Installation manual

Danaher Motion Kollmorgen 08/04 System Operation
SERVOSTAR S Installation M-SS-001-01 Rev. T 69
In this mode of operation, the drive can also accept an external
load feedback signal through the C8 connector (DUALFB=1). This
helps eliminate the positional inaccuracies due to gear backlash
and poor coupling by positioning according to the load’s position
(not the motor shaft’s position).
The SERVO
STAR also operates in the position mode when the
drive is in the hold position state (HOLD = 1).
7.3.3 TORQUE LOOP OPERATION
The SERVOSTAR has many internal variables that are used to
examine and dictate system operation. Many of these variables and
their locations in
MOTIONLINK are presented graphically in the
following discussions to help disclose meanings and relationships.
7.3.3.1. Serial Torque
The SERVOSTAR can be operated as a serial torque-controlled
amplifier (OPMODE 2). It receives a serial command (T) via a host
to a command generator, which in turn creates a current command
(ICMD). The current (or torque) command is 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 actual motor current is updated and the
process begins again. The following graphic is a representation of
the serial torque loop operation (refer to the VarCom Reference
Guide for details on all variables and commands).
Control Limits
IMAX (DIPEAK/ MIPEAK)
ICONT (DCONT / MICONT)
ILIM, ILIM2
FOLD, FOLDTIME, FOLDMODE
MFOLD, MFOLDDIS, MFOLDD, MFOLDT, MFOLDR
Serial Command
Command
Generator
Compensator based on
motor parameters
IA IC
IISCALE
ANOUT
1 OR 3
DVM
ICMD