MELSEC-F is Mitsubishi Electric's family of compact PLCs. Each main unit combines the CPU, power supply and I/O, and the system expands through expansion boards, special adapters and extension blocks. The most recent MELSEC-F generation is FX3 (FX3S, FX3U and FX3UC), succeeded by MELSEC iQ-F. Most FX3 models are covered by discontinuation notices, and FX3S is the only group without one. TKK supports existing MELSEC-F systems with spares and migration advice toward MELSEC iQ-F.

Lifecycle status by model group

These are the global dates from Mitsubishi Electric's notices. Contact TKK for availability in Thailand.

• FX3S: no discontinuation notice. Still in production.
• FX3U, FX3UC and most extension models (FAM-A-0116-B): make-to-order from 1 Jan 2028, last order date 31 Mar 2028, production ends 30 Sep 2028, and repair runs until 30 Sep 2035.

FX3 main units

• FX3S: 10, 14, 20 or 30 I/O (30 I/O max), 4,000-step program capacity, no battery needed, 0.21 μs per basic instruction, USB and RS-422 ports, and 2-axis positioning on transistor types.
• FX3U: 16, 32, 48, 64, 80 or 128 I/O on the main unit, up to 256 local I/O or 384 with CC-Link/AnyWireASLINK, 64,000 steps, and 0.065 μs per basic instruction. It has 3 built-in positioning axes at 100 kHz, or 4 axes at 200 kHz with two FX3U-2HSY-ADP adapters (the built-in axes are then unavailable).
• FX3UC: 16, 32, 64 or 96 I/O, connector-type (24 V DC), with the same programming specs and speed as FX3U and 3-axis positioning.

Expansion and options

• Expansion boards, such as FX3G-232-BD, FX3G-485-BD and FX3U-USB-BD, for communication, analog and I/O.
• Analog and temperature: FX3U-4AD-ADP, FX3U-4DA-ADP, FX3U-4AD-PT-ADP, FX3U-4AD-TC-ADP, FX3U-4AD, FX3U-4DA and FX3U-4LC.
• High-speed counting and positioning: FX3U-4HSX-ADP, FX3U-2HSY-ADP, FX3U-2HC, FX3U-1PG and FX3U-20SSC-H (SSCNET III).
• Networks: FX3U-16CCL-M, FX3U-64CCL, FX3U-128ASL-M, FX3U-32DP, FX3U-64DP-M, FX3U-CAN and FX3U-J1939.
• Memory and power: FX3U-FLROM cassettes, FX3G-EEPROM-32L, FX3U-CF-ADP, FX3U-1PSU-5V and FX3U-32BL battery.

Programming software

FX3 controllers are programmed with GX Works2, which supports Ladder, SFC, ST and Structured Ladder/FBD. GX Developer Ver.8 also supports FX3U and FX3UC. FX Configurator-FP is used to set up the FX3U-20SSC-H.

Models in the series

Main MELSEC-F FX3 models, with their status from Mitsubishi Electric notices. Many options work only with FX3U or FX3UC main units, so contact TKK to check supply and replacements before you order.

• FX3S main units: FX3S-10M, FX3S-14M, FX3S-20M and FX3S-30M with relay or transistor outputs and AC or DC power, plus FX3S-30M□/ES-2AD with built-in analog input. FX3S is still in production.
• FX3U main units: FX3U-16M, FX3U-32M, FX3U-48M, FX3U-64M, FX3U-80M and FX3U-128M (MR, MT and MS types, with ES, DS and UA1 power). Last order 31 Mar 2028.
• FX3UC main units: FX3UC-16MT, FX3UC-32MT, FX3UC-64MT and FX3UC-96MT (/D and /DSS), FX3UC-16MR/D-T and FX3UC-16MR/DS-T. Last order 31 Mar 2028.
• I/O extensions: FX2N-32E and FX2N-48E units, FX2N-8E and FX2N-16E blocks, and FX2NC-16E, FX2NC-32E and FX2NC-64ET blocks. Last order 31 Mar 2028.
• Analog and temperature: FX3U-4AD, FX3U-4DA, FX3U-4LC and FX3UC-4AD (last order 31 Mar 2028), and the FX3U-4AD-ADP, FX3U-4DA-ADP, FX3U-3A-ADP, FX3U-4AD-PT-ADP and FX3U-4AD-TC-ADP adapters.
• Positioning and counting: FX3U-1PG, FX3U-2HC, FX3U-20SSC-H, FX3U-2HSY-ADP and FX3U-4HSX-ADP. Last order 31 Mar 2028.
• Network modules: FX3U-16CCL-M, FX3U-64CCL, FX3U-128ASL-M, FX3U-32DP, FX3U-64DP-M, FX3U-CAN and FX3U-J1939. Last order 31 Mar 2028.
• Serial adapters: FX3U-232ADP-MB and FX3U-485ADP-MB.
• Expansion boards: FX3G-232-BD, FX3G-485-BD, FX3G-2AD-BD and FX3G-1DA-BD, and FX3U-232-BD, FX3U-422-BD, FX3U-485-BD and FX3U-USB-BD (FX3U boards last order 31 Mar 2028).
• Memory and power: FX3U-FLROM-16, FX3U-FLROM-64, FX3U-FLROM-64L, FX3U-FLROM-1M, FX3U-1PSU-5V and FX3UC-1PS-5V (last order 31 Mar 2028), plus FX3G-EEPROM-32L, FX3U-CF-ADP and FX3U-32BL.

Migrating to MELSEC iQ-F

Mitsubishi Electric's official replacement is MELSEC iQ-F (FX5S, FX5UJ, FX5U and FX5UC). It is not a drop-in swap: programs and wiring may need changing, and connecting existing extension models may require changing the whole system. Check each model's manual before you plan the change.

• FX3U-16M: FX5U-32M or FX5UJ-24M.
• FX3U-32 to 128-point units: FX5U or FX5UJ combinations.
• FX3UC-16, 32, 64 and 96MT: FX5UC-32, 32, 64 and 96MT.
• FX3U special blocks: FX5-4AD, FX5-4DA, FX5-4LC, FX5-40SSC-S, FX5-CCL-MS, FX5-ASL-M and FX5-DP-M. There is no direct iQ-F replacement for FX3U-32DP, FX3U-CAN or FX3U-J1939.

Running MELSEC-F controllers? Contact TKK about spare availability and a migration plan to MELSEC iQ-F.