Galil Motion Control DMC-18 2 Series, User Manual

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2 ● Chapter 1 Overview DMC-18x2
Standard Servo Motors with +/- 10 Volt Command Signal
The DMC-18x2 achieves superior precision through use of a 16-bit motor command output DAC and a
sophisticated PID filter that features velocity and acceleration feedforward, an extra pole filter and
integration limits.
The controller is configured by the factory for standard servo motor operation. In this configuration,
the controller provides an analog signal (+/- 10Volt) to connect to a servo amplifier. This connection
is described in Chapter 2.
Brushless Servo Motor with Sinusoidal Commutation
The DMC-18x2 can provide sinusoidal commutation for brushless motors (BLM). In this
configuration, the controller generates two sinusoidal signals for connection with amplifiers
specifically designed for this purpose.
Note:
The task of generating sinusoidal commutation may be accomplished in the brushless motor
amplifier. If the amplifier generates the sinusoidal commutation signals, only a single command signal
is required and the controller should be configured for a standard servo motor (described above).
Sinusoidal commutation in the controller can be used with linear and rotary BLMs. However, the
motor velocity should be limited such that a magnetic cycle lasts at least 6 milliseconds*. For faster
motors, please contact the factory.
The controller provides a one-time, automatic set-up procedure. The parameters determined by this
procedure can then be saved in non-volatile memory to be used whenever the system is powered on.
The DMC-18x2 can control BLMs equipped with Hall sensors as well as without Hall sensors. If hall
sensors are available, once the controller has been setup, the controller will estimate the commutation
phase upon reset. This allows the motor to function immediately upon power up. The hall effect
sensors also provide a method for setting the precise commutation phase. Chapter 2 describes the
proper connection and procedure for using sinusoidal commutation of brushless motors.
* 6 Milliseconds per magnetic cycle assumes a servo update of 1 msec (default rate).
Stepper Motor with Step and Direction Signals
The DMC-18x2 can control stepper motors. In this mode, the controller provides two signals to
connect to the stepper motor: Step and Direction. For stepper motor operation, the controller does not
require an encoder and operates the stepper motor in an open loop. Chapter 2 describes the proper
connection and procedure for using stepper motors.
DMC-18x2 Functional Elements
The DMC-18x2 circuitry can be divided into the following functional groups as shown in Figure 1.1
and discussed below.
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