Installation manual

Danaher Motion Kollmorgen System Operation
SERVOSTAR
®
S and SERVOSTAR
®
CD Series 74
ANALOG TORQUE
The SERVOSTAR can be often configured to operate as an analog torque loop
controller (OPMODE 3). In this case, the current loop receives its input from the
analog-to-digital (A/D) conversion system. After conversion, the input
command signal is processed through an algorithm which adjust the signal
(ANOFF, ANDB, ANZERO), filters it (ANLPFHZ) and then scales it
(ISCALE), before developing the current command (ICMD). The current (or
torque) command is then checked against peak (IMAX, ILIM) and continuous
(FoldBack features, ICONT) current clamp limits.
Sinusoidal commutation modulation is added to the command and then fed to
the three-phase current loop regulator, which calculates a current error. This
error is then fed through a digital pole-placement compensation algorithm. The
output of the compensator is converted to a PWM signal and fed to the power
transistor bridge. The power bridge uses the high voltage DC BUS Module
(typical 325 VDC bus) to supply the required current to the motor windings. The
actual motor current is updated and the process begins again.