The Q20UDVCPU is Mitsubishi Electric’s 20,000-step Universal V model CPU for the MELSEC-Q series — the highest program capacity available within the V model sub-family — sharing the same 1.0 ns execution speed, built-in Ethernet and USB interfaces, and multi-CPU support as the Q13UDVCPU while providing a 54% increase in program memory for the most demanding standalone machine control applications. The Q20UDVCPU targets complex automation systems where 13,000 steps prove insufficient but the extended memory and redundancy features of the Universal Enhanced High-speed family are not required, offering a cost-effective capacity upgrade within the familiar Universal V model platform. The Q20UDVCPU is available through Atlantech Drives — quote within 24-48 hours, worldwide express shipping, 12-month warranty.
What Is the Q20UDVCPU?
The Q20UDVCPU is the top-capacity member of Mitsubishi Electric’s MELSEC-Q Universal V model CPU range. With 20,000 program steps, it provides capacity equivalent to the Q20UDEHCPU Universal Enhanced High-speed model in terms of base step count, but without the UDEH model’s SRAM memory card expansion capability (which extends UDEH models to 80,000–260,000 steps) or redundant CPU support. For applications where 20,000 steps is sufficient and neither memory expansion nor redundancy is required, the Q20UDVCPU offers the same program capacity as the Q20UDEHCPU at a lower hardware cost. The module is programmed using GX Works2 or GX Works3 and is fully compatible with all MELSEC-Q base units and peripheral modules. Multi-CPU configurations with up to four CPUs per base are supported, enabling combined sequence, motion, and process control architectures.
Key Technical Specifications
- Model: Q20UDVCPU
- Series: MELSEC-Q Universal V model
- Program Memory: 20,000 steps
- Execution Speed: 1.0 ns per LD instruction
- I/O Points: Up to 4,096 (local)
- Built-in Interfaces: Ethernet (100BASE-TX), USB (mini-B)
- Number of Mountable Modules: Up to 64 per base
- Multi-CPU Configuration: Supported (up to 4 CPUs per base)
- Power Supply Voltage: 5 VDC (via base unit)
- Operating Temperature: 0°C to 55°C
- Weight: Approx. 0.17 kg
- Compatible Base Units: Q3B, Q5B, Q6B, Q12B, Q25B, Q32B, Q33B, Q35B, Q38B, Q312B
- Programming Software: GX Works2, GX Works3
Compatibility & System Integration
The Q20UDVCPU integrates fully with the MELSEC-Q module ecosystem. For network communication, it supports QJ71E71-100 (Ethernet), QJ61BT11N (CC-Link Ver.2), QJ71MT91 (MODBUS/TCP), QJ71LP21-25 (MELSECNET/H optical), and QJ71BR11 (MELSECNET/H coaxial) communication modules. For analogue I/O, the Q64AD, Q68ADV, Q62DA, and Q68DAVN modules are fully supported. Positioning and motion is handled via QD75MH (up to 4-axis pulse output) or QD77MS (SSCNET III/H servo network) modules. The built-in Ethernet port supports SLMP protocol for direct integration with Mitsubishi GOT2000 HMIs, third-party SCADA systems using MC protocol, and MES platforms via the iQ Mesenger middleware. In multi-CPU configurations, the Q20UDVCPU can exchange up to 8,192 words of shared memory per scan cycle with co-installed motion or process CPUs, enabling tightly coordinated multi-domain control without external communication overhead.
Replacement & Upgrade Notes
The Q20UDVCPU is the recommended upgrade path from the legacy Q20HCPU and Q20UCPU. When replacing a Q20HCPU, the most significant change is the elimination of the need for a separate QJ71E71-100 Ethernet module — the Q20UDVCPU’s built-in Ethernet port handles all standard MC protocol and SLMP communication natively. The freed module slot can be used for an additional CC-Link master, a second analogue module, or left empty. Program migration from GX Developer (Q20HCPU) to GX Works2 (Q20UDVCPU) is performed using GX Works2’s GX Developer project import function; engineers should verify all SM/SD special relay and register references after import, as several assignments changed between the H and Universal model generations. When upgrading from a Q20UCPU (an older Universal model without built-in Ethernet), the migration is simpler — program structure, device assignments, and base unit compatibility are identical, and only the Ethernet module configuration needs to be updated to use the built-in port.
Frequently Asked Questions
Q: What is the practical difference between the Q20UDVCPU and the Q20UDEHCPU for a new machine design?
A: For a new machine with a fixed program that will not exceed 20,000 steps and does not require hot-standby redundancy, the Q20UDVCPU and Q20UDEHCPU offer identical runtime performance. The Q20UDEHCPU is justified when the program may grow beyond 20,000 steps (expandable to 80,000 via memory card), when redundant CPU operation is required for high-availability applications, or when the system will use multiple extension base units beyond the standard Q model limit. For cost-sensitive OEM machine designs with defined, stable programs, the Q20UDVCPU is the more economical choice.
Q: Can the Q20UDVCPU manage a CC-Link network with 64 remote stations?
A: Yes. With a QJ61BT11N CC-Link Ver.2 master module installed in the base unit, the Q20UDVCPU can manage up to 64 remote I/O and remote device stations per CC-Link network. Multiple QJ61BT11N modules can be installed in the same base to manage additional independent CC-Link networks, subject to the base unit’s total current capacity. CC-Link network parameters are configured in GX Works2’s network parameter editor.
Q: Is online program change (OPC) supported on the Q20UDVCPU?
A: Yes. The Q20UDVCPU supports online program change from GX Works2 and GX Works3, allowing ladder rungs, SFC steps, and FB instances to be modified while the CPU is in RUN mode. Changes are applied at the end of the current scan without halting machine operation. The total program size after any OPC operation must remain within the 20,000-step limit; GX Works2 will reject the change and display an error if the new program would exceed capacity.
Do you need more references from this brand? Explore our full catalog of Mitsubishi here: https://atlantechdrives.com/manufacturers/mitsubishi/
