The MR-J2S‑40A is a digital AC servo amplifier in Mitsubishi’s MELSERVO‑J2‑Super family, designed to drive 0.4 kW 200 V‑class servo motors such as the HC‑KFS43, HC‑MFS43 and HC‑UFS43 in CNC, packaging, electronics assembly and general industrial automation equipment. It supports single‑phase 200–230 VAC and three‑phase 200–230 VAC main power and uses a sine‑wave PWM current control system to provide smooth torque, low vibration and high‑response speed control, with a speed frequency response of around 550 Hz or higher for fast, accurate positioning. The standard “A” universal interface accepts high‑speed pulse train commands (up to 500 kpps with differential input, 200 kpps with open‑collector input) and ±10 V analog speed/torque commands, allowing flexible integration with a wide range of motion controllers and PLCs. When used with 17‑bit encoders (131,072 pulses per revolution) on compatible Mitsubishi motors, the drive supports high‑resolution feedback for accurate position control and electronic gearing. Built‑in dynamic braking permits rapid deceleration without an external brake chopper in many cases, and the amplifier supports multiple control modes—position, speed and torque—which can be combined to match application requirements. Comprehensive protection features include overcurrent, regenerative overvoltage, overload (electronic thermal), motor overheat, encoder fault, regenerative fault, undervoltage/sudden power outage, overspeed and excessive error protection, improving system safety and reliability.
Technical Specifications
