LUST LTi Drives SO84.020.0020.0000.2 Servo One 20 A Controller
The LUST LTi Drives SO84.020.0020.0000.2 is a servo controller from the Servo One family, a platform developed by LUST Antriebstechnik and later marketed under the LTi Drives brand. The ordering code identifies a unit rated at 20 A with an output frequency range from 0 to 400 Hz. Additional identification numbers 70535 and 124202444 are associated with the unit and may be used for traceability, production documentation or order reference.
The Servo One platform was designed around a consistent control core that is shared across all power ratings. This means that commissioning procedures, parameter structures and diagnostic concepts remain the same whether a machine uses a small single axis unit or a large multi axis configuration. For machine builders and maintenance teams, this consistency reduces engineering effort, simplifies documentation and shortens the learning curve when additional axes are added to an existing system.
Product Overview
The SO84.020.0020.0000.2 operates as a single axis servo controller. It draws power from a three phase mains supply and produces a controlled output voltage and frequency for the connected motor. The output stage uses pulse width modulation with a high switching frequency, producing smooth current waveforms and low torque ripple. The control core executes current, velocity and position loops in a closed cascade, each with independently adjustable parameters to match the mechanical characteristics of the load.
The 20 A current class supports medium to large servo motors and moderate to high inertia loads. The 0 to 400 Hz output frequency range allows the drive to operate a motor at low speed with high torque, as required for positioning and holding tasks, and also at high speed for spindle or rotary cutting applications. The drive is intended for cabinet mounting and can be installed alongside other units in a multi axis arrangement.
Key Features and Functional Highlights
Feedback support covers resolvers, incremental encoders and absolute encoders, including high resolution serial protocols used with modern servo motors. Automatic commutation detection and motor identification reduce commissioning effort and minimize the risk of incorrect parameter entry. Parameter sets can be stored internally and transferred between units, which simplifies machine replication and spare parts replacement.
Integrated safety technology includes Safe Torque Off, allowing the drive to be placed in a safe state without removing DC link power. Monitoring functions continuously evaluate current, voltage, temperature and following error, and they trigger defined fault responses when limits are exceeded, protecting the motor and the mechanical system.
An internal brake chopper allows braking energy to be dissipated through an external resistor when the DC bus cannot absorb it. This is important for high inertia loads that must be decelerated quickly. Digital and analog inputs and outputs provide fast interfacing with machine signals such as enable, limit switches, reference pulses and brake control.
Technical Specifications
The SO84.020.0020.0000.2 is designed for a three phase mains connection in the 400 V class. Its 20 A rating provides sufficient output current for medium to large servo motors with short term overload capability for acceleration peaks. Output voltage is variable up to the level available from the DC link, and the output frequency extends from 0 to 400 Hz. The DC link is accessible for shared operation, allowing several drives to be connected to a common DC bus.
Communication with the higher level controller is handled through a fieldbus interface. The Servo One family supports EtherCAT, PROFIBUS, PROFINET, CANopen and EtherNet/IP depending on the option fitted. Analog and digital signal interfaces are also available, allowing the drive to be used in centralized and decentralized motion architectures. A dedicated output for a motor holding brake is provided for vertical axes.
Performance and Advantages
Short current loop cycle times produce fast response to torque commands and minimize following error during dynamic moves. This is valuable in applications involving high acceleration, frequent direction changes or tight contouring tolerances. The velocity loop offers adjustable gain, integral time and filter settings, allowing resonance in the mechanical train to be suppressed without sacrificing bandwidth.
Support for both rotary and linear motors reduces the number of different drive types required in a machine. The shared DC bus capability improves energy efficiency in multi axis systems. The consistent parameter structure across the Servo One range means that engineering data, commissioning knowledge and documentation remain valid when drive sizes change, which shortens project lead times and reduces training requirements.
Application Areas
The SO84.020.0020.0000.2 is used in machine tools for feed and spindle axes, in packaging machinery for high torque sealing and cutting stations, in printing and converting equipment for driven rollers and register control, and in handling and robotics systems for large gantry and rotary axes. It also appears in metal forming machinery, plastics processing equipment, textile machinery and test rigs where high current and precise control are required simultaneously.
Installation and Commissioning
Installation requires attention to cabinet ventilation, cable cross sections, cable routing and shielding. The drive should be mounted vertically with sufficient clearance above and below for convection cooling. Motor cables must be shielded, with the shield bonded to ground at both ends over a large contact area. Feedback cables should be routed separately from power cables. DC bus connections between drives must follow the manufacturer instructions regarding fusing, precharging and cable length.
Commissioning begins with entering motor data, either manually or by selecting a stored dataset. The feedback system is checked for correct direction and resolution. The current loop is verified first, followed by tuning of the velocity and position loops. Fieldbus parameters, limit values, safety functions and fault responses are then configured and stored. A test run at reduced speed confirms correct direction, brake timing and limit switch behavior.
Maintenance and Diagnostics
The drive records fault codes and operating data that assist with troubleshooting. Maintenance consists of checking cabinet cooling, verifying terminal tightness, inspecting shield connections and cleaning the heatsink. Fan units should be replaced at the recommended service interval. Regular inspection of motor and feedback cables helps prevent intermittent faults caused by mechanical stress or contamination.
System Integration and Compatibility
The drive integrates into automation systems through its fieldbus interface or through conventional analog and digital signals. It can be combined with other Servo One drives on a shared DC bus and can operate in coordinated multi axis configurations. Because the parameter structure is common across the family, existing project data can be reused when the drive mix changes.
Selection Guidance
Selecting the correct variant depends on continuous and peak motor current, motor inductance, feedback type, required fieldbus protocol, safety requirements, maximum operating speed and available cabinet space. The 20 A rating and 400 Hz output ceiling of the SO84.020.0020.0000.2 suit medium to large servo motors and applications that combine high torque with high speed.
Conclusion
The LUST LTi Drives SO84.020.0020.0000.2 combines a 20 A power stage and a 0 to 400 Hz output range with the proven control architecture of the Servo One platform. Its feedback flexibility, integrated safety functions, shared DC bus capability and consistent parameter structure make it a practical choice for demanding industrial motion applications. For engineers specifying or maintaining high performance servo systems, this drive represents a well understood and dependable component.
