The servo converter is single-quadrant (irreversible) converter with four control modes. Selection of operating mode can be made by DIP-switch located on the servo converter board. PI-controller adjustment produced by variable resistors located on front board.

Torque control mode.In this mode servo converter operate as motor armature current controller. If set analog reference in range of 0 to 10 volt, armature current and motor shaft torque will change from zero to maximum.

Speed control mode with tachogenerator. In this mode servo converter operate as speed controller of motor shaft rotation with speed feedback. Sensivity of feedback input from tachogenerator can be set by jumper position, or fine tune by adjustable resistor.

Speed control mode with losses compensation in rotor circuit (I*R) allows to build electric drive systems without external feedback sensor. Electric drive in this mode can be used in cases where there is no need to work at the creeping speed.

Electric drive excitation current control mode. This mode is for the construction of two-zone electric drive, operating with servo converter of armature circuit (for example, XDC 200 series or any other). This mode provides electric drive excitation current stabilization, when operating in first zone and transition to the second zone when the armature voltage reaches the nominal value. Servo converter ensures field current monitoring. When field circuit breaks, "enable" and "operating" signals are removed to switch off servo converter armature circuit and avoid electric motor overrun. Also in this mode servo converter provide discrete signal n=0 when electric motor shaft speed is close to zero.