Mitsubishi Electric MELSERVO-JN Series, Instruction Manual

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1. FUNCTIONS AND CONFIGURATION
1. FUNCTIONS AND CONFIGURATION
1.1 Introduction
The Mitsubishi Electric MELSERVO-JN series general-purpose AC servo is based on the MELSERVO-J3
series, and retains its high performance, with some limitations in functions.
It has position control, internal speed control, internal torque control and positioning modes. Further, it can
perform operation with the control modes changed, e.g. position/internal speed control, internal speed/internal
torque control and internal 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 serial communication function, a MR Configurator installed personal computer
or the like can be used to perform parameter setting, test operation, status display monitoring, gain adjustment,
etc.
With one-touch tuning and real-time auto tuning, you can easily and automatically adjust the servo gains
according to the machine.
The servo amplifier has the tough drive function that continues the operation not to stop a machine in such
situation when normally an alarm is activated.
The MELSERVO-JN series servo motor is equipped with an incremental encoder which has the resolution of
131072 pulses/rev to ensure the positioning with a high accuracy.
(1) Position control mode
Up to 1Mpps high-speed pulse train is used to control the speed and the direction of a servo 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 the parameter.
(2) Internal speed control mode
A parameter-driven internal speed command (max. 8 speeds) is used to control the speed and the direction
of a servo motor precisely and smoothly.
There are also the acceleration/deceleration time constant setting in response to the speed command and
the servo lock function at a stop time.
(3) Internal torque control mode
An internal torque command (0.0% to 100.0%) is used to control the torque output by the servo motor. To
prevent unexpected operation under no load, the speed limit function (internal setting) is also available for
application to tension control, etc.