Functions And Configuration; Introduction - Mitsubishi Electric Melservo MR-J3-A Instruction Manual

1. FUNCTIONS AND CONFIGURATION

1. FUNCTIONS AND CONFIGURATION

1.1 Introduction

The Mitsubishi MELSERVO-J3 series general-purpose AC servo is based on the MELSERVO-J2-Super series
and has further higher performance and higher functions.
It has position control, speed control and torque control modes. Further, it can perform operation with the
control modes changed, e.g. position/speed control, speed/torque control and torque/position control. Hence, it
is applicable to a wide range of fields, not only precision positioning and smooth speed control of machine tools
and general industrial machines but also line control and tension control.
As this new series has the USB or RS-422 serial communication function, a servo configuration software-
installed personal computer or the like can be used to perform parameter setting, test operation, status display
monitoring, gain adjustment, etc.
With real-time auto tuning, you can automatically adjust the servo gains according to the machine.
The MELSERVO-J3 series servo motor is equipped with an absolute position encoder which has the resolution
of 262144 pulses/rev to ensure more accurate control as compared to the MELSERVO-J2-Super series.
Simply adding a battery to the servo amplifier makes up an absolute position detection system. This makes
home position return unnecessary at power-on or alarm occurrence by setting a home position once.
(1) Position control mode
An up to 1Mpps high-speed pulse train is used to control the speed and direction of a motor and execute
precision positioning of 262144 pulses/rev resolution.
The position smoothing function provides a choice of two different modes appropriate for a machine, so a
smoother start/stop can be made in response to a sudden position command.
A torque limit is imposed on the servo amplifier by the clamp circuit to protect the power transistor in the
main circuit from overcurrent due to sudden acceleration/deceleration or overload. This torque limit value
can be changed to any value with an external analog input or the parameter.
(2) Speed control mode
An external analog speed command (0 to 10VDC) or parameter-driven internal speed command (max. 7
speeds) is used to control the speed and direction of a servo motor smoothly.
There are also the acceleration/deceleration time constant setting in response to speed command, the
servo lock function at a stop time, and automatic offset adjustment function in response to external analog
speed command.
(3) Torque control mode
An external analog torque command (0 to 8VDC) or parameter-driven internal torque command is used to
control the torque output by the servo motor.
To protect misoperation under no load, the speed limit function (external or internal setting) is also available
for application to tension control, etc.
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