 itself counts as one unit toward this limit. Number of control I/O channels reaches up to 48 points per segment. For mixed I/O requirements, the Yokogawa ALF111-S50 handles up to 6 high-speed scanning points on the ER bus.
4. Does the ALF111-S50 support dual-redundancy?
Yes, dual-redundancy is fully enabled for this module. Set up two ALF111 units in annexed slots within the same node unit. If the primary module fails, the secondary automatically takes over communication. For critical processes, the ALF111-S50 with dual-redundancy ensures continuous network availability.
5. What is the withstanding voltage rating of the ALF111-S50?
Withstanding voltage from field to system reaches 1500 V AC for one minute. Between primary and secondary sides, the rating is also 1500 V AC for one minute. Channel-to-channel isolation provides the same 1500 V AC rating. For industrial environments, the Yokogawa ALF111-S50 ensures safe operation with high isolation protection.
Why Choose This Fieldbus Module?
The Yokogawa ALF111-S50 delivers reliable FOUNDATION Fieldbus communication for Yokogawa control systems. Four independent ports provide segment isolation and reduce module count. LAS and Clock Master functions enable full bus master capability on each segment. Dual-redundancy configuration ensures continuous operation for critical processes. Withstanding voltage of 1500 V AC protects the system from field-side surges. For FOUNDATION Fieldbus integration with Yokogawa systems, choose the ALF111-S50.