MIF4*A | Yokogawa FOUNDATION Fieldbus H1 Module

Product Overview

The Yokogawa MIF4*A is a FOUNDATION Fieldbus H1 communication module designed for Yokogawa Field Control Unit (FCU) platforms. It manages 4 H1 fieldbus segments at 31.25 kbps, serving as the Link Active Scheduler (LAS) and system clock master for up to 32 field devices per segment. The module provides deterministic communication between smart transmitters, valve positioners, and the central controller across multiple active fieldbus loops.

Key Specifications

• Product Family: Yokogawa FCU Communication Module
• Protocol: FOUNDATION Fieldbus H1 (low-speed voltage mode)
• Ports: 4 ports (1 segment per port)
• Transmission Speed: 31.25 kbps
• Max Devices per Segment: 32 units (including the MIF4*A)
• Isolation: 1500 V AC (field-to-system, channel-to-channel, 1 min)
• Power Consumption: Max 2.5 W (5 V DC, ≤0.5 A)
• Bus Connection: Removable pressure clamp terminal block
• Internal Terminators: Switchable onboard terminators
• Operating Temperature: 0°C to +60°C
• Weight: 0.40 kg

Features and Benefits

• 4-port design supports up to 4 independent H1 fieldbus segments from one module
• Link Active Scheduler (LAS) role ensures deterministic loop synchronization
• Channel-to-channel isolation rated at 1500 V AC protects against ground loops
• Switchable internal terminators eliminate need for external termination on short runs
• Removable pressure clamp terminal blocks enable fast field wiring maintenance
• Dual-redundant module pairing provides seamless LAS failover without segment disruption

Applications

• FOUNDATION Fieldbus H1 device integration in CENTUM VP/CS3000
• Smart transmitter and valve positioner network management
• Process control loops requiring deterministic fieldbus communication
• Chemical plant distributed I/O via fieldbus
• Oil refinery instrument modernization projects

FAQ

Q: What does the suffix *A indicate on the MIF4 module?
A: The suffix letter denotes the hardware revision level. MIF4*A is Revision A. Verify compatibility with your specific FCU and CENTUM system version before ordering.

Q: How many field devices can each H1 segment support?
A> Each segment supports up to 32 devices including the MIF4*A module itself.

Q: Does the module include internal terminators?
A: Yes. The module features switchable internal terminators. Enable the terminator if the MIF4*A is at the physical end of the H1 trunk line; disable if an external terminator exists.

Q: What happens during a dual-redundant module failure?
A: In a dual-redundant pair, the primary module operates as the active LAS. If the primary fails, the backup module takes over the LAS token seamlessly without disrupting segment traffic.

Installation Guide

1. Slide the module into the designated FCU rack slot along the guide rails
2. Push firmly until the rear pins connect with the system backplane
3. Engage the locking clips to secure against industrial vibration
4. Verify the position of the built-in terminator switch before activating the field loop
5. Enable internal terminator if the module is at the end of the H1 trunk
6. Connect fieldbus cables to the removable pressure clamp terminal blocks
7. Terminate all cable shields at a single point on the instrument ground bar
8. Configure segment parameters in the CENTUM engineering station

Selection Tips

• Select MIF4*A for FOUNDATION Fieldbus H1 communication in Yokogawa FCUs
• Verify your FCU rack has available slots for communication modules
• Plan H1 segment topology to stay within the 32-device limit per port
• For redundant configurations, order two MIF4*A modules
• Ensure fieldbus cables have compatible pressure clamp termination