Installation manual

Danaher Motion Kollmorgen System Operation
SERVOSTAR
®
S and SERVOSTAR
®
CD Series 72
POSITION LOOP
The final control configuration is the position loop. The purpose of this loop is
to maintain motor shaft position. Like the previous loops, the position loop is
fully digital and uses resolver, encoder, and sine encoder feedback signals to
determine actual motor position. The drive can also accept a position signal
from an external feedback device (e.g., load encoder). It samples at a rate of 2
kHz and can be configured for three different modes of operation:
OPMODE 4: This mode of operation sets the SERVOSTAR up to run as a pulse
(or master encoder) follower by using the Electronic Gearing feature. The pulse
input can either be applied through the Configurable Inputs on the C3 connector
(up to 2.5 KHz max. - opto-isolated) or through the Remote Encoder Input on
the C8 connector (up to 3 MHz) on top of the drive.
OPMODE 8: This mode of operation configures the SERVOSTAR as a simple
positioning controller. Once in this mode, position commands can be given
through the serial port, through the Configurable I/O, or through the analog
input (determined by the PCMDMODE variable). The position loop has been
enhanced to a full PID controller with acceleration and velocity feed-forward
gains. Two integral gain variables have been added to limit the action of the
integral term during selected parts of the profile. This helps to minimize
overshoot and settling problems.
Using a serial command (PCMDMODE=0), the SERVOSTAR executes simple
absolute, incremental (or indexing), and homing motion profiles. This is done
either by direct commands through the serial port (MI, MA, MH) or by pre-
configuring a profile in memory to be used in conjunction with the Configurable
I/O (MASPEED, MISPEED0-3, MAPOS, O1, O1MODE, INx, INxMODE).
Using an analog command (PCMDMODE=1), the SERVOSTAR scales the
analog input (GEARI, GEARO) to establish a wide range of relationships
between an analog input adjustment and a corresponding shaft movement.
Homing types (HOMETYPE) are available that home to a particular analog
input level (and position count), triggering either through the Configurable
Inputs or the Remote Enable.
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 SERVOSTAR also operates in the position mode when the drive is in the
hold position state (HOLD = 1).