ATI DAQ F/T C Library (v1.0.6)

The purpose of this C library is to load and parse calibration files for ATI DAQ F/T transducers, and perform the necessary calculations to convert raw voltages from a data acquisition system into forces and torques.

Neither the library itself or the sample applications provide hardware I/O. These functions must be provided by your hardware's device drivers.

If you are developing an application for the Windows environment, we recommend you use the ATIDAQFT ActiveX Automation Server or the ATICombinedDAQFT .NET assembly.

Licensing

All of the software including in this package is distributed under the MIT License:

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

http://www.opensource.org/licenses/mit-license.html

Library Files

The following files should be compiled as part of your project: ftconfig.c ftrt.c dom.c expatls.c node.c stack.c xmlparse.c xmlrole.c xmltok.c

In addition to the above files, the files "events.c", "xmltok_impl.c", and "xmltok_ns.c" are also included in this library, but are not meant to be directly compiled, as they are '#include'd into other library files.

None of these files are intended to be modified.

Sample Applications

Two sample applications are included in the Samples folder.

ftconvert.c - demonstrates configuring a DAQ F/T system and performing force/torque calculations; converts a sample set of voltages into forces and torques. calinfo.c - demonstrates retrieving information from the calibration file such as the transducer's rated loads, calibration date, and other information.

Programming Interface

The functions supported for public use are:

createCalibration - Loads calibration info for a transducer from a calibration file destroyCalibration - Frees memory allocated by a successful call to createCalibration SetToolTransform - Performs a 6-axis translation/rotation on the transducer's coordinate system SetForceUnits - Sets the units of force output SetTorqueUnits - Sets the units of torque outputEnables or disables temperature compensation, if available Bias - Stores a voltage reading to be subtracted from subsequent readings, effectively "zeroing" the transducer output to remove tooling weight, etc. ConvertToFT - Converts an array of voltages into forces and torques

These functions are documented in ftconfig.h.

You can also read information about the transducer system and calibration from the Calibration and other structures. These structures should be treated as read-only and should only be manipulated through the functions listed above. The sample application calinfo.c shows how to retrieve this information.

The general structure of an application should follow the following structure:

1. Call the createCalibration() method to load a calibration file into memory.
2. Call the SetForceUnits(), SetTorqueUnits(), SetCalibration(), and SetToolTransform() functions to configure the system.
3. Use device driver calls to retrieve an array of voltages from your data acquisition system.
4. Use the Bias() function to store a baseline reading (zero the transducer)
5. Use the ConvertToFT() function to convert another array of voltages into forces and torques. The Bias reading will be subtracted automatically.
6. Call the destroyCalibration() function to free memory allocated for the Calibration structure created in step 1.

Optimizing Your Application

The bare minimum calculations for converting voltages into forces and torques are in ftrt.c. To isolate this section of the code, simply compile ftrc.c.
This file #includes ftrc.h, but none of the other files. This can be useful, for example, in an embedded application where the configuration never changes. You can write a separate configuration program to run on a PC, which sends the contents of the Calibration.rt structure to a local copy of the RTCoefs structure in the embedded system.

Version History

1.0.6 Added support for kN-m torque units, changed reference to ActiveX server to also reference .NET assembly. 1.0.5 Moved some declarations out of .h files into .c files to avoid multiple definition errors. Added ftsharedrt.h 1.0.4 Added newlines to the ends of several files to avoid warnings when compiling with gcc. FTconfig.c was using '/t' instead of '\t' for tab character, which caused warnings under gcc, but no warnings or errors under Visual C++. 1.0.3 Added comments to ftconvert.c explaining hardware temperature compensation. 1.0.2 Fixed memory leaks 1.0.0 No changes Released 2-1-02 0.7.1 Added necessary licensing info to all files Beta released 10-5-01 0.7.0 Initial beta release; no known bugs; compiles with no errors or warnings in Microsoft Visual Studio.NET Beta released 10-2-01