Tags:
create new tag
view all tags

WCF Data Extraction

DataRay records a buffer of 64 samples which are recorded (choose "save all in buffer") into a *.wcf file. Additionally, a 'job file' is required for analysis. Open up a buffer you wish to analyse with DataRay, set the clip levels by clicking on them in the top left and setting the crosshair properties by right clicking on image. Once set, go to File>Save Job File and save the job file where you wish. DataRay will use the settings from this job file when analysing the data. A typical job file with freely orientating crosshairs which snap to the peak location is provided here. Clip level 1 is 13.5% and clip level 2 is 4 Sigma. ISO11146 is used also.

DataRay's Active X library can be used in LabView to extract data from the .wcf buffer files recorded by DataRay. therefore, a LabView VI was written to extract useful information; average it for each buffer of 64 samples (this number is fixed by DataRay); calculate the standard deviation and export it to a text file. The VI can be dowloaded from here. The output columns are as follows:

Column Value OCX Index
1 Position NA
2 % Peak 182
3 $\pm $ NA
4 ISO11146 Major Axis 225
5 $\pm $ NA
6 ISO11146 Minor Axis 226
7 $\pm $ NA
8 UC1 77
9 $\pm $ NA
10 VC1 81
11 $\pm $ NA
12 UC2 78
13 $\pm $ NA
14 VC2 88
15 $\pm $ NA
16 Angle 227
17 $\pm $ NA

NOTE: Data files should be named as ###.##mm.wcf to ensure compatibility with the VI. The VI will readout ###.## as the first column.

These settings were found using DataRay 7.00Te (iDataRay is the name on the website). UC1 refers to minor axis - clip level 1. When the crosshairs are "forced to 0 degrees," this will be the horizontal axis. V refers to the major axis and in the case of 0 degrees is the vertical. Angle is the angle between the major axis and the 12 o'clock position (clockwise).

A single parameter VI was also made and is available here.

These OCX indices are different from the interfacing manual on the website which is often wrong. By creating an Active X button control and looking through the properties a close index can be found. The correct OCX index may be offset by one so testing of the parameter to be extracted is vital. In some cases, the indices were considerably different from the published values. Fig. 1 shows a screen capture of OCX index 77 being extracted and the same sample from a buffer in DataRay. This parameter (UC1) was advertised as 78 in the manual. The ISO standard parameters were supposedly 218, 219, 220 which is obviously wrong.

Dataray parameter 77 which is supposedly 78

Edit | Attach | Watch | Print version | History: r3 < r2 < r1 | Backlinks | Raw View | Raw edit | More topic actions

Physics WebpagesRHUL WebpagesCampus Connect • Royal Holloway, University of London, Egham, Surrey TW20 0EX; Tel/Fax +44 (0)1784 434455/437520

Topic revision: r3 - 28 Oct 2021 - LaurieNevay

 
This site is powered by the TWiki collaboration platform Powered by PerlCopyright © 2008-2021 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding RHUL Physics Department TWiki? Send feedback