Servosila-SC-25-Brushless-Motor-Controllers

Operation Modes & Capabilities
Servosila SC-25 Brushless/Brushed Motor Controllers are capable of controlling motors in
several different ways called “modes”. The controllers switch from one mode to another upon
receiving commands sent via CAN or USB 2.0 by a control computer/PLC.
1. “Electronic Torque Control”. In this mode, the system tightly controls a prescribed
current flowing through the motor. This defines torque with which a brushless/brushed
motor actuates its payload. This mode would typically be employed whenever what
matters is torque rather than speed of the motor, for example, in a test/diagnostics
equipment, or in a highly dynamic walking robot application.
2. “Electronic Speed Control (ESC)”. In this mode, the Servosila controllers maintain a
constant commanded speed of rotation of the motors’ shafts under an influence of varying
external forces. The controllers automatically increase or decrease torque in response to
perturbations of external loads thus keeping the speed of the drive constant. This mode is
often used when actuating pumps, conveyor belts, thrust drives, mobile chassis, and in
many other applications.
3. “Servo Control”. In this mode, the controller turns a brushless or a brushed motor into a
servo motor capable of holding a commanded position (with or without a gearbox). Upon
receiving a servo command, the controller first moves the drive’s output shaft to a
specific commanded position (angle), and then holds the position under an influence of
external forces that try to disturb the balance. An encoder is required in this mode to
measure absolute position of the drive’s output shaft. The encoder can be connected to the
controller via one of available encoder interfaces (BISS-C, SSI, SPI, PWM, Quadrature).
Up to 20bit of angular precision is supported. The servo control mode is widely used in
applications ranging from servo drives of robotic arm manipulators, to CNC machines, to
robotic warehouse systems.
4. “Direct Drive”. In this mode the controller directly positions magnetic fields inside a
brushless motor, and achieves the highest possible precision of positioning accuracy. This
mode is often used with electric drives that do not have a gearbox (thus the name).
Typical applications include computer vision systems, CNC machines, linear motor
actuators, - all those applications where use of a gearbox is avoided to minimize
backlash-related issues that affect positioning accuracy. A brushless motor operated in a
direct drive mode is much better than a more traditional stepper motor.
5. “Brake”. The controllers implement an energy-efficient “parking brake” mechanism that
blocks a brushless motor’s motion. This is achieved without a need for an external
braking mechanism. In this mode the controller monitors position of a brushless motor’s
rotor using either Hall sensors or an encoder, and makes energy-efficient adjustments to
the magnetic field inside the motor in such a way that rotation of the output shaft is
blocked. The built-in braking mechanism comes handy in applications where motion may
need to be stopped and then put on a brake, - such as a conveyor belt or a mobile chassis.
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