Installation manual

Danaher Motion Kollmorgen Appendix C
SERVOSTAR
®
S and SERVOSTAR
®
CD Series 114
MENCTYPE 2
Encoders with A/B/I channels Some systems do not have hall channels, so this
mode tells the SERVOSTAR not to expect them. The initialization process
occurs in two steps. The first step is the 'wake-and-shake initialization process
(see MENCTYPE 3 and MENCTYPE 4 for "wake and shake" details) which
gets the commutation alignment initialized after power up. The second step
occurs when the index pulse is seen. Then, the SERVOSTAR aligns the
commutation angle according to the setting of MECNOFF. MENCTYPE 2 is
initialized using ENCSTART or performed automatically upon power-up when
the drive is enabled.
The 'wake and shake' initialization process is not required if the
marker location can be traversed without requiring the
SERVOSTAR to move the motor to traverse the marker.
MENCTYPE 3
Encoders with A and B channels only The simplest of encoders provide only
an A and B Channel. MENCTYPE 3 configures the SERVOSTAR for these
signals. These encoders provide no power-up information about where the motor
is positioned, so this information is obtained through a special initialization
process known as 'wake and shake'. When using MENCTYPE 3, initialization is
required but it is triggered by the serial command, ENCSTART.
During the initialization process, "wake and shake," the SERVOSTAR puts
current through two phases of the motor causing the motor shaft to rotate into a
"torque detent." The magnets simply align the motor shaft to a position the
SERVOSTAR understands. The motor is then rotated to the next pole position
by energizing the windings in a slightly different manner. The SERVOSTAR
then has enough information to establish an appropriate commutation angle
using the number of motor poles (MPOLES) and the number of counts for the
encoder (MENCRES).
This method of initialization has the advantage of allowing an extremely cost-
effective feedback device. However, the requirement to pull the motor into these
torque detents is subject to outside influences (such as friction) and can prevent
the motor motion from occurring very effectively or even at all! Additionally,
large inertia loads can overshoot and oscillate during this pull-in position, giving
the microprocessor false readings. These MENCTYPEs are best for systems
with specific criteria requirements such as low friction, low cost, and low
inertial loads. The amount of electrical current used in this initialization mode is
adjustable using the IENCSTART variable and may need to be adjusted to
optimize performance for large inertial loads.