MICROMASTER 420 Inverter without filter. Digital microprocessor control. Flux current control for improved dynamic response and optimized motor control. Latest IGBT technology. Linear V/F characteristic. Quadratic V/F characteristic. Multipoint characteristic (programmable V/F characteristic). Flying restart. Slip compensation. Automatic restart following mains failure or fault. Internal PI controller for simple process control. Programmable acceleration or deceleration times from 0 to 650 seconds. Ramp smoothing. Fast current limit for trip-free operation. Fast, repeatable digital input response time. Fine adjustment using a high-resolution 10-bit analog input. Compound braking for controlled rapid braking. Four skip frequencies.