ALF111-S50/F9S00

The Yokogawa ALF111-S50/F9S00 is a Foundation Fieldbus communication module designed for Yokogawa N-IO/FIO systems. It provides four low-speed voltage-mode Foundation Fieldbus ports, each supporting one fieldbus segment at a transmission rate of 31.25 kbps. The module supports LAS and clock master functions, dual-redundant configuration, and communication with up to 32 fieldbus devices per segment.

Foundation Fieldbus Communication

The ALF111 provides four independent fieldbus ports for connecting field devices to the control system. Each port corresponds to one Foundation Fieldbus segment and uses low-speed voltage-mode communication.

Key communication characteristics include:

• Number of ports: 4
• Segments: 1 segment per port
• Transmission speed: 31.25 kbps
• Maximum fieldbus devices: 32 units per segment, including the ALF111 module
• Communication functions: Link Active Scheduler (LAS) and Clock Master

The module supports up to 48 control I/O points per segment. High- and medium-speed scanning cycle requirements can be accommodated by specifying up to 6 I/O points as high-speed scanning types on the ER bus.

Redundancy and System Configuration

The ALF111 supports dual-redundant configuration. Two ALF111 modules can be installed in the designated adjacent slots within the same node unit to establish a redundant arrangement.

For system planning, the maximum of 32 fieldbus devices applies to each segment, with the ALF111 itself counted as one device. This limit should be considered when calculating the available device capacity for each connected segment.

Fieldbus Connection and Installation

The ALF111-S50/F9S00 uses a pressure clamp terminal block for external fieldbus connections. Its specified option code /F9S00 identifies the Fieldbus pressure clamp terminal block, model ATF9S-00.

The removable terminal block incorporates built-in terminators that can be switched on or off. The module can also connect to a terminal board through a dedicated cable.

Supported installation platforms include:

• ANB10 series
• ANB11 series
• AFV30 series
• AFV40 series
• A2FV50 series
• A2FV70 series

Electrical Characteristics

The module has a maximum current consumption of 0.5 A. Its specified withstand voltage is 1500 V AC for one minute, covering field-to-system isolation and isolation between the primary and secondary sides and between channels.

These isolation ratings are relevant when checking electrical separation requirements between field wiring and system-side circuits.

Technical Specifications

Parameter	Specification
Model	ALF111-S50/F9S00
Brand	Yokogawa
Product Type	Foundation Fieldbus Communication Module
Application	N-IO/FIO
Communication Interface	Foundation Fieldbus, low-speed voltage mode
Number of Ports	4
Segments per Port	1
Transmission Speed	31.25 kbps
Maximum Control I/O Points	48 points per segment
High-Speed Scanning	Up to 6 I/O points specified as high-speed scanning types on the ER bus
Maximum Fieldbus Devices	32 units per segment, including ALF111
Communication Functions	LAS function, Clock Master function
Redundancy	Dual-redundant configuration
External Connection	Pressure clamp terminal block
Terminal Block Model	ATF9S-00
Terminator	Built-in, switchable on/off
Terminal Board Connection	Dedicated cable
Installation Platforms	ANB10, ANB11, AFV30, AFV40, A2FV50, A2FV70
Current Consumption	0.5 A or less
Withstand Voltage	1500 V AC for 1 minute
Isolation	Field-to-system; primary-to-secondary; channel-to-channel
Weight	0.40 kg

Model and Suffix Identification

The complete ordering number identifies the standard module configuration and its fieldbus terminal block option.

Code	Specification
ALF111	Foundation Fieldbus Communication Module for N-IO/FIO
-S	Standard type
5	Without explosion protection
0	Basic type
/F9S00	Fieldbus pressure clamp terminal block option
ATF9S-00	Associated pressure clamp terminal block model

The /F9S00 option is particularly relevant when checking replacement configurations because it specifies the terminal block arrangement supplied with the module.

Frequently Asked Questions

Q: How many Foundation Fieldbus segments can the ALF111-S50/F9S00 support?

A: The module provides four ports, with one Foundation Fieldbus segment per port. Therefore, one module supports four fieldbus segments.

Q: What is the maximum number of fieldbus devices supported per segment?

A: Each segment supports a maximum of 32 fieldbus devices. The ALF111 module itself counts as one unit toward this limit.

Q: Can two ALF111 modules operate in a redundant configuration?

A: Yes. The ALF111 supports dual redundancy using two modules installed in the designated adjacent slots within the same node unit. The system configuration must accommodate the specified installation arrangement.

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