MITSUBISHI PLC Programmable Logic Controller Transistor Output FX2N-64MT-001 FX2N64MT001 FX2N-64MT-OO1

Mitsubishi FX2N-64MT-001 | MELSEC-F FX2N Series Main Unit — 64 I/O (32 In / 32 Transistor Out), Expandable to 256 Points, Built-in RS-422, 24VDC

Overview

The Mitsubishi FX2N-64MT-001 is the 64-point transistor output main unit in the FX2N series — Mitsubishi's second-generation compact PLC that was the workhorse of Asian and global small-to-medium machine automation from the mid-1990s through the 2000s and remains widely deployed on installed production equipment today.

As the MPU (Main Processing Unit), the FX2N-64MT-001 is a complete PLC in itself: 

CPU, memory, power supply, I/O, and communication port all in one module, ready to run a program. Nothing additional is required to put it into production use beyond a programming cable, GX Developer or GX Works2 software, and a 24V DC supply.

The -64MT designation within the FX2N family identifies this as the 64-point transistor output variant — the configuration that provides the highest base I/O count in a single FX2N unit while retaining transistor (solid-state) output capability.

The choice between transistor and relay output variants reflects a fundamental application engineering decision: relay outputs (FX2N-64MR) can switch higher inductive loads and AC circuits but are slower and wear out over their rated contact life.

Transistor outputs switch in microseconds, have essentially unlimited switching life, and can generate high-frequency pulse trains — critical for positioning applications using the built-in Y0 and Y1 pulse outputs.

For machines that need both high-speed pulse control of servo or stepper axes and a large I/O base count, the FX2N-64MT-001 is the natural starting point.

The -001 suffix identifies the specific hardware variant and production specification within the FX2N-64MT family.

This unit ships with a weight of approximately 2 kg, reflecting the combined weight of the 64-point I/O terminal board, the CPU module, and the built-in 24V DC power conditioning circuitry.

Key Specifications

I/O Architecture — Inputs, Transistor Outputs, and Expansion

The 32 digital inputs (X0–X37 in FX2N octal notation) accept 24V DC signals from sensors, switches, and pushbuttons.

Inputs X0 through X5 double as high-speed counter inputs, capable of handling pulse trains up to 60 kHz from encoders, proximity sensors in high-speed counting applications, and stepper motor position feedback.

The 32 transistor outputs (Y0–Y37) are solid-state switches — each output connects an internal +24V supply to the output terminal when active, making them source (PNP) type outputs.

Outputs Y0 and Y1 are the pulse output channels: in combination with the built-in pulse output function (accessible via PLSY, PLSR, and DRVA/DRVI motion instructions), these two outputs can generate pulse trains at up to 100 kHz for stepper motor or servo amplifier positioning — without requiring any additional pulse generator modules. 

For machines needing only one or two axes of positioning alongside the base I/O, the built-in pulse outputs eliminate the FX2N-1PG-E cost entirely.

Extension I/O modules attach to the right side of the base unit, each providing additional digital or analog I/O points. The FX2N extension bus supports up to 256 total I/O points, accommodating a mixture of digital input modules (FX2N-16EX, FX2N-32EX), digital output modules (FX2N-16EY, FX2N-32EY), and analog modules (FX2N-2AD, FX2N-4AD, FX2N-2DA, FX2N-4DA).

Special function modules — including the FX2N-1PG-E positioning units, high-speed counter modules, and communication modules — also attach in the extension chain and consume I/O points from the 256-point total.

Processing Power and Instruction Set

The FX2N's processing speed of 0.08 microseconds per basic instruction places it substantially faster than the original FX and FX2C series, and the instruction set expanded significantly over the FX/FX2 predecessors.

The FX2N's 200+ instructions include the full range of IEC 61131-3 equivalent functions needed for machine automation: bit logic, timer/counter operations, data comparison and arithmetic, structured data manipulation, floating-point math, string handling, and the FX-series-specific motion, communication, and positioning instructions.

The 8000-step program memory accommodates machine programs of meaningful complexity — a typical single-axis packaging machine program with position control, sequence logic, HMI communication, and fault handling typically fits in 2000–5000 steps.

For larger programs, a memory cassette (FX2N-ROM-8L for 8k, FX2N-EEPROM-8L for 8k with EEPROM backup) expands capacity and provides non-volatile program storage without battery dependency.

The FX2N supports both regular (1ms to 3276.7s) and high-speed (0.1ms to 327.67ms) timers, 200 general counters (up to 32,767 counts) and 32-bit high-speed hardware counters for encoder feedback and pulse counting.

Data registers provide 7000 D registers for variable storage, with the first 500 (D0–D499) designated retentive (battery-backed).

Communication and Networking

The built-in RS-422 port (with 9-pin D-Sub connector on the base unit) provides the primary programming and monitoring interface. GX Developer (legacy) and GX Works2 software connect to this port via a programming cable (SC-09 or USB-SC09-FX) for program upload/download, online monitoring, and diagnostic access. The same RS-422 port also handles:

N:N Link networking: Up to 8 FX2N PLCs can form a peer-to-peer network sharing data registers and bit devices without programming additional communication instructions — the link data exchange is handled automatically by the PLC's OS.

Computer link (RS422): The FX2N can communicate with SCADA software, HMI panels, and supervisory computers using Mitsubishi's computer link protocol over the RS-422 port.

Optional extension communications: RS-232C, RS-485, CC-Link, PROFIBUS, Ethernet, and other network interfaces are available as optional communication modules that attach to the FX2N's left-side special module connector.

FAQ

Q1: The FX2N-64MT-001 has 32 transistor outputs. What is the maximum output current per channel and in total?

Each transistor output channel is rated for 0.5A at 5–30V DC. However, the total load current across all simultaneously active outputs is limited by the unit's internal power supply capacity — typically around 8A for the entire output group on the FX2N-64MT.

For applications where all 32 outputs might be simultaneously active at their individual ratings (32 × 0.5A = 16A), the total load must be managed to stay within the internal power budget.

In practice, most applications do not have all outputs simultaneously at full load, but this sum must be evaluated during system design.

Q2: The built-in pulse outputs (Y0, Y1) are listed at 100 kHz. Is this the same 100 kHz as the FX2N-1PG-E module?

Yes, both the built-in Y0/Y1 pulse outputs on the FX2N-64MT and the FX2N-1PG-E module's pulse output generate pulse trains at up to 100 kHz.

The difference is how they are controlled: the built-in outputs use PLSY, PLSR, DRVA, and DRVI instructions executed in the PLC's ladder program — fast and adequate for most positioning tasks. 

The FX2N-1PG-E provides a dedicated BFM-based positioning processor with 7 operation modes (including homing, two-speed, interrupt-type positioning) that the built-in pulse output instructions do not replicate directly.

For simple point-to-point positioning with the built-in outputs, the -1PG-E module is unnecessary.

For complex positioning sequences requiring homing, two-speed approach, or interrupt-triggered stopping, the -1PG-E adds capability beyond the built-in output's instruction set.

Q3: Is the FX2N-64MT-001 still supported by Mitsubishi for replacement parts and software?

The FX2N series has been discontinued by Mitsubishi Electric. Mitsubishi's current recommendation for new machine designs is the FX5U (MELSEC iQ-F series), which provides significantly higher performance, built-in Ethernet and PROFINET, and expanded motion control capability.

For maintenance of existing FX2N-based machines, GX Works2 software continues to support FX2N programming and monitoring.

The FX2N-64MT-001 is available through the industrial electronics surplus market. 

Mitsubishi also continues to offer repair services and some spare parts for the FX2N through their service network for a defined support period post-discontinuation.

Q4: What is the maximum program size and can it be expanded beyond the built-in 8000 steps?

The built-in RAM holds 8000 program steps.

A memory cassette installed in the cassette socket on the base unit's front panel can expand this to 16,000 steps (FX2N-ROM-16L or FX2N-EEPROM-16L).

The memory cassette also provides non-volatile program storage — EEPROM-type cassettes retain the program without battery backup, while the base unit's built-in RAM requires the lithium backup battery (typically 3–5 year life) to retain the program during power loss. 

For long-running installations where battery maintenance access is difficult, using an EEPROM cassette eliminates the battery-dependent program retention concern.

Q5: Can the FX2N-64MT-001 communicate directly with Mitsubishi servo amplifiers (MR-J, MR-JE series) for position control?

The FX2N-64MT-001 can control MR-J and MR-JE series servo amplifiers through two methods.

First, the built-in Y0 and Y1 transistor pulse outputs connect to the servo amplifier's pulse input terminals for position control at up to 100 kHz. 

Second, for enhanced control with more sophisticated positioning features, one or more FX2N-1PG-E modules provide dedicated positioning processing. For full servo loop closure with electronic gear ratio, cam profile, and synchronisation, the FX2N-series approach via pulse output is adequate for most single and dual-axis applications but does not match the capability of a dedicated motion controller like MELSERVO or SIMOTION.

Mitsubishi's application notes provide wiring examples for connecting FX2N PLCs to MR-J2(S), MR-J3, MR-JN, and MR-JE amplifiers.