Mitsubishi Electric FX2N-128MT-ES/UL MELSEC FX2N Series PLC Main Unit

Designed for high-speed machine control and extensive local I/O integration, the Mitsubishi Electric FX2N-128MT-ES/UL serves as a high-density processing core within the MELSEC FX2N Series PLC family. This main unit features a combined total of 128 local I/O points, utilizing transistor source outputs and highly configurable sink/source inputs to manage complex automation sequences in demanding industrial environments.

Key Technical Features

• High-Density I/O Configuration: Equipped with 64 digital inputs and 64 transistor outputs (source format) integrated into a single compact chassis.
• Advanced Processing Speed: Executes basic instructions at 0.08 microseconds per instruction, ensuring rapid response times for critical control loops.
• Flexible Memory Architecture: Features an 8,000-step internal RAM (battery-backed) with expansion capabilities up to 16,000 steps via memory cassettes.
• Integrated High-Speed Counters: Supports up to 6 channels of high-speed inputs with counting frequencies up to 60 kHz for precise positioning and encoder feedback.
• Dual-Axis Positioning: Built-in independent 2-axis pulse output (up to 20 kHz) for direct control of stepper and servo drive systems.

Industrial Applications

• Multi-Axis Packaging Machinery: Controls high-speed wrapping, sealing, and labeling systems requiring synchronized pulse outputs.
• Material Handling & Conveyor Systems: Manages complex sorting, routing, and tracking configurations across extensive conveyor networks.
• Assembly and Pick-and-Place Stations: Interfaces directly with pneumatic actuators, sensors, and variable frequency drives.
• Specialized Machine Tooling: Provides reliable logic control for custom drilling, cutting, and metal-forming machinery.

Technical Specifications

Connections and Interfaces

Empirical Engineering Insights

Alternative Models & Compatibility

The FX2N-128MT-ES/UL is the global standard model featuring transistor source outputs. It directly replaces older Japanese-market sink-only models (such as the FX2N-128MT-D) in systems where field wiring has been updated to source logic. When migrating legacy applications to the modern MELSEC FX3U series (e.g., FX3U-128MT/ESS), program conversion can be executed via GX Works2, though physical depth and terminal block spacing must be cross-referenced to ensure panel layout compatibility.

Application Pitfalls & Engineering Notes

Ensure that the cumulative current drawn from the 24V DC service power terminals does not exceed 460mA. Overloading this internal supply will cause thermal shutdown or erratic CPU behavior. Additionally, because the transistor outputs are rated for a maximum of 0.5A per single point, inductive loads such as heavy solenoids or magnetic contactors must be suppressed using external flyback diodes to prevent premature output degradation.

Commissioning & Wiring Tips

For high-speed counter inputs (X000 to X007), always use shielded twisted-pair cabling. Route these signal lines completely separate from high-voltage AC power lines and VFD motor cables to prevent electromagnetic interference from corrupting pulse counts. If using the built-in pulse output functions (Y000 and Y001) for positioning, verify that the external load impedance is high enough to limit current draw to 0.3A on these specific high-speed channels.

Installation Guidelines