Mitsubishi MELSEC FX1S Series Modules: FX1S-30MT-001

Technical Dossier

Product Details And Specifications

Mitsubishi MELSEC FX1S Series: Comprehensive Module Range and Technical Overview

The Mitsubishi MELSEC FX1S series is a compact, fixed I/O programmable logic controller platform developed by Mitsubishi Electric for light-to-medium industrial automation applications. Deployed across chemical processing plants, water treatment facilities, packaging lines, textile machinery, and building automation systems globally, the FX1S occupies the entry-level tier of the MELSEC FX family. Its all-in-one architecture integrates CPU, power supply, and I/O into a single housing, making it a standard specification in installations where panel space and budget are constrained. Despite its compact form factor, the FX1S supports high-speed pulse output (up to 100 kHz), interrupt inputs, and serial communication via optional adapters, giving it a functional footprint that exceeds its physical size. Installed base across Asia-Pacific, Europe, and the Americas remains substantial, and demand for spare units and replacement modules continues from facilities operating legacy lines with no near-term migration plan.

The Evolution of FX1S Architecture

The MELSEC FX1S was introduced as a successor to the FX0S and FX0N compact PLC lines, inheriting the ladder logic programming model and GX Developer / GX Works2 software compatibility that defined the FX generation. Early FX1S units shipped with transistor (sink/source) and relay output variants, covering 10-, 14-, 20-, and 30-point I/O configurations. The internal CPU executes basic instructions at 0.55–0.7 µs per step, with program memory of 2,000 steps — sufficient for the majority of machine-level sequencing tasks it was designed to handle.

As the FX family matured, Mitsubishi introduced the FX1N, FX2N, FX3S, and FX5U lines with expanded memory, analog I/O support, Ethernet connectivity, and higher-speed processing. The FX1S was not updated to match these capabilities; instead, it was positioned as a fixed, cost-optimized platform. By the mid-2010s, Mitsubishi Electric formally transitioned new design recommendations toward the FX3S and FX5U. The FX1S entered end-of-life status for new production, though Mitsubishi continued to supply spare units through authorized channels for an extended period. As of 2026, the FX1S is classified as a mature/legacy product. Facilities running FX1S-based systems face compatibility constraints when sourcing replacements: the FX1S does not accept FX3 or FX5 expansion modules, and its communication protocol stack (RS-422 via FX1S-485-BD or FX1S-232-BD boards) is not directly interchangeable with newer FX5U communication cartridges. Long-term maintenance therefore depends on the availability of genuine used, refurbished, or new-old-stock (NOS) units from specialist distributors.

FX1S Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified production range of the Mitsubishi MELSEC FX1S series. Units are categorized by output type and I/O point count. All models share the same CPU core and program capacity (2,000 steps).

Relay Output Models (R-type):

FX1S-10MR-001: 6 DC inputs / 4 relay outputs, 100–240 VAC power supply, base unit.
FX1S-14MR-001: 8 DC inputs / 6 relay outputs, 100–240 VAC power supply, base unit.
FX1S-20MR-001: 12 DC inputs / 8 relay outputs, 100–240 VAC power supply, base unit.
FX1S-30MR-001: 16 DC inputs / 14 relay outputs, 100–240 VAC power supply, base unit.
FX1S-10MR-DS: 6 DC inputs / 4 relay outputs, 24 VDC power supply variant.
FX1S-14MR-DS: 8 DC inputs / 6 relay outputs, 24 VDC power supply variant.
FX1S-20MR-DS: 12 DC inputs / 8 relay outputs, 24 VDC power supply variant.
FX1S-30MR-DS: 16 DC inputs / 14 relay outputs, 24 VDC power supply variant.

Transistor Sink Output Models (T-type):

FX1S-10MT-001: 6 DC inputs / 4 transistor sink outputs, 100–240 VAC, high-speed pulse capable.
FX1S-14MT-001: 8 DC inputs / 6 transistor sink outputs, 100–240 VAC, supports 2-axis pulse output.
FX1S-20MT-001: 12 DC inputs / 8 transistor sink outputs, 100–240 VAC, supports positioning control.
FX1S-30MT-001: 16 DC inputs / 14 transistor sink outputs, 100–240 VAC, 100 kHz high-speed pulse output, full-featured base unit — the most widely deployed model in the FX1S range.
FX1S-10MT-DS: 6 DC inputs / 4 transistor sink outputs, 24 VDC power supply variant.
FX1S-14MT-DS: 8 DC inputs / 6 transistor sink outputs, 24 VDC power supply variant.
FX1S-20MT-DS: 12 DC inputs / 8 transistor sink outputs, 24 VDC power supply variant.
FX1S-30MT-DS: 16 DC inputs / 14 transistor sink outputs, 24 VDC power supply variant.

Communication & Option Boards (compatible with FX1S base units):

FX1S-232-BD: RS-232C communication board, mounts directly to FX1S base unit expansion slot.
FX1S-485-BD: RS-485 communication board, enables MODBUS RTU and Mitsubishi protocol networking.
FX1S-422-BD: RS-422 communication board for programming port expansion and HMI connection.

Sourcing Hard-to-Find & Obsolete FX1S Parts

DriveKNMS maintains a dedicated inventory program for legacy Mitsubishi MELSEC FX1S units. As the FX1S series has entered end-of-life status with Mitsubishi Electric's standard distribution channels, procurement through conventional authorized distributors is increasingly unreliable for specific models — particularly the DS-suffix (24 VDC) variants and communication option boards.

DriveKNMS sources FX1S units through a verified secondary market network, including decommissioned equipment from plant closures, manufacturer-certified refurbishment programs, and new-old-stock holdings from regional distributors in Japan, Germany, and the United States. Each unit is individually assessed prior to listing. For customers requiring multiple units for a production line or a standing blanket order for ongoing maintenance, DriveKNMS can structure a reserved inventory agreement to guarantee supply continuity over a defined service period. Customers operating FX1S-based systems with no planned migration to FX5U or iQ-F within the next 3–5 years are advised to establish a buffer stock of critical base units and communication boards now, while supply remains accessible.

Quality Control for the FX1S Range

All FX1S units processed by DriveKNMS undergo a structured functional verification protocol before dispatch. The procedure covers: power-on self-test confirmation (RUN/ERROR LED status verification); I/O point-by-point continuity and switching test using a dedicated PLC test rig loaded with a standardized ladder program; high-speed pulse output verification on Y0/Y1 outputs for MT-type units (100 kHz signal integrity check); communication board slot functionality test where applicable; and visual inspection of the backplane connector, terminal block, and housing for mechanical integrity. Units that fail any stage of this protocol are quarantined and not dispatched. Test records are retained per unit serial number and are available to customers on request. Relay output (MR-type) units additionally undergo contact resistance measurement and rated-load switching cycle verification to confirm relay service life margin.