Chapter 2 Configuration and Installation
NI 7350 User Manual 2-6 ni.com
software to work with this type of system, refer to the NI-Motion User
Manual.
When connecting to a drive that does not perform the sinusoidal
commutation, the NI 7350 commutates the first two phases and the servo
drivedetermines the third. Therefore, two DAC outputs are required
peraxi s. Refer to the Measurement & Automation Explorer Help for
Motion for information about configuring the NI-Motion software for
brushless servo motors.
Connecting the Hall Effect Sensors
Before the NI 7350 can calculate the commutation values, some form of
initialization is necessary to determine the initial commutation phase angle
of the brushless motor each time the controller is powered on, reset, or
reconfigured.
One method of initialization is to connect Hall effect sensors to detect the
commutation phase angle of the motor. You can specify how the system is
configured in MAX.
Tip If you do not connect Hall effect sensors, you can set the commutation phase angle
directly, or through a process called shake and wake. Shake and wake requires moving the
motors to the 0ยบ angle and setting the commutation phase angle to match.
It is important to correctly connect the Hall effect sensors to the controller
so that the sensors accurately determine the commutation phase angle.
Complete the following steps to connect the Hall effect sensors.
1. Locate the Hall effect sensor phase sequence diagram that applies to
the motor you are using. The manufacturer of the motor should provide
this diagram with the motor documentation.
Note The NI 7350 controller can use Hall effect sensors having three sensor outputs per
motor. Each output is 120 degrees out of phase from the previous output.
2. Wire the Hall effect sensors based on the Hall effect sensor phase
sequence diagram for the motor and Figures2-1 and 2-2.
Match the Hall effect sensor phase sequence diagram for the motor
with one of the diagrams in Figures 2-1 and 2-2. The diagrams on the
left represent the diagram supplied with the motor. The diagrams on
the right represent the expected inputs to the UMI or NI 7350. The
arrows in the middle show the correct path to wire the Hall effect
sensor outputs into the UMI or NI 7350 inputs.