Mitsubishi Q50UDEHCPU MELSEC-Q Universal CPU, 500k Steps

Q50UDEHCPU Universal model Q-series CPU, decoded

The Mitsubishi Q50UDEHCPU is a MELSEC-Q Universal model sequence CPU module with 500k steps of program capacity, a built-in Ethernet port, a USB port and an LD instruction time of 9.5 ns. The name reads as follows: Q is the MELSEC-Q platform, 50 is the program size class (500k steps), UD marks the Universal model, E means built-in Ethernet and H the high-performance type, and CPU is the module type. One of the two largest UDEH processors, with 500k steps of program capacity and a 2000 kB program memory. It is found in large water, power and processing plants where a single controller carries thousands of devices and extensive structured code.

Seven Star LLC supplies the Q50UDEHCPU in Oman and the GCC as an independent supplier in Muscat, not affiliated with the manufacturer. The figures on this page come from the manufacturer’s product data and selection guide.

Q50UDEHCPU technical specifications

Memory sizes follow the manufacturer’s selection guide: the Q50UDEHCPU has 2000 kB of program memory for 500k steps. Communications supported by the built-in port include program upload and download, remote monitoring and maintenance, HMI connection, an FTP server and SNTP time synchronization.

How the Q50UDEHCPU executes and communicates

The CPU runs a stored-program cyclic scan: inputs are refreshed, the sequence program is executed, and outputs are refreshed, with direct access available where a faster response is required. Backed-up device memory and the clock are held by the battery, so the battery must be checked as part of routine maintenance.

The built-in Ethernet port provides 16 connections shared between MELSOFT engineering access and MC protocol, plus one FTP connection. This lets a SCADA, HMI or historian read device data without an extra network module, while engineering software connects over the same port or over USB.

Where the Q50UDEHCPU fits in a MELSEC-Q system

The CPU sits in the CPU slot of a Q main base and works with the Q-series power supplies, digital and analog I/O, positioning, counter and network modules. In multi-CPU configurations on the high-speed base units (Q35DB, Q38DB, Q312DB) a Universal CPU can be the first CPU alongside motion, robot, CNC or C-language CPUs. Sibling processors in the same family include the Q03UDVCPU, Q04UDVCPU, Q06UDVCPU, Q13UDVCPU and Q26UDVCPU (UDV type) and the Q04UDEHCPU, Q13UDEHCPU and Q50UDEHCPU (UDEH type).

Choose it for systems already built around a Q50UDEH or when a Q26UDEH or smaller CPU has run out of program memory. Note that its depth (115 mm) and current draw (0.5 A) differ from the smaller UDEH models, which matters when checking base and power supply loading.

Lifecycle and availability

The manufacturer lifecycle listing for Q50UDEHCPU shows end-of-life on 02.10.2026, last time buy on 30.08.2029 and end of support on 31.12.2036. That means new stock is limited and surplus or remaining inventory is the realistic source, so confirm availability early and plan a migration path to the iQ-R series for long-lived plants.

Selection and ordering checklist for the Q50UDEHCPU

• Confirm the exact model and suffix on the nameplate: Q50UDEHCPU is not interchangeable with other sizes without a program size check.
• Compare program size: 500k steps here, against the project size shown in the engineering software.
• Check the 5 VDC load of the whole base against the power supply rating; this CPU draws 0.5 A.
• Decide whether a memory card is needed for logging, parameters or program storage.
• Confirm firmware and serial number prefix when the CPU is a spare for a validated installation.
• Request the battery type and replacement interval that your maintenance plan expects.

Installation, commissioning and maintenance

Mount the Q50UDEHCPU in the CPU slot of the main base with the power off, fit the backup battery supplied or specified for the system, and connect engineering software over USB or Ethernet. After downloading the project, set the clock, verify the parameters for I/O assignment and check the error history for any latched alarms.

For service, keep a documented project backup, a spare battery and, where downtime is costly, a spare CPU of the same model. Replace the battery on a fixed schedule, because data held in battery-backed memory can be lost if the battery runs flat while the system is powered down.

Typical applications in Oman and the GCC

Q-series CPUs of this class are installed in water treatment and desalination plants, power and utility switchgear, oil and gas auxiliaries, and food and packaging lines across Oman and the GCC. Cabinets in these regions see high ambient temperature, dust and humidity, so the CPU should live in a ventilated, clean cabinet with dust-filtered airflow.

The Q50UDEHCPU is commonly bought as a spare to keep an existing Q-based installation running rather than for new designs, because the Q platform has entered its lifecycle phase-out and the iQ-R series is the manufacturer’s forward path.

Q50UDEHCPU within the Universal model family

Information to send with an RFQ

• Part number Q50UDEHCPU and quantity
• Nameplate photo including serial number and firmware version for spares
• Base unit and power supply model in the existing rack
• Required condition and any traceability or packing requirements
• Delivery location in Oman or the GCC and required lead time

Documents and quotation

A Mitsubishi selection guide covering the Q-series CPU line is attached on this page and lists the memory, speed and communication data used here. For wiring, installation and instruction details, refer to the manufacturer’s manuals for the Universal model QCPU.

Send the Q50UDEHCPU part number, quantity and delivery location and Seven Star LLC will confirm availability and send a quotation.