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MELSEC iQ-R Series


CC-Link IE TSN Motion module RD78G


Create new value with MELSERVO-J5 Unlock performance with a total drive solution.

Maximize system performance


For evolution of machines

  • Performance improvement
  • Program standardization

For flexible system

  • Integration with connectible devices


For quick operation start

  • Tool enhancement
  • Improved drive system usability


For prompt detection and
diagnosis of failures

  • Predictive/preventative maintenance
  • Corrective maintenance

For utilization of existing

  • Interchangeability with previous
    generation models


These Motion modules with multiple-core processors enable to configure a high-speed, large system by supporting the CC-Link IE TSN real-time open network.

  • Performs positioning control such as linear interpolation using function blocks. The programming is easy: users just need to set positioning data to the function blocks.
  • Connects to various modules such as servo amplifiers and I/O modules via CC-Link IE TSN. This connectivity allows you to configure a servo system more flexibly.
  • Supports a consistent engineering environment that is capable of handling tasks ranging from system design to debugging and maintenance.
  • The Motion modules can be directly programmed to distribute load control with PLC CPUs. This ensures that performance will not be degraded even when the number of axes is increased.


MELSEC iQ-R series

  • Maximum number of control axes:
    128 axes/module (RD78GHV)
    256 axes/module (RD78GHW)
  • Minimum operation cycle *1:31.25 [μs]
  • ST language program capacity:
    Built-in ROM max. 16 MB + SD memory card

*1. The operation cycle varies by the number of
control axes and the models.

RD78G4/ RD78G8 RD78G16/ RD78G32 RD78G64

MELSEC iQ-R series

  • Maximum number of control axes:
    64 axes/module (RD78G64)
  • Minimum operation cycle *1:
    62.5 [μs] Enhanced functions
  • ST language program capacity:
    Built-in ROM max. 16 MB
    + SD memory card

*1. The operation cycle varies by the number of
control axes and the models.

Minimum operation cycle:31.25μs Max number of control axes:256軸Industry leading level

*1. The values are applicable when RD78GH is used.


Open integrated networking across the manufacturing enterprise

CC-Link IE TSN supports TCP/IP communications and applies it to industrial architectures through its support of TSN enabling real-time communications.
With its flexible system architecture and extensive setup and troubleshooting features make CC-Link IE TSN ideal for building an IIoT infrastructure across the manufacturing enterprise.

* TSN: Time Sensitive Networking

* IIoT: Industrial Internet of Things

Open integrated networking across the manufacturing enterprise

More details

Servo Amplifier MR-J5(W)-G

Servo Amplifier MR-J5 series

speed frequency response:31.25μsCommand communication cycle 31.25µsIndustry-leading level

The MELSERVO-J5 series high-performance, industryleading servo amplifiers feature a unique control engine that is more powerful than ever before.
These servo amplifiers can connect to CC-Link IE TSN to perform high-speed, high-precision control.
Each multi-axis servo amplifier drives a maximum of either two or three servo motors (depending on the model of servo amplifier chosen), simplifying wiring and enabling a compact machine at a lower cost.

More details


Programming using the internationally standardized PLCopen® Motion Control FBs is possible.
Selectable programming languages vary depending on the controllers:

  • Motion module: structured text language (ST)
  • PLC CPU: ladder diagram (Ladder), function block diagram/ladder diagram (FBD/LD), and structured text language (ST).

Select the controller and programming language according to the necessity of high-speed operation and the complexity of the operation.

programming by PLC CPU and Motion module
  • Reduced programming burden

This programming method is perfect for users who prefer to use only PLC CPU programs.

A PLC CPU program starts operation of the Motion module, eliminating the need for users to create another program for the Motion module, reducing programming burden.
The PLC CPU program supports the internationally standardized PLCopen® Motion Control Function Blocks, and therefore people other than the program designer can understand the programming, leading to reduced design and maintenance time.

programming by PLC CPU only
  • Control load distribution
  • Reduced cycle time

This programming method is perfect for demanding applications which require high-speed, complicated motion operation.

[Processing details]

  • The PLC CPU starts Motion module programs.
  • The Motion module performs operation of double precision floating-point numbers and polynomials.
  • The Motion module performs motion control.

Motion modules can execute complex operations in place of the PLC CPUs. This reduces the operation burden on PLC CPUs and results in a shorter cycle time.

Acceleration/Deceleration Methods

Three types of acceleration/deceleration methods are available: trapezoidal acceleration/deceleration, jerk acceleration/deceleration, and acceleration/deceleration time fixed.

Acceleration/Deceleration Methods

*1 Input acceleration.

Jerk acceleration/deceleration

The acceleration changes gradually. For example, when a vehicle loaded with a workpiece accelerates gradually, the load will not swing back and forth after acceleration. The jerk is maintained during acceleration. When the vehicle has almost reached the target speed, the jerk is decelerated. Adjusting jerk in this way achieves smooth acceleration/deceleration while also shortening the time it takes to reach the target speed. The speed creates a S-curve shape.

Synchronous Control

Synchronous control is performed using function blocks that operate as software-based mechanical modules such as gear, shaft, clutch, speed change gear, and cam.

  • The number and the combination of the synchronous modules are flexibly selected, achieving optimized operation.
  • The following two types of cam data are available: cam data and cam data for a rotary knife
  • Complex cam control is possible by flexibly switching cams.
  • Positioning and synchronous control can be performed together in the same program.
  • Cam for a rotary knife can be easily created in MELSOFT GX Works3 or by using function blocks.
  • Synchronous control using a synchronous encoder is possible. Enhanced functions

[An example of packing machine program (FBD)]

An example of packing machine program (FBD)

Synchronous EncoderEnhanced functions

The Motion module easily performs synchronous control by setting a synchronous encoder to "Real encoder axis" and creating a program with function blocks.
The number of command pulses can be adjusted using the function block (MC_Gearin) or a parameter.

Synchronous Encoder

*1. The system shows an example using an incremental synchronous encoder.
      When configuring an absolute position system, use an encoder of HK series servo motors.

Cam control

Create operation profile data *1 (cam data) according to your application. The created cam data is used to control output axis.
The following three cam operations are available: linear operation, two-way operation, and feed operation. Choose one according to your application.

*1. "Operation profile data" is a general name for waveform data, which is used for various applications.

Two-way operation

The beginning and the end of the cam pattern are the same.
Mechanical cams fall into this category.

Two-way operation

Touch Probe Function Enhanced functions

This function latches data responding to a trigger signal input.
The trigger signal can be inputted to the controller using a remote I/O.

Touch Probe Function

GX Logviewer

The graph data of both PLC CPU modules and Motion modules can be viewed on a single tool, GX LogViewer. This tool helps you efficiently analyze data from two different modules. The following two functions are provided for logging: data logging function (offline) and real-time monitor.

GX Logviewer

Data Logging Function

The function performs data logging by a specified time interval based on the logging setting (trigger condition, data collection) written to the motion system from the engineering tool. The results are saved as a data logging file.
Up to 10 data settings can be simultaneously logged for the Motion system.

Real-time monitor Future support planned

Up tp 32 collected motion system data can be displayed in real time.

GX Logviewer

Engineering Environment


MELSOFT GX Works3 has a variety of features which help users create programs and conduct maintenance more flexibly and easily.
This software includes motion control setting to support all Motion module development stages - from setting parameters to programming, debugging, and maintenance.


Network Configuration Settings

[Network configuration settings]

  • Intuitive network settings with drag-and-drop operations and a graphical screen view

[Automatic detection]

  • By clicking the [Connected/Disconnected Module Detection] button, the connection status of slave devices is automatically detected and the CC-Link IE TSN configuration screen is generated.

Automatic detection

Easy Programming Through Structured Text Language
  • Structured text programs are composed of function blocks, increasing program readability.
  • Modularization of the programs increases their reusability.
  • The consistent, common operability on a single engineering tool improves usability further.
  • A wide selection of programming elements in the MELSOFT Library contributes to reducing programming time.
  • The program is created by dragging & dropping programming elements, which simplifies the programming process.
  • A startup time is reduced using the simulator of MELSOFT GX Works3 that can debug a program without an actual machine. *1

Easy Programming Through Structured Text Language

*1. This function will be supported by the Motion module in the future.

Programming Using Labels
  • The control axes of the Motion modules and I/O signals are defined as label variables, which enables easy reuse of programs and helps to improve programming efficiency.
  • The global labels created in the Motion module project can be used in PLC CPUs. Enhanced functions

Programming Using Labels

Functions List

  Motion Module
RD78GHW RD78GHV RD78G64 RD78G32 RD78G16 RD78G8 RD78G4
Maximum number of control axes 256 128 64 32 16 8 4
Minimum operation cycle [μs] *1 31.25 62.5 Enhanced functions
Servo amplifier connection method CC-Link IE TSN (1 Gbps)
Maximum distance between stations [m(ft.)] 100(328.08)
Connectable servo amplifier MR-J5-G, MR-J5W-G     More details
Control modes Position control, Speed control, Torque control, Synchronous control
Positioning control Position control, Linear interpolation (Up to 4 axes), Circular interpolation (2 axes)
Acceleration/deceleration process Trapezoidal acceleration/deceleration, Jerk acceleration/deceleration,
Acceleration/deceleration time fixed method
Programming language PLC CPU: Sequence program, FBD/LD, ST
Motion module: ST
Homing functions Data set method, Driver homing method *2
Manual control JOG operation
Auxiliary functions Forced stop, Hardware stroke limit, Software stroke limit, Absolute position system,
Data logging, Acceleration/deceleration time change,
Target position change, Torque limit value change, Speed change, Override
Common functions Touch probe, Slave emulate, Event history, Monitoring of servo data Enhanced functions
Engineering environment MELSOFT GX Works3
Number of I/O occupying points 32 points + 16 points (empty slot) 32
5VDC internal current consumption [A] 2.33
Mass [kg] 0.44 0.26
  • *1.The minimum operation cycle varies depending on the number of control axes and the model.
  • *2.The home position return method set in a driver (a servo amplifier) is used.