MELSEC iQ-R Series

Overview

The Mitsubishi Electric MELSEC iQ-R, launched in 2015, is the successor to the long-running Q series and represents Mitsubishi's most advanced PLC platform. Built around a high-speed backplane bus rated at 150 MB/s, the iQ-R allows up to four CPU modules — standard logic, motion, process control, and safety — to share the same rack and exchange data transparently every scan cycle without additional programming overhead.

A key differentiator is CC-Link IE TSN, Mitsubishi's Time-Sensitive Networking implementation of the open CC-Link IE Field standard. By layering TSN on standard Gigabit Ethernet (IEEE 802.1AS, 802.1Qbv), CC-Link IE TSN achieves deterministic cycle times as short as 31.25 µs — competitive with traditional dedicated motion buses — while using standard Ethernet cabling and switches.

Programming uses GX Works3, which supports IEC 61131-3 Structured Text, Ladder Diagram, Function Block Diagram, and SFC alongside Mitsubishi's proprietary label programming. The iQ Works integration suite connects GX Works3 with GT Works3 (GOT HMI software) and MT Works2 (motion engineering), allowing a single project database to span controller, HMI, and servo configuration.

Key Features

• Multi-CPU system on shared rack

  Up to four CPU modules (programmable CPU, motion CPU, process CPU, safety CPU) share the iQ-R rack and communicate over the 150 MB/s backplane at 0.22 ms synchronisation intervals — eliminating inter-CPU communication latency that external networked CPUs would incur.
• CC-Link IE TSN — 1 Gbps deterministic

  CC-Link IE TSN uses IEEE 802.1 Time-Sensitive Networking standards over standard Gigabit Ethernet, delivering sub-millisecond determinism across mixed standard/TSN network topologies. Compatible with Mitsubishi MR-J5 servo amplifiers for motion control without a separate motion bus.
• SSCNETIII/H for high-speed motion

  The R16MTCPU motion CPU connects to MR-J4/J5 servo amplifiers via SSCNETIII/H fibre-optic bus at 150 Mbit/s with a 0.88 ms control cycle. Up to 96 axes per motion CPU with full PLCopen MC function block support for synchronisation, gearing, and camming.
• Built-in safety CPU (R08SFCPU)

  The dedicated safety CPU executes IEC 61508 SIL 3 / ISO 13849 PLe safety programs alongside standard logic on the same rack. Safety data is exchanged with CC-Link IE Safety remote I/O without additional gateway hardware.
• iQ Works integrated engineering

  GX Works3 (PLC), GT Works3 (GOT HMI), and MT Works2 (servo) share a single project structure, enabling one-click cross-reference between PLC tag names and HMI screen labels — dramatically reducing configuration errors during commissioning.

Technical Specifications

Typical Applications

The iQ-R is dominant in Japanese manufacturing and has strong installed base across Asia in automotive stamping, semiconductor fabrication, and high-speed assembly. Its multi-CPU architecture is particularly valued in applications requiring concurrent motion, process control, and safety without the latency of inter-PLC communication.

• Semiconductor wafer handling: R16MTCPU with SSCNETIII/H for ultra-precise wafer transport
• Automotive press lines: Multi-CPU rack with motion + safety CPUs sharing tonnage data
• Injection moulding: Process CPU for PID temperature + motion CPU for clamp/injection axes
• Textile machinery: High-speed multi-axis synchronisation via SSCNETIII/H fibre bus
• Robot cell integration: CC-Link IE TSN connecting MELFA robot controllers and iQ-R