Mitsubishi MELSEC FX3U Compact PLC

The Mitsubishi MELSEC FX3U Compact PLC is the high-performance legacy compact controller from the FX3 generation — still widely specified in Saudi Arabia for machine and process applications where the extensive global installed base, comprehensive accessory range, and proven 20-year reliability record outweigh the newer iQ-F FX5U's additional features. The FX3U-128MR/ES provides 64 inputs and 64 relay outputs as standard, with program memory of 64,000 steps — vastly exceeding the requirements of most compact machine applications — and instruction execution speed of 65 ns for basic instructions. Its expansion capability reaches 256 I/O points via FX3U expansion modules, and the comprehensive special function module range covers analog I/O, high-speed counter, positioning, CC-Link communication, PROFIBUS-DP, and CANopen without requiring a motion or communication CPU.

The FX3U's three built-in high-speed counter inputs at 100 kHz and two pulse outputs for positioning (up to 100 kHz open-collector) support encoder feedback and stepper/servo pulse-train positioning on up to 3 axes without any expansion module — a feature that continues to make it the default choice for Saudi OEM machine builders of small CNC accessories, pick-and-place units, and label applicators. RS-232 and RS-485 communication as standard supports Modbus RTU and various inverter communication protocols (Mitsubishi FR-E700/E800 via FREQROL), and the wide range of optional communication boards — Ethernet, CC-Link, PROFIBUS, CANopen — ensures the FX3U can be integrated into virtually any Saudi plant network architecture.

In Saudi Arabia, the FX3U remains the predominant compact PLC in the existing installed base across manufacturing facilities, water treatment panels, and building automation systems installed during the major industrial and infrastructure build-out of the 2000s and 2010s. Saudi facilities maintenance teams are thoroughly familiar with FX3U parameters and programming, and Razz Middle East holds comprehensive spare parts stock — main units, expansion modules, and special function modules — for rapid replacement of failed units at minimal downtime cost. The FX3U is also the standard specification for Saudi MODON factory machine upgrades where the project scope is limited and the client wishes to maintain consistency with the existing machine fleet.

Razz Middle East maintains the deepest FX3U spares holding in Saudi Arabia, with main units (16M through 128M), I/O expansion modules, analog modules, and communication boards in Riyadh stock. We provide same-day despatch for emergency replacement orders and 4-hour RFQ turnaround for project pricing in SAR. Our engineers support FX3U to FX5U migration projects for customers wishing to upgrade to the current-generation platform while reusing existing I/O panel wiring.