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This command causes the controller to be reconfigured as a DMC-4050 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.

The user must specify the value for V and T. For example, the command:

BSA = 2,700

will test the A axis with a voltage of 2 volts, applying it for 700 millisecond for each phase. In response,
this test indicates whether the DAC wiring is correct and will indicate an approximate value of BM. If the
wiring is correct, the approximate value for BM will agree with the value used in the previous step.

NOTE:

In order to properly conduct the brushless setup, the motor must be allowed to move a minimum of one

magnetic cycle in both directions.

NOTE:

When using Galil Windows software, the timeout must be set to a minimum of 10 seconds (time-out =

10000) when executing the BS command. This allows the software to retrieve all messages returned from
the controller.

Step D - part 2 (Systems with Hall Sensors Only).

Test the Hall Sensor Configuration.

Since the Hall sensors are connected randomly, it is very likely that they are wired in the incorrect order.
The brushless setup command indicates the correct wiring of the Hall sensors. The Hall sensor wires
should be re-configured to reflect the results of this test.

The setup command also reports the position offset of the Hall transition point and the zero phase of the
motor commutation. The zero transition of the Hall sensors typically occur at 0

, 30

or 90

of the phase

commutation. It is necessary to inform the controller about the offset of the Hall sensor and this is done
with the instruction, BB.

Step E.

Save Brushless Motor Configuration

It is very important to save the brushless motor configuration in non-volatile memory. After the motor
wiring and setup parameters have been properly configured, the burn command, BN, should be given.

NOTE:

Without Hall sensors, the controller will not be able to estimate the commutation phase of the

brushless motor. In this case, the controller could become unstable until the commutation phase has been
set using the BZ command (see next step). It is highly recommended that the motor off command be given
before executing the BN command. In this case, the motor will be disabled upon power up or reset and the
commutation phase can be set before enabling the motor.

Step F - part 1 (Systems with or without Hall Sensors).

Set Zero Commutation Phase

When an axis has been defined as sinusoidally commutated, the controller must have an estimate for
commutation phase. When Hall sensors are used, the controller automatically estimates this value upon

DMC-40x0 User Manual

Chapter 2 Getting Started

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