
Product Overview
The Mitsubishi Electric MELSEC-F Series FX3U PLC CPU is a third-generation, high-performance micro-programmable logic controller (PLC) that represents the flagship model of the renowned FX3 series . Designed as a compact, all-in-one CPU unit with built-in I/O, the FX3U delivers exceptional speed, capacity, and functionality for a wide range of industrial automation applications . With basic instruction processing speeds of just 65ns and a generous 64K step program memory, this controller handles complex control tasks with remarkable efficiency . Available in multiple configurations with built-in I/O points ranging from 16 to 128 points and expandable up to 384 total I/O points via remote networks, the FX3U series provides the flexibility and performance required for small to medium-scale automation systems, from standalone machinery to networked production lines .
Technical Specifications
| Parameter | Details |
|---|---|
| Product Series | Mitsubishi Electric MELSEC-F Series |
| Family Name | FX3U Series (Third-Generation Micro PLC) |
| Power Supply Options |
AC Powered: 100-240V AC (50/60Hz) DC Powered: 24V DC |
| Program Memory | 64K steps RAM (program memory) |
| Device Memory | Auxiliary Relays: 7,680 points Timers: 512 points Counters: 235 points Data Registers: 8,000 points Extension Registers: 32,768 points |
| Basic Instruction Speed | 65 ns (LD contact instruction) |
| Application Instruction Speed | 642 ns (MOV instruction) |
| Built-in I/O Points | Available in 16, 32, 48, 64, 80, and 128-point configurations |
| Total I/O Capacity | 256 points (standard) / 384 points (with CC-Link or AnyWireASLINK) |
| Positioning Function | Built-in 3-axis independent, 100kHz max pulse output |
| High-Speed Counters | 1-phase: 100kHz (6 points) 2-phase: 50kHz (2 points) |
| Programming Port | RS-422, up to 115.2kbps communication speed |
| Special Adapter Support | Up to 6 adapters (left side) |
| Programming Languages | Ladder (LD), Structured Ladder/FBD, Structured Text (ST), SFC |
| Operating Temperature | 0°C to +55°C |
| Storage Temperature | -25°C to +75°C |
| Mounting | DIN rail mounting (standard 35mm rail) |
| Dimensions (WxHxD) | 16-point: 130 x 90 x 86 mm 32-point: 150 x 90 x 86 mm 48-point: 182 x 90 x 86 mm 80-point: 285 x 90 x 86 mm |
| Certifications | CE, UL/cUL, KC, ABS, DNV, LR, GL, BV, RINA, NK, KR |
Model Number Selection Guide
The FX3U series uses a systematic model code to identify specific configurations .
| Model Number | Power Supply | Inputs | Input Type | Outputs | Output Type | Output Logic |
|---|---|---|---|---|---|---|
| FX3U-16MR/DS | 24V DC | 8 points | 24V DC Sink/Source | 8 points | Relay | N/A |
| FX3U-16MT/ES-A | 100-240V AC | 8 points | 24V DC Sink/Source | 8 points | Transistor | Sink (NPN) |
| FX3U-32MT/DSS | 24V DC | 16 points | 24V DC Sink/Source | 16 points | Transistor | Source (PNP) |
| FX3U-48MT/ES | 100-240V AC | 24 points | 24V DC Sink/Source | 24 points | Transistor | Sink (NPN) |
| FX3U-80MR/DS | 24V DC | 40 points | 24V DC Sink/Source | 40 points | Relay | N/A |
| FX3U-128MR/ES | 100-240V AC | 64 points | 24V DC Sink/Source | 64 points | Relay | N/A |
Model Code Decoder:
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MR: Relay Output
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MT: Transistor Output (Sink/NPN)
-
MSS: Transistor Output (Source/PNP)
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ES: AC Power Supply (100-240V AC)
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DS: DC Power Supply (24V DC)
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-A: Denotes specific regional variants (e.g., for Asian market)
Expansion Modules & Options
| Module Type | Model Examples | Description |
|---|---|---|
| I/O Expansion (Powered) | FX2N-32ER, FX2N-48ET, FX2N-32ER-ES/UL | Digital input/output expansion units with built-in power supply |
| I/O Expansion (Unpowered) | FX2N-8EX, FX2N-16EYR | Input/output extension blocks (receive power from main unit) |
| Analog Modules | FX3U-4AD, FX3U-4DA | Analog input/output modules for process control |
| Communication Adapters | FX3U-232ADP, FX3U-485ADP, FX3U-USB-BD | Serial communication adapters for RS-232, RS-485, USB |
| Ethernet Adapter | FX3U-ENET-ADP | Ethernet communication adapter for network connectivity |
| High-Speed Positioning | FX3U-2HSY-ADP | High-speed output adapter for expanded positioning (4 axes, 200kHz) |
| Temperature Control | FX2N-4LC | Temperature control modules for PID applications |
| CC-Link Interface | FX2N-32CCL | CC-Link network module for distributed I/O control |
| Function Expansion Boards | FX3G-4EX-BD, FX3G-2EYT-BD | Input/output expansion boards (4 input or 2 output points) |
| Memory Cassette | FX3U-64K EEPROM | Optional Flash memory cassette for program storage |
Typical Applications
The Mitsubishi FX3U series is ideally suited for a wide range of industrial automation applications requiring reliable, high-speed control in a compact form factor :
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Packaging Machinery: Form-fill-seal machines, cartoners, and labeling systems requiring precise positioning and high-speed sequencing
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Material Handling: Small to medium conveyor systems, sortation units, and pick-and-place stations
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Automated Assembly: Component assembly stations, test equipment, and parts feeders in automotive and electronics manufacturing
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Food & Beverage: Mixing equipment, filling lines, and packaging systems with hygienic requirements
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Textile Machinery: Spinning frames, weaving looms, and finishing equipment requiring synchronized speed control
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Machine Tools: Auxiliary equipment control, tool changers, and part loaders for CNC machines
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Process Control: Batch control, temperature monitoring, and chemical dosing for small-scale processes
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Water Treatment: Pump control, filtration systems, and chemical feed applications
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Building Automation: HVAC control, lighting systems, and access control for small facilities
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Specialty Machinery: Woodworking, printing presses, and plastic molding machines
Why Choose the Mitsubishi MELSEC-F Series FX3U?
The Mitsubishi FX3U Series PLC CPU represents the culmination of decades of PLC development, delivering the perfect balance of high-speed performance, extensive functionality, and proven reliability in a compact, cost-effective package . As the flagship model of the FX3 series, it offers significant advancements over previous generations, with processing speeds nearly three times faster than the FX2N series and substantially expanded memory capacity .
The FX3U's built-in 3-axis positioning at 100kHz eliminates the need for separate motion modules in many applications, reducing system cost and panel space . Its ability to connect up to 6 special adapters without consuming I/O points provides exceptional flexibility for communication, analog, and temperature control requirements . With support for up to 384 total I/O points via CC-Link networks, the system scales gracefully from simple standalone machines to more complex distributed applications .
Backed by Mitsubishi Electric's global reputation for quality and reliability, the FX3U carries comprehensive certifications including CE, UL/cUL, KC, and approvals from 8 major marine classification societies, ensuring worldwide acceptance . Its compatibility with the extensive FX2N expansion module library protects prior investments while enabling gradual system enhancements .
Whether you are building a simple packaging machine, a specialized assembly station, or a small-scale process control system, the FX3U delivers the performance, flexibility, and long-term reliability required for success in today's competitive industrial environment. Choose the Mitsubishi MELSEC-F Series FX3U for proven third-generation performance that stands the test of time.
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