Filter
Top Products
DMC-2X00 Chapter 2 Getting Started y 27
Step 9b. Connect Sinusoidal Commutation Motors
When using sinusoidal commutation, the parameters for the commutation must be determined and
saved in the controller’s non-volatile memory. The setup for sinusoidal commutation is
different when using Hall Sensors. Each step which is affected by Hall Sensor Operation is
divided into two parts, part 1 and part 2. After connecting sinusoidal commutation motors,
the servos must be tuned as described in Step 10.
Step A. Disable the motor amplifier
Use the command, MO, to disable the motor amplifiers. For example, MOA will turn the A
axis motor off.
Step B. Connect the motor amplifier to the controller.
The sinusoidal commutation amplifier requires 2 signals, usually denoted as Phase A & Phase
B. These inputs should be connected to the two sinusoidal signals generated by the controller.
The first signal is the axis specified with the command, BA (Step 6). The second signal is
associated with the highest analog command signal available on the controller - note that this
axis was made unavailable for standard servo operation by the command BA.
When more than one axis is configured for sinusoidal commutation, the controller will assign
the second phase to the command output which has been made available through the axes
reconfiguration. The 2
nd
phase of the highest sinusoidal commutation axis will be the highest
command output and the 2
nd
phase of the lowest sinusoidal commutation axis will be the
lowest command output.
It is not necessary to be concerned with cross-wiring the 1
st
and 2
nd
signals. If this wiring is
incorrect, the setup procedure will alert the user (Step D).
Example: Sinusoidal Commutation Configuration using a DMC-
2x70
BAAC
This command causes the controller to be reconfigured as a DMC-2x50 controller. The A and
C axes are configured for sinusoidal commutation. The first phase of the A axis will be the
motor command A signal. The second phase of the A axis will be the motor command F
signal. The first phase of the C axis will be the motor command C signal. The second phase
of the C axis will be the motor command G signal.
Step C. Specify the Size of the Magnetic Cycle.
Use the command, BM, to specify the size of the brushless motors magnetic cycle in encoder
counts. For example, if the X axis is a linear motor where the magnetic cycle length is 62
mm, and the encoder resolution is 1 micron, the cycle equals 62,000 counts. This can be
commanded with the command:
BM 62000
On the other hand, if the C axis is a rotary motor with 4000 counts per revolution and 3
magnetic cycles per revolution (three pole pairs) the command is:
BM,, 1333.333
Step D - part 1 (Systems with or without Hall Sensors). Test the Polarity of the DACs
Use the brushless motor setup command, BS, to test the polarity of the output DACs. This
command applies a certain voltage, V, to each phase for some time T, and checks to see if the
motion is in the correct direction.