MITSUBISHI ELECTRIC MELSERVO MR-J2S- A - Manual (Page 20)

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1. FUNCTIONS AND CONFIGURATION
1. FUNCTIONS AND CONFIGURATION
1.1 Introduction
The Mitsubishi MELSERVO-J2-Super series general-purpose AC servo is based on the MELSERVO-J2
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 RS-232C or RS-422 serial communication function, a MR Configurator (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-J2-Super series servo motor is equipped with an absolute position encoder which has
the resolution of 131072 pulses/rev to ensure more accurate control as compared to the MELSERVO-J2
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 500kpps high-speed pulse train is used to control the speed and direction of a motor and
execute precision positioning of 131072 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.