Mitsubishi FX2N Series Modules: FX2N-128MR-ES/UL

Technical Dossier

Product Details And Specifications

Mitsubishi Electric FX2N Series: Comprehensive Module Range and Technical Overview

The Mitsubishi Electric MELSEC FX2N series represents one of the most widely deployed compact PLC platforms in global heavy industry. Installed across petrochemical complexes, nuclear auxiliary systems, refinery process lines, and continuous manufacturing facilities, the FX2N platform established a benchmark for high-density I/O integration within a compact DIN-rail footprint. Its 16-bit CPU architecture, high-speed pulse output capability (up to 100 kHz), and broad expansion module ecosystem made it the preferred controller for machine OEMs and system integrators throughout the 1990s and 2000s. Installed base estimates place FX2N units in active service across Asia-Pacific, Europe, and the Americas, with a significant proportion operating in legacy environments where replacement with newer platforms is constrained by engineering cost or process continuity requirements.

The Evolution of FX2N Architecture

The FX2N series succeeded the FX2 and FX0N platforms, introducing an expanded instruction set (over 200 basic and applied instructions), a faster scan cycle, and support for up to 256 I/O points on the base unit with expansion to 512 points via extension modules. The internal bus architecture uses a proprietary Mitsubishi backplane protocol incompatible with the later FX3U and FX5U generations, which is a critical consideration for maintenance engineers planning partial upgrades. FX2N units communicate via RS-422 (programming port) and support optional RS-232C and RS-485 adapters. The series entered end-of-life status in the mid-2010s, with Mitsubishi Electric formally recommending migration to the FX5U platform. However, the installed base remains substantial, and long-term spare parts support is a documented operational requirement for facilities with 10–20 year maintenance cycles.

FX2N Full Catalog & Functionalities (SKU List)

Main CPU / Base Units

• FX2N-16MR-ES/UL: 8 DC input / 8 relay output base unit, 16 I/O points total.
• FX2N-32MR-ES/UL: 16 DC input / 16 relay output base unit, 32 I/O points total.
• FX2N-48MR-ES/UL: 24 DC input / 24 relay output base unit, 48 I/O points total.
• FX2N-64MR-ES/UL: 32 DC input / 32 relay output base unit, 64 I/O points total.
• FX2N-80MR-ES/UL: 40 DC input / 40 relay output base unit, 80 I/O points total.
• FX2N-128MR-ES/UL: 64 DC input / 64 relay output base unit, 128 I/O points total — mixed/combined digital I/O unit.
• FX2N-32MT-ESS/UL: 16 DC input / 16 transistor (sink) output, high-speed pulse output to 100 kHz.
• FX2N-64MT-ESS/UL: 32 DC input / 32 transistor (sink) output base unit.

Digital Input (DI) Expansion Modules

• FX2N-16EX: 16-point DC 24V digital input expansion module.
• FX2N-32EX: 32-point DC 24V digital input expansion module.

Digital Output (DO) Expansion Modules

• FX2N-16EYR: 16-point relay output expansion module, 2A per point.
• FX2N-16EYT: 16-point transistor (source) output expansion module.
• FX2N-32EYR: 32-point relay output expansion module.

Analog I/O Modules (AI/AO)

• FX2N-4AD: 4-channel analog input module, 12-bit resolution, ±10V / 4–20mA selectable.
• FX2N-4DA: 4-channel analog output module, 12-bit resolution, ±10V / 4–20mA selectable.
• FX2N-8AD: 8-channel analog input module, 12-bit resolution.
• FX2N-2AD: 2-channel analog input, compact form factor for space-constrained panels.
• FX2N-2DA: 2-channel analog output module.

Communication & Network Adapters

• FX2N-232-BD: RS-232C communication board, mounts directly to CPU unit.
• FX2N-485-BD: RS-485 communication board for multi-drop network configurations.
• FX2N-CNV-BD: Conversion board for connecting FX0N/FX2 expansion modules to FX2N base units.
• FX2N-16CCL-M: CC-Link master module, supports up to 64 remote I/O stations.

Special Function Modules

• FX2N-1PG: Single-axis pulse generator module for open-loop positioning control.
• FX2N-10PG: High-speed single-axis positioning module, 1 MHz pulse output.
• FX2N-1RM-SET: Remote maintenance module for dial-up modem communication.

Sourcing Hard-to-Find & Obsolete FX2N Parts

The FX2N series reached official end-of-production status, and new stock from authorized distribution channels is no longer available for the majority of base unit models. DriveKNMS maintains a dedicated inventory of tested surplus and refurbished FX2N modules sourced from decommissioned plant equipment, OEM overstock, and controlled liquidation channels. For facilities operating FX2N-based control systems under long-term maintenance agreements — particularly in chemical processing, water treatment, and discrete manufacturing — DriveKNMS provides lifecycle extension support including: verified replacement units for obsolete base CPUs, matched expansion modules for existing I/O configurations, and cross-reference assistance for identifying compatible FX3U or FX5U migration paths where full replacement is required. All units are individually tested prior to dispatch. Requests for specific model numbers, firmware versions, or quantity requirements should be submitted directly to the procurement team.

Quality Control for the FX2N Range

FX2N modules present specific test challenges due to their integrated backplane bus architecture and the age-related degradation patterns common in units removed from long-running installations. DriveKNMS applies a structured test protocol to all FX2N inventory: each CPU base unit undergoes power-on verification, scan cycle timing measurement, I/O point-by-point functional test (both input polling and output switching), and RS-422 programming port communication verification using GX Developer or GX Works2. Analog modules (FX2N-4AD, FX2N-4DA, FX2N-8AD) are tested for channel-to-channel isolation, zero/span calibration accuracy, and linearity across the full input/output range. Communication boards (FX2N-232-BD, FX2N-485-BD) are verified for signal integrity and baud rate stability. Units that fail any test parameter are quarantined and not offered for sale. Test records are available upon request for critical applications.