Mitsubishi MELSEC Q Q25UDEHCPU PLC

The Mitsubishi MELSEC Q Q25UDEHCPU is the flagship Universal model CPU from the MELSEC Q series — Mitsubishi's established mid-to-large PLC platform that combines process control, motion control, and safety functions in one modular backplane system. The Q25UDEHCPU supports 260,000 steps of program memory, 28.8 kB standard RAM, and 640k I/O points, with an instruction execution speed of 9.5 ns for basic instructions. Its built-in Ethernet port (100 Mbps) supports EtherNet/IP Class 1 and 3 connections, Modbus TCP, and Mitsubishi's MC protocol — providing out-of-the-box integration with third-party systems, SCADA platforms, and OPC DA/UA servers without communication option boards. The QUDEH suffix denotes built-in Ethernet and high-speed Universal CPU with the enhanced instruction set required for complex numerical and process control programs.

The Q series system architecture supports hot-swap of all I/O and communication modules — a critical feature for Saudi 24/7 process plants where module replacement during system operation eliminates costly production shutdowns. Redundancy is achieved with a dual-CPU configuration (Q25UDEHCPU + Q25UDEHCPU in tracking cable configuration), providing automatic CPU switchover in under 20 ms on CPU failure or communication error — meeting the hot-standby requirement of Saudi Aramco and SABIC process automation standards. The system also supports power supply redundancy (dual QPS power supplies on the same base unit) and I/O module redundancy through CC-Link IE Field Network remote station duplication.

The MELSEC Q platform has the longest continuous deployment record of any Mitsubishi PLC in Saudi Arabia, with thousands of Q-series systems operating in Aramco GOSPs, SABIC polymer plants, SWCC desalination trains, and SEC substation automation applications across the Kingdom. The Q25UDEHCPU is the standard CPU specification for process upgrade projects where existing MELSEC Q infrastructure is being expanded, and for new projects where the larger scale or existing engineering team familiarity with the Q platform justifies its selection over the newer iQ-R. It is also the standard for safety system integration projects where the MELSEC QS (safety) CPU operates alongside the Q25UDEHCPU on the same multi-slot backplane.

Razz Middle East holds Q25UDEHCPU units, Q-series power supplies, I/O cards, and communication modules in local Riyadh stock. Our MELSEC-certified engineers provide migration studies for customers transitioning from older Q-series CPU models (Q06UDEH, Q13UDEH) to Q25UDEHCPU, and prepare project documentation to Saudi Aramco and SABIC automation engineering standards. SAR project pricing with commissioning support is available within 4 hours of RFQ.