LTI Drives SO84.008.0020.1070.1 Servo Controller
The LTI Drives SO84.008.0020.1070.1 is a servo controller from the Servo One family, a platform developed by LUST Antriebstechnik and later marketed under the LTi Drives brand. In French documentation the device is often described as a variateur, a term that covers variable speed drives and servo controllers. The ordering code identifies a unit in the lower medium power segment of the range, suitable for axes that require accurate speed, torque and position regulation.
The Servo One platform is known for its consistent control architecture, which allows commissioning procedures, parameter structures and diagnostic concepts to remain the same across different power ratings. This consistency is valuable for machine builders that use several axes in one machine. Engineering data can be reused, spare parts planning is simplified, and maintenance teams can work across the drive family without relearning the toolchain.
Product Overview
The SO84.008.0020.1070.1 operates as a single axis servo controller. It converts a three phase mains supply into a controlled output voltage and frequency that drives a servo motor. The internal power stage uses pulse width modulation with a high switching frequency, producing smooth current waveforms, low torque ripple and quiet motor operation. The control core executes current, velocity and position loops in a closed cascade, with each loop independently tunable to match the mechanical characteristics of the connected load.
The unit is intended for cabinet mounting and can be installed alongside other drives in a multi axis arrangement. Shared DC bus operation allows braking energy from one axis to be used by another, improving energy efficiency and reducing the load on braking resistors. The drive supports both rotary servo motors and, in appropriate configurations, linear motors, giving machine designers flexibility in how axes are implemented.
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 monitoring functions continuously evaluate current, voltage, temperature and following error. When a limit is exceeded, the drive triggers a defined fault response and disables the output stage, 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, which is important for moderate 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. A dedicated output for a motor holding brake is available for vertical axes. The unit is protected against overcurrent, overvoltage, undervoltage and overtemperature conditions, and it includes an electronic motor overload model that estimates winding temperature without additional sensors.
Technical Specifications
The SO84.008.0020.1070.1 is designed for a three phase mains connection in the 400 V class. Its power stage provides sufficient output for small and medium sized servo motors and moderate inertia loads, with short term overload capability for acceleration peaks. The output frequency range extends across a wide band, supporting both standard servo motors and higher speed spindle applications. 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 or through conventional analog and digital signals, depending on the configuration. Supported fieldbus protocols across the Servo One family include EtherCAT, PROFIBUS, PROFINET, CANopen and EtherNet/IP. This flexibility allows the drive to be used both in centralized motion architectures and in decentralized architectures where the drive performs interpolation tasks locally.
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 can be tuned with adjustable gain, integral time and filter settings, so that resonance in the mechanical train can be suppressed without sacrificing bandwidth.
Because the drive supports both rotary and linear motors, it can be applied to direct drive axes as well as conventional geared arrangements. This versatility reduces the number of different drive types a machine builder needs to stock and maintain. The modular configuration coding system means that a single base platform can be adapted to different feedback types and fieldbus systems by selecting the appropriate ordering code.
Application Areas
The SO84.008.0020.1070.1 is used in machine tools for feed and auxiliary axes, in packaging machinery for film feed, cutting and sealing, in printing and converting equipment for register and tension control, and in handling and robotics systems for pick and place, gantry and rotary indexing tasks. It also appears in textile machinery, plastics processing equipment and general automation systems where accurate speed and position control are required.
Installation and Commissioning
Installation begins with verifying the mains voltage, the motor rating and the feedback type. The drive must be mounted vertically with sufficient clearance above and below to allow convection cooling. Shielding of the motor cable is essential for electromagnetic compatibility, and the shield should be bonded to the cabinet ground at both ends using a large contact area. Motor and feedback cables should be routed separately from mains and signal cables to reduce interference.
Commissioning typically starts with entering the motor data, either manually or by selecting a stored motor dataset. The feedback system is then checked for correct direction and resolution. After the current loop is verified, the velocity and position loops are tuned using step response tests or automatic tuning routines. Finally, the fieldbus parameters, limit values and fault responses are configured and stored in non volatile memory.
Maintenance and Diagnostics
The drive includes a diagnostic memory that records fault codes, operating hours and critical parameter values at the moment of a trip. Regular maintenance consists of checking cabinet cooling, verifying terminal torque, inspecting cable shields and clearing dust from heatsink fins. Fan units, where fitted, should be replaced according to the recommended service interval.
System Integration and Compatibility
The SO84.008.0020.1070.1 integrates into automation systems through its fieldbus interface or through conventional analog and digital signals. It can be combined with other drives in the same family on a shared DC bus, and it supports master slave torque distribution for mechanically coupled axes. Because the parameter structure is consistent across the Servo One range, engineering effort can be reused when additional axes are added to a machine.
Selection Guidance
When selecting this drive, the key considerations are continuous and peak motor current, motor inductance, feedback type, required fieldbus protocol, safety requirements and the available cabinet space. The SO84.008.0020.1070.1 suits small and medium sized servo motors and moderate inertia loads. For higher current requirements, other members of the same family provide larger ratings while retaining identical control functionality and parameter structure.
Conclusion
The LTI Drives SO84.008.0020.1070.1 is a servo controller from the Servo One family that delivers precise closed loop control in a compact package. Its flexible feedback support, integrated monitoring and consistent parameter structure make it suitable for a wide range of industrial motion tasks. For engineers designing or maintaining compact servo systems, this drive remains a practical and well understood component.
