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NetControl Software
NetControl, working with DigiControl,
provides a complete data acquisition and motion control package controlling up
to 8 actuator channels at a 2 kHz update rate. The NetControl
software interfaces with the DigiControl instrument
with a simple single cable Ethernet connection using the standard UDP
protocol. This powerful control system
provides all of the functions normally achieved with a combination of oscilloscopes,
data acquisition cards and controller cards.
NetControl handles the following real time
functions:
NetControl features a real time data acquisition and display interface which
may be programmed to acquire and display up to 39 channels of data arriving
from the DigiControl instrument.
Flexible display features such as preset channel setups, drag
and drop positioning, and real-time display of multiple channels (up to 39) facilitate
tuning and monitoring your motion control process. The displayed channels can include the
measured feedback data, internally generated waveform data, as well as the control
loop outputs.
Several different “control panels” are available which
facilitate different operating tasks.
A “tuning” panel allows the user to adjust the PID control parameters
to optimize performance while running different user supplied or canned
waveforms. This allows the user to
optimize the machines performance to achieve very close agreement between the
driving waveforms and the resulting force and motion profiles. A “manual” panel allows the user to jog the machines actuators
for the purposes of setup and sample insertion and extraction. This mode also provides canned (sine,
square, triangle, ramp) and arbitrary waveforms for evaluation and testing
without creating a full control program.
NetControl’s “simulator” control panel allows the user to select and run
preconfigured programs which automatically schedule waveform activities, data
acquisition activities and present on-screen gages and controls to monitor
the machines activities. Additional operating controls consist of simple button controls
to start, stop, pause and home the machines actuators. Once a sample has been loaded the start
control can be used to initiate a single cycle (monotonic) test or cyclic
tests running the desired waveform(s).
The DigiControl instrument has eight
channels of built in arbitrary waveform generation, which provide motion
control inputs to the eight PID channels.
NetControl provides the means to
conveniently and flexibly program the waveform generation process. Many powerful programming features and
utilities are included in the NetControl software.
Tests and experiments maybe run manually by downloading one or
more waveforms to the controllers waveform generators or more complex
programs may be built up which govern all eight channels of the DigiControl’s activity while scheduling data acquisition at
periodic intervals as well. Built in event control logic may be programmed to respond to
positive and negative thresholds on any of the monitored analog inputs channels. When the user programmed limits are crossed
the system may be programmed to evoke various control actions such as activating
a digital alarm or control line, or ramping the
waveforms to preset “safe” levels. In NetControl’s auto-mode a
scheduling system controls the machine’s activities based on elapsed cycle
count of the machine. Up to six
processes can be programmed to run sequentially. Each process includes a waveform template
which defines the cyclic motion required for the machines actuators, event
detection parameters which define thresholds and corresponding machine
control actions, start/stop transition behavior, and the data acquisition
requirements for that process. The
auto mode is particularly useful for setting up complex testing scenarios for
bio-mechanical simulations and component testing.
The DigiControl instrument provides
eight independent channels of PID (proportional, integral, derivative)
control. The control channels are
implemented digitally on the DSP. The
PID command signals originate from either the DSP’s
waveform generator or from set point values downloaded from the PC. The PID
loop feedback signals originate from user supplied force, pressure or displacement
sensors. Calibration and tuning databases allow the user to maintain
file based records of various operating scenarios for future reference and to
instantly reconfigure the controller to a previous state. Calibration
and tuning information is maintained and edited in easy to read tables which
include user supplied channel labeling so that the interface can customized
to a particular application. The NetControl software provides a “Tune”
mode which facilitates tuning of the PID loop parameters to optimize tracking
and performance of the attached actuators.
Once the tuning process has been completed the PID parameters may be
saved in named files for convenient recovery and duplication of the test
scenario. |
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