Mitsubishi PLC CPU Units R08CPU

Mitsubishi Electric’s MELSEC series PLC CPU units are the core of the control system. According to application scale and functional requirements, they are mainly divided into several major product lines: iQ-R, iQ-F, L series, and Q series.

I. MELSEC iQ-R Series

The iQ-R series is Mitsubishi Electric’s current mainstream modular PLC platform. Its CPU unit types are the most extensive, covering all requirements from entry-level to large-scale systems.

1. Programmable Controller CPU (Standard Type)

Program capacity ranges from 10K steps to 1200K steps, allowing flexible selection according to system scale. The basic operation processing speed (LD instruction) of standard CPUs can reach 0.98 ns.

Entry-level CPU units (R00/R01/R02) have built-in non-volatile memory, requiring no backup battery and reducing maintenance costs such as battery replacement. They also integrate an Ethernet communication port and an SD memory card slot, and support data logging. Functions that required multiple units in the Q series can now be implemented by a single CPU unit.

2. CC-Link IE Built-in CPU (EN Type)

Models include R04ENCPU, R08ENCPU, R16ENCPU, R32ENCPU, R120ENCPU, etc. Based on the standard CPU, they have built-in CC-Link IE network functionality, enabling high-speed network communication without installing an additional network unit.

3. Safety CPU

Models such as R08SFCPU-SET, R16SFCPU-SET, R32SFCPU-SET, R120SFCPU-SET are provided, with program capacities from 80K steps to 1200K steps. The dedicated capacity for safety control programs is 40K steps. These models are provided as sets with a safety function module (R6SFM), making them suitable for safety control scenarios requiring human-machine collaboration.

4. Process CPU

These include R08PCPU, R16PCPU, R32PCPU, R120PCPU, etc., with program capacities covering 80K to 1200K steps. They can simultaneously execute advanced PID control and high-speed sequential control, making them suitable for PLC replacement scenarios in DCS systems. SIL2 process CPUs (R□□PSFCPU-SET) and duplex systems supporting redundancy are also available.

5. Other Dedicated CPUs

• Motion CPU: R16MTCPU, R32MTCPU, R64MTCPU, supporting up to 16–64 axes.

• C Language Controller: R12CCPU-V, supporting real-time execution of C language programs on the PLC.

• WinCPU: R102WCPU-W, equipped with Windows 10, integrating control and information processing on the base unit.

Core Technical Advantages

The MELSEC iQ-R series supports the IEC 61131-3 standard programming languages, including ladder diagram, ST, SFC, FBD, etc. The programming environment is MELSOFT GX Works3. CPU units feature advanced functions such as a Web server function, database function, security function, and inter-module synchronization.

Taking R08CPU as an example, its specific specifications include: program capacity 80K steps/320 KB, device/label memory 1188 KB, data memory 5 MB, maximum I/O points 4096, equipped with USB 2.0 and Ethernet (RJ45) interfaces, power supply voltage DC 5 V (provided by a dedicated power supply unit), and PC MIX value up to 419 instructions/μs.

II. MELSEC iQ-F Series

The iQ-F series is a compact all-in-one PLC. The CPU unit integrates the power supply, CPU, and I/O, making it suitable for small-to-medium-scale control.

FX5U series is the main product, with key features including:

• Control scale: 32 to 384 points (CPU module itself 32/64/80 points)

• Built-in analog function: 2-channel 12-bit analog voltage input + 1-channel analog voltage output

• Built-in high-speed counter: maximum 8 channels, 200 kHz pulse input

• Built-in positioning function: maximum 200 kpps, 4-axis pulse output (transistor output type)

• Built-in Ethernet port and RS-485 port

• Program capacity: 64K steps

FX5S and FX5UJ are more simplified models. FX5S is positioned as entry-level, while FX5UJ is equipped with a USB connector and IoT functions. The programming software for the iQ-F series is also GX Works3.

III. MELSEC-L Series

The L series uses a base-less structure, saving control panel space, and is suitable for applications with installation space requirements. CPU units come standard with 24-point built-in I/O and are standard-equipped with various functions such as counters, positioning, and CC-Link.

Main models include:

• L02SCPU/L02CPU: program capacity 20K steps, basic operation speed 40–60 ns, I/O points 1024

• L06CPU: program capacity 60K steps, basic operation speed 9.5 ns, I/O points 4096

• L26CPU: program capacity 260K steps (the largest in the series), suitable for larger-scale control

The L series is also equipped with a display unit (L6DSPU), making it easy to check system status and modify settings.

IV. MELSEC-Q Series

The Q series was the main modular PLC platform before the introduction of the iQ-R series. Some models are still available, but they are gradually being replaced by the iQ-R series.

Q series CPU units cover program capacities from 14K steps to 252K steps. They are equipped with USB and RS-232 interfaces, and the power supply voltage is DC 5 V (provided by a dedicated Q series power supply unit). A typical model such as Q03UDVCPU has 4096 I/O points, 30K steps program capacity, 1.9 ns basic operation speed, and supports SD cards and extended SRAM cards.

V. Selection Points Summary