Galil DMC-21x3, Руководство пользователя

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64 • Chapter 10 AMP-20542 DMC-21x3 Accessories
Operation
Brushless Motor Setup
Note: If you purchased a Galil motor with the amplifier, it is ready for use. No additional setup
is necessary.
To begin the setup of a brushless motor, it is first necessary to have communications with the
motion controller. Refer to the user manual supplied with your controller for questions
regarding controller communications. Connect the encoders and motor leads to the amplifier,
then configure the controller and amplifier in software. This first involves taking all appropriate
safety precautions. For example, set a small error limit (ER*=1000), a low torque limit (TL*=3),
and set off on Error to 1 for all axes (OE*=1). Review the command reference and controller
user manual for further details. Now it is safe to power the amplifier.
The controller has been programmed to test whether the Hall commutation order is correct. To
test the commutation for the X axis, issue the BS command. The default for the BS command is
BSn=0.25,1000 which will send 0.25 volts to the amplifier for 1 second. BSX=0.5,300 will
issue 0.5 volts from the controller for 300 milliseconds on the X axis. It may be necessary to
issue more voltage to create motion. The controller will attempt to move the motor through one
revolution. If the motor is unable to move, hall transitions are not correct, or the feedback
polarity is reversed, the controller will return suggestion to the terminal response window
regarding the problem and solution. After making any necessary changes to the motor phase
wiring, confirm correct operation by re-issuing the BS command. Once the axis is wired
correctly, the controller is ready to perform closed-loop motion.
Brushless Amplifier Software Setup
Select the amplifier gain that is appropriate for the motor. The amplifier gain command (AG)
can be set to 0, 1, or 2 corresponding to 0.1, 0.25, and 0.5 A/V. In addition to the gain, peak and
continuous torque limits can be set through TK and TL respectively. The TK and TL values are
entered in volts per axis. The peak limit will set the maximum voltage that will be output from
the controller to the amplifier. The continuous current will set what the maximum average
current is over a one second interval. As an example, if the gain is set to 0.5 A/V with a torque
limit of 3 (TLn=3) this will allow the amplifier to output no more than 1.5 amps of current on
the specified axis.
The user can choose between Inverter (AU0 or AU1) or Chopper mode (AU0.5 or AU1.5). For
motors with inductance between 200 and 500
μ
H, use Chopper mode, for motors with
inductance greater than 500 mH, use inverter mode. Note that chopper mode inherently has the
potential to cause instability at rest depending on tuning and axis characteristics. The user can
also select between normal (AU0 or AU0.5) or high current bandwidth (AU1 or AU1.5). As an
example of the AU command, if the X axis uses normal current loop bandwidth and chopper
mode, and the Y axis uses high current loop bandwidth and inverter mode, the setting would be
AU 0.5,1.
The bandwidth of the current loop for a specific combination can be determined by the AW
command with the basic amplifier parameters. To calculate the bandwidth for the X axis, issue
AWX=v,l,n where v represents the DC voltage input to the card, l represents the inductance of
the motor in millihenries, and n represents the AU setting.
Note:
For most applications, unless the motor has more than 5 mH of inductance with a 24V
supply, or 10 mH of inductance with a 48 V supply, the normal current loop bandwidth option
should be chosen. AW will return the current loop bandwidth in Hertz.