Mitsubishi FX3UC-32MT-LT PLC Controller

The Mitsubishi FX3UC-32MT-LT is a compact programmable logic controller from the FX3U series, featuring 16 digital inputs and 16 transistor outputs (32 I/O total). It is designed for high-speed applications including positioning, motion control, and Ethernet-based networking. The “-LT” suffix indicates a built-in Ethernet port and a real-time clock (RTC). The unit operates on 24V DC and supports expansion up to 384 I/O points using FX2N and FX3U extension modules.

Input/Output Specifications

Inputs (16 points): 24V DC sink/source (type: Sink/source selectable per common). Input voltage range: 20.4–28.8V. Input current: 7 mA typical. Response time: adjustable from 0.2 ms to 70 ms. Eight inputs can be used as high-speed counters (up to 100 kHz, 2-phase). Outputs (16 points): Transistor (NPN sink) rated at 0.5A per point (resistive), 24V DC. Two outputs are high-speed pulse trains (100 kHz) for servo/stepper positioning. Short-circuit protection (current limit) is built-in.

CPU Performance

The FX3UC-32MT-LT uses a 32-bit RISC processor with a basic instruction execution time of 0.21 µs (LD instruction). Program memory: 64K steps (flash memory, no battery needed). Data registers (D): 8000 words (retainable 2000 words via battery backup optional). Real-time clock (RTC) with year/month/day/hour/minute/second, backed by a lithium battery (CR2032, life 5 years). The unit includes 3 high-speed interrupts (1–10 ms intervals).

Built-in Communication

• Ethernet port (RJ45): 10/100Base-T, supports MC protocol (socket communication), Modbus TCP, and SLMP (Seamless Message Protocol).

• USB programming port (mini-B): for connection to GX Works2 or GX Developer (transfer speed 12 Mbps).

• RS-422 programming port (8-pin mini DIN): for legacy programming console.

• RS-485 port (terminal block): for N:N network, Modbus RTU, or parallel link (up to 38.4 kbps).

Positioning and Motion Control

The built-in positioning functions support up to 2 axes of independent or interpolated motion using the high-speed pulse outputs. Positioning instructions include PLSY (pulse Y), PLSR (ramp), and DRVI/DRVA (relative/absolute). The controller also supports two 100 kHz high-speed counters for encoder feedback, enabling closed-loop stepper control.

Expansion Capabilities

Up to 8 extension modules (FX2N, FX3U series) can be connected, including digital, analog, and temperature input/output modules. The maximum total I/O is 384 points. Additionally, the FX3UC can control up to 16 remote I/O stations via the CC-Link network (using an FX3U-16CCL-M module).

Power Supply

Supply voltage: 24V DC (20.4–28.8V). Power consumption: 35 W typical (including internal 5V for expansion). The unit has a built-in 24V DC sensor supply (400 mA) for powering inputs and external sensors. Reverse polarity protection and surge suppression are provided. The power supply includes a 2A slow-blow fuse (replaceable).

Environmental Ratings

Dimensions (W x H x D): 90 mm x 86 mm x 75 mm. Weight: 0.5 kg. Operating temperature: 0 to 55°C; storage: -25 to 75°C. Humidity: 10% to 90% non-condensing. Vibration: 2 g (10–55 Hz). Protection class: IP20. The unit is UL 508 and CE certified, RoHS compliant.

Programming Software

GX Works2 (version 1.62 or higher) or GX Developer (version 8.50 or higher) supports the FX3UC series. Programming languages: ladder diagram, SFC, and structured text (ST). Online editing allows changes while the PLC is in RUN mode. Built-in memory can store up to 4,000 comments and 500 recipes.

Typical Applications

Ideal for high-speed packaging machines, small assembly robots, labelers, and cut-to-length systems. The built-in Ethernet enables connection to SCADA systems or data logging to a SQL database.

Ordering and Documentation

Order number: FX3UC-32MT-LT. Includes terminal blocks and a programming cable (USB). Manual: FX3U Series User's Manual (Hardware) JY997D16501.