OMRON R88D-H310G SmartStep 2 Servo Drive: Compact AC Servo Amplifier for 1kW Motors

The OMRON R88D-H310G is a single-phase 200-240V AC servo drive from the SmartStep 2 series, designed to drive OMRON R88M series servo motors up to 1kW. This advanced servo amplifier supports position, speed, and torque control modes, making it suitable for a wide range of motion control applications. With built-in positioning functions (internal memory for up to 64 points) and Modbus RTU communication, the R88D-H310G offers a cost-effective solution for systems requiring precise motion without a dedicated motion controller.

Electrical Specifications and Power Ratings

The R88D-H310G operates on single-phase 200-240V AC (±10%), 50/60Hz, with a rated output current of 6.9A RMS and a maximum peak current of 17.3A. It provides continuous output power of 1kW (max 3kW for short-term overload). The drive uses IGBT technology with PWM sinusoidal control, achieving efficiency above 95%. Built-in regenerative resistor handles deceleration energy, and an external resistor can be added for high-inertia loads. The control circuit requires 24 VDC (optional) for logic retention.

Control Modes and Performance

In position control mode, the R88D-H310G accepts line driver or open-collector pulse trains up to 500 kHz, supporting electronic gear ratios from 1/100 to 100. Speed control mode uses an internal speed reference or external analog voltage (±10V) with a speed range of 1:5000 and speed regulation of ±0.01% (with encoder feedback). Torque control mode offers linear torque output with 1% ripple. The internal positioning mode (point table) stores up to 64 positions, accelerations, decelerations, and dwell times, which can be selected via digital inputs, reducing PLC overhead.

Feedback and Auto-Tuning Features

The drive supports incremental encoder (20-bit resolution, 1,048,576 pulses/rev) or absolute encoder (17-bit or 20-bit) feedback from R88M motors. It features an advanced auto-tuning algorithm that automatically measures motor inertia and sets optimal gain parameters (position, speed, and torque loop) in under 1 second. The adaptive filter suppresses mechanical resonance up to 200 Hz. A built-in oscilloscope function allows monitoring of command and feedback waveforms via the PC software (CX-Drive).

Protection and Safety Functions

The R88D-H310G includes comprehensive protection: overcurrent, overvoltage, undervoltage, overload (electronic thermal), regenerative error, encoder error, overspeed, and position deviation overflow. It meets safety standards with STO (Safe Torque Off) as a built-in function (IEC 61800-5-2, SIL2). The drive also features dynamic braking (by external resistor) and a built-in cooling fan with speed monitoring. The control PCB is coated for moisture and dust resistance (class 3C2).

Typical Applications and Integration

Typical applications include pick-and-place machines, small conveyor drives, indexing tables, packaging machinery, and laboratory automation. The R88D-H310G can be controlled by any PLC or motion controller via pulse train (CW/CCW, sign + pulse, or quadrature) or Modbus RTU commands. Using OMRON’s CP1H or CJ2 PLC, users can achieve coordinated multi-axis control via the Modbus network without dedicated positioning modules. The drive is also compatible with the OMRON SmartStep configuration software for monitoring and parameter backup.

Physical Installation and Environmental Ratings

The drive measures 180mm (H) x 80mm (W) x 155mm (D) and weighs 1.4 kg. Mounting is via DIN rail (vertical orientation) or screw panel. Ambient operating temperature is 0°C to 55°C (derating above 45°C), humidity 20% to 90% non-condensing. Storage temperature -20°C to 65°C. The unit is rated IP20 for protection against solid foreign objects. Wiring uses spring-clamp or screw terminals for main power and control signals. The R88D-H310G complies with CE, UL, and RoHS directives.