BSX
=
2,700
will test the X 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.
If Hall Sensors are Available:
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.
If Hall Sensors are Not Available:
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.
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 reset of the controller. If no hall sensors are
used, the controller will not be able to make this estimate and the commutation phase
must be set before enabling the motor.
If Hall Sensors are Not Available:
To initialize the commutation without Hall effect sensor use the command, BZ. This
function drives the motor to a position where the commutation phase is zero, and sets
the phase to zero.
The BZ command argument is a real number, which represents the voltage to be
applied to the amplifier during the initialization. When the voltage is specified by a
positive number, the initialization process will end in the motor off (MO) state. A
negative number causes the process to end in the Servo Here (SH) state.
DMC-1600
Chapter 2 Getting Started
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21
