Software
Unity Framework
GDS Unity Interface
This helpsheet explains the base features of GDS’s Unity Interface
Introduction
Unity is the latest release of control firmware from GDS Instruments. With improvements in accuracy and stability, it has been developed with the aim of easing the system’s control from the User’s perspective while making the machines more reliable.
GDSLAB Unity User Interface
Changes to the Classic GDSLab User Interface
From a user point of view the only noticeable change will be a graphical interface in GDSLab’s Object Display. It offers additional options and features, which will be discussed in the next Sections of this Helpsheet.
Please note, that options enabled are system dependant and some of them may only be accessible on specific GDS equipment.
The Transducer Window
The transducer window can be accessed by left-clicking on the transducer icon in the GDSLab Object Display or on its corresponding CP icon.
Set Target tab functions:
Specify a target value for a transducer,
Check the current position against the targeted value and the position of limits.
Modify a limit targeting rate for a given transducer.
The firmware won’t allow putting values higher than the maximum rate pre-defined by GDS).
Stiffness tab functions (load cells only):
The Stiffness tab allows for improved control if very stiff samples are used during the test.
Dynamic Relative Stiffness allows to overwrite the “Stiffness Estimate” typically used it GDSLab dynamic modules.
Static Relative Stiffness regulates load control for object display and all non-dynamic test modules
Stiffness estimate for dynamic and static performance is directly related, so a value giving a good dynamic performance would also ensure stable static behaviour.
You can consult the article https://gdsinstruments.atlassian.net/l/c/QKFRJqnc for more information on how to use Stiffness Estimate.
Config tab functions:
Apply/remove offsets (using the “@” and “!” buttons),
Specify a minimum and maximum limit at which the test will stop.
Change the sensitivity of a transducer (if it was replaced or re-calibrated),
Check the maximum limits of the system which were per-defined by GDS
Select an option to stream live data of the transducer readings by ticking the “Real Time Graphs” box.
The bar at the bottom of the window shows the current position of the transducer in relation to its limits.
The transducer calibration settings section of this tab may be locked for editing, depending on the transducer type. To unlock this section please contact support@gdsinstruments.com
Unity Driver Window
The Unity Driver Window can be opened by left-clicking the image of the device in Object Display.
Transducer Manager
The Transducer Manager Tab lists all of the transducers connected to a Unity device, showing their current readings, assigned Channel # and allowing the User to apply/remove offsets (using the “@” and “!” buttons).
Real Time Graphs can also be enabled here for each channel, by ticking the RT Graph checkbox.
The list can be sorted by channel number (by clicking on #) or by channel name (by clicking on “Transducer Details”) in the header bar.
Waveform control
The Waveform Control Tab allows the user to select the type of waveform needed for their dynamic cyclic tests. All of the GDS devices capable of performing dynamic tests are pre-programmed with a sinusoidal waveform with the possibility of upgrading to trapezoidal waveform (AS-AG), Haversine waveform (AASHTO) or custom User-defined waveforms.
For more information please refer to GDS Helpsheet 196 – Custom Waveforms for Unity Devices.
System
The System Tab allows the User to “Connect/Disconnect” a Unity device and “Reset” it if needed.
The System Log saves all of the information about the system such as requested dynamic trajectories, errors and fault messages.
The GDSLab Error Queue saves all of the errors reported by the firmware. If the transducers in GDSLab Object Display are showing “Error” instead of a numerical reading, please make sure the cause of the error is resolved and Error Queue is cleared, before pressing the “Read” button in GDSLab.
Extend / Retract
The Extend/Retract Tab allows the User to position the machine prior to the test. This can be done by moving at a constant rate unlit the Stop button is pressed. Please note, that the Extension/Retraction rate can be modified using the dimensionless relative factor of rate below the buttons, however, the machine will not move faster than maximal speed pre-defined by GDS.
Dynamic
This tab controls various settings related to dynamic testing:
Real Time Graphs
Resample rate - defines the rate at which data is plotted (min. 0,002 sec)
Start Streams - Generates real time graphs for all transducers which have that option enables
Stop Steams - Stops collecting real time transducer data (but the graph windows will remain open until manually closed)
Graph Max History
History Duration - sets the time limit for plotted data. Data older than this value will be erased from the graph and replaced by new data
Unlimited Duration - tick this option to prevent data old data from being removed from the graph
Live Schematic - Applicable only for TTA Systems, displays a diagram with the position of all 4 actuators
Dynamic Tab - Lead In/Out Options
Sine waves on standard GDS systems have an instantaneous velocity (infinite acceleration) requirement at the start/end of waveforms that are physically impossible. GDSLAB test modules have default lead in/out settings to address this, but for some specimens, it may be required to adjust these settings manually.
Lead In - Applies a linear ramp scalar to the wave amplitude of the specified magnitude (LIM), at the start of a dynamic wave, for the specified duration (LID). The purpose is to prevent instantaneous and physically impossible accelerations being commanded (and the oscillations from un-modelled dynamics that result)
Lead Out - Applies a linear ramp scalar to the wave amplitude of the specified magnitude (LOM), to the end of a dynamic wave, for the specified duration (LOD). The purpose is to prevent an instantaneous acceleration (deceleration) at the end of a waveform (and again oscillations that may occur due to an impossible 'instant' stop being commanded).
During normal operation, these options are not needed. GDS Support will advise you on their use if required.
