MITSUBISHI PLC Programmable Logic Controller FX3U-2HC FX3U2HC

Mitsubishi FX3U-2HC High-Speed Counter Module

Overview

The FX3U-2HC is a 2-channel high-speed counter module for the MELSEC-F FX3U platform, designed for fast counting and encoder-related signal processing in compact PLC systems.

Mitsubishi’s official specification page describes it as a module with 2 input channels, support for open collector and differential line driver input formats, selectable 5 VDC, 12 VDC, or 24 VDC input voltage, and 200 kHz or less maximum response frequency in several counting modes.

The hardware manual also identifies it as a special function block and notes that it includes two outputs per channel for comparison-based output actions.

Technical Data

Application Value

The FX3U-2HC fits well in encoder-based counting systems, cut-to-length equipment, winding and feed applications, speed monitoring tasks, and compact positioning-related machinery where a PLC must process fast pulse signals directly.

Because it supports both open collector and differential line driver inputs, it is especially practical in machines that use industrial encoders and require counting reliability across different signal standards.

The module’s comparison outputs also make it useful for simple threshold or position-related control actions without adding extra hardware.

This is an engineering inference based on the module’s published input modes, counting speed, and comparison output capability.

Replacement and Selection Perspective

For replacement work, this module should be matched by channel count, counting frequency, encoder input type, and FX3U compatibility, not only by module width.

In practical systems, the important details are whether the installed machine uses 2 channels, whether the encoder is open collector or differential line driver, and whether the counting mode requires the published high-frequency response.

Matching the same model is usually the safest way to preserve signal handling and machine timing.

FAQ

Q1: What kind of module is FX3U-2HC?
It is a 2-channel high-speed counter module for the Mitsubishi FX3U platform, intended for fast pulse counting and encoder signal processing.

Q2: What applications fit it best?
It fits high-speed counting and encoder applications such as feed control, measuring systems, speed detection, and compact motion-related machinery.

This is an engineering inference based on the module’s published high-speed counting role and encoder-compatible input types.

Q3: Why is the 200 kHz response important?
Because counting frequency determines how fast the PLC can process incoming pulse signals without losing accuracy.

In real applications, higher response capability makes the module more suitable for fast-moving mechanisms and higher-resolution encoders.

Q4: Why do input types matter on this module?
Because the connected encoder or sensor may use either open collector or differential line driver signals.

Matching the correct input type is essential for reliable counting and stable signal interpretation.

Q5: What should be checked before ordering?
Check the installed part number, confirm the required 2-channel structure, verify the encoder signal type, and make sure the machine needs the published high-speed counting performance and FX3U-compatible installation.