• ● Executes positioning control with the motion profile table and advanced synchronous control with parameter settings.
• ● Connects remote devices via CC-Link IE TSN. The PLC CPU reads/writes the data of the remote devices.
• ● Supports the digital oscilloscope that collects data synchronized with the motion operation cycle and displays the waveforms data,
     helping users check the operations.
• ● Reusing the existing projects helps reduce the program development time.

[An example of programming in Simple Motion mode]

Utilization of Existing Programs

The existing MELSEC iQ-R/MELSEC-Q series devices and programs are reusable in a new system of RD78G Motion module that supports the Simple Motion mode.

Lineup

Improved Performance

Reuse of Existing Projects

The existing projects of a Simple Motion module can be reused. This enables reduction in program development time.

RD77MS→RD78G

Select [Change Module] in the navigation menu of GX Works3 to convert the Simple Motion module project to a Motion module project.
After the conversion, set the network parameters, servo amplifier parameters, and other parameters.

QD77MS→RD78G

Select [Import Simple Motion Module Data] in the navigation menu of GX Works3 to import the parameters of QD77MS.
After the import, set the network parameters, servo amplifier parameters, and other parameters.

Firmware of RD78G Motion Module

The Simple Motion mode is supported by RD78G with firmware version 16 or later.
To obtain the firmware update files, contact your local sales office.

Positioning Control

Positioning control is easily executed using a motion profile table.

Programming

The Motion module easily executes positioning operation with the instruction in a sequence program that starts a positioning data of the motion profile table. To meet various application needs, the Motion module offers various types of control, such as linear interpolation, two-axis circular interpolation, fixed-pitch feed, and continuous path control.

Advanced Synchronous Control

Synchronous control can be achieved using software instead of controlling mechanically with gear, shaft, clutch, speed change gear or cam, etc.

• Synchronous control can be flexibly started/ended for each axis, enabling the synchronous control axis and positioning control axis to be used within the same program.
• Command generation axis, servo input axis, or synchronous encoder axis ^*1 can be set as the input axis.
• The output axis is operated with a cam. The following three operations can be performed with the cam functions: linear operation, two-way operation, and feed operation.
• An incremental synchronous encoder ^*2 can be connected via MR-J5-G(-RJ)/MR-J5W2-G servo amplifier.

*1. Supported by MELSERVO-J5 series.
*2. When configuring an absolute position system, use an encoder of HK series servo motors.

[Command generation axis]
Command generation axis is the axis that performs only the command generation.
It is controlled independently of other axes connected to servo amplifiers. (not counted as a control axis)

Parameter Settings

Continuous Operation to Torque Control

When using this control, you can switch from position control to torque control continuously without stopping the servo motor.

• The current positions are always tracked even in torque control, and therefore positioning is executed smoothly in position control after switched from the torque control.
• Position control is smoothly switched to torque control without stopping the servo motor.

Auxiliary Functions

Inter-Module Synchronization

The inter-module synchronization function can synchronize the control timings among multiple Motion modules on the same base unit.
A CPU and each I/O module are synchronized, and thus the I/O signals from different machines can be synchronized.

Virtual Servo Amplifier

The virtual servo amplifier function enables operations of a virtual servo amplifier as if an actual unit is connected. When the virtual servo amplifier is set as a servo input axis of synchronous control, the Motion module executes synchronous control with virtually generated input commands. In addition, this function is used to simulate an axis without an actual connection.

Automatic Return

When remote stations are back to normal status after disconnected due to a data link error, this function automatically returns the disconnected stations to the network and restarts data link.
When defective components need to be replaced in one of the machines in a production line or one of the units in a machine, only the machine or the unit can be partly turned off without powering off the whole system.

Read/Write Operation of Standard Stations

• The PLC CPU sends/receives link devices to/from standard stations (remote stations other than the motion control stations) through a Motion module.
• One-to-one communication is possible between the master and remote stations.
• The PLC CPU can be programmed using the signals of the remote stations.

Mark Detection

This function latches data responding to a trigger signal input to a servo amplifier.
The compensation amount is calculated based on the latched data, and the error is compensated using a compensation axis.
A high-accuracy mark detection at 1 μs is available.

CC-Link IE TSN Safety Communication Function ^*1

CC-Link IE TSN enables control of safety and non-safety communications realizing a flexible system whereby safety communications can be easily incorporated into the main control network.
In the following system which integrates safety and non-safety communications, the safety CPU checks the safety signals received via the safety remote I/O module and outputs the safety signals (STO, etc.) to the servo amplifiers. Outputting safety signals via the network eliminates the need for wiring of safety signals to a safety controller and a servo amplifier.

*1.Supported by MELSERVO-J5 series.

Optional Data Monitor

Servo operation is monitored with extensive servo data acquired via CC-Link IE TSN. The acquired data can be transferred to IT system or transferred and displayed on any user-created GOT screen in the network. The target data for monitoring can be flexibly changed during operation.

Driver Communication ^*1

The driver communication function of the servo amplifiers enables the master axis to transmit its torque data to the following axes, and the servo motors of the following axes are driven on the basis of the transmitted torque data.

*1.Supported by MELSERVO-J5 series.

Engineering Environment

MELSOFT GX Works3

MELSOFT GX Works3 has a variety of features which help users create projects and conduct maintenance more flexibly and easily.
Our variety of engineering software (GX Works3, drive system sizing software, and FA Integrated Selection Tool, etc.) fully covers all stages of development processes from parameter settings to maintenance of Motion module, servo amplifier, and servo motors.

System Design

Programming (Positioning)

Programming (Advanced Synchronous Control)

Debug/Maintenance

Functions List

	Motion Module
	RD78G16	RD78G8	RD78G4
Maximum number of control axes	16	8	4
Minimum operation cycle [μs] *1	250
Servo amplifier connection method	CC-Link IE TSN (Communications speed: 1 Gbps/100 Mbps)
Connectable servo amplifier	MR-J5-G, MR-J5W-G, MR-J5D-G4     More details MR-JET-G     More details
Maximum distance between stations [m(ft.)]	100 (328.08)
Control modes	Position control, Speed control, Torque control, Synchronous control, Cam control
Positioning control	Position control, Linear interpolation (Up to 4 axes), Circular interpolation (2 axes), Helical interpolation
Acceleration/deceleration process	Trapezoidal acceleration/deceleration, S-curve acceleration/deceleration
Positioning control method	Motion profile table
Home position return	Driver home position return*2
Manual control	JOG operation, Manual pulse generator operation, Inching operation
Auxiliary functions	Forced stop, Hardware stroke limit, Software stroke limit, Absolute position system, Digital oscilloscope function, Acceleration/deceleration time change, Inter-Module Synchronization , Target position change, Torque limit value change, Speed change, Override, CC-Link IE TSN safety communication function*3
Common functions	Driver Communication , Mark detection, Virtual servo amplifier, Event history, Optional data monitor
Engineering environment	MELSOFT GX Works3
Number of I/O occupying points	32
5VDC internal current consumption [A]	1.93
Mass [kg]	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.
• *3. Supported by MELSERVO-J5 series.