Windows Servo Design Kit (Wsdk) - Galil Motion Control DMC-18 2 Series User Manual

Figure 4.6 - Controller Communications Method Dialog Box
Interrupt Communications Method
The interrupt method overall is the most efficient of the three methods. The software communications
method uses a hardware interrupt to notify the application that a response or unsolicited data is
available. This allows for greater efficiency and response time, since the drivers do not have to "poll"
the buffers for the data. Additionally, the interrupt method allows for data record caching.
The interrupt method uses bus level interrupts (IRQ) from the controller to notify the PC that data is
available. This requires that the Controller be configured with a valid interrupt line. For DMC-18x2
controllers the interrupt is configured automatically. Firmware version 2.0m (and greater) is required
for the "communications interrupt" method to be available. For complete information on the different
communications methods, select the More Info button on the Communications parameters dialog box.
Stall Thread and Delay Thread Methods
Users can also choose between "Delay" and "Stall" methods. These two methods are available for the
DMC-18x2 controller and affect how the software "waits" for a response from the controller when a
command is sent. If a controller is configured with the "Delay" method, the thread waiting for a
command response gives up its time slice, allowing other processes running on the operating system to
proceed. This method can slow communication, but results in negligible CPU utilization. The
second method, the "Stall" method, uses the opposite strategy. The thread that performs I/O with
the controller maintains ownership of the CPU and polls the controller until a response is
received. This approach is essentially the same method employed in previous versions (< V7) of the
Galil communication DLLs and drivers. While the "Stall" method does not have to wait for its thread
to become eligible for execution, it does result in
controller.

Windows Servo Design Kit (WSDK)

The Galil Windows Servo Design Kit includes advanced tuning and diagnostic tools that allows the
user to maximize the performance of their systems, as well as aid in setup and configuration of Galil
controllers. WSDK is recommended for all first time users of Galil controllers. WSDK has an
automatic servo tuning function that adjusts the PID filter parameters for optimum performance and
displays the resulting system step response. A four-channel storage scope provides a real-time display
of the actual position, velocity, error and torque. WSDK also includes impulse, step and frequency
response tests, which are useful for analyzing system stability, bandwidth and resonances. WSDK can
be purchased from Galil via the web at http://store.yahoo.com/galilmc/wsdk32.html.
Features Include:
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44 ● Chapter 4 - Software Tools and Communications
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Automatic tuning for optimizing controller PID filter parameters
Provides impulse, step and frequency response tests of actual hardware
Four-channel storage scope for displaying real-time position, velocity, error and torque
Displays X versus Y position for viewing actual 2-D motion path
Terminal editor and program editor for easy communication with the controller
100% CPU utilization while communicating with the
DMC-18x2