Universal File Format Import Driver for LabVIEW and DIAdem

Overview

For Engineers who analyze Sound and Vibration data and work with Universal File Format files, this driver provides connectivity with DIAdem and LabVIEW. Unlike other Analysis/Acquisition packages, DIAdem and LabVIEW can be easily extended to support virtually any specific file format.

Contents

Introduction

Universal file formats were initially developed in the later 1960s and early 1970 by the Structural Dynamics Research Corporation (SDRC) to standardize data transfer between computer aided design (CAD) and computer aided test (CAT) software packages.

The Universal File Format driver will let you import UFF 58 (binary and ASCII) files into DIAdem or LabVIEW. The driver is based in National Instruments USI technology, which give you the advantage of having a common driver that will work with all application software that support USI.

Universal File Format 58


The Universal File Format 58 has been the defacto standard for the experimental dynamics community, specially in the area of modal analysis. The format defines a header that contains general information about the data contained in the file (function type, response direction, etc) as well as channel specific information (channel name, units, data type, etc). To reduce storage space as well as loading time, the binary universal file format was introduced. This files contain the same information as the ASCII type, the only difference is the way the data values are stored.

The Universal File Format header is divided in records 80 characters long that contain one or more fields of information. The first record is a delimiter and has to have -1 in the first six columns. The file also needs to have a stop record at the end of the data values with the same form as the first record. The second record specifies the storage type of the data values: 58 for ASCII and 58b for binary. This particular record has more fields on the 58b specification since it contains binary data specific information such as byte order.

The format support the definition of the Abscissa channel in terms of abscissa minimum and abscissa increment values or by specifying each abscissa value. If the data is evenly spaced, you can save disk space by storing your abscissa channel implicitly. The format also supports the storage of complex data for the Ordinate channel as well as the definition of a Z channel and a Ordinate denominator channel. This features are not supported by the Universal File Format driver.

USI Technology


The Universal Storage Interface technology is based in a layer of software called the USI kernel that, based on a plug-in architecture, gives you a common interface to the application software to import/export different type of data storages. This means that the same plug-in will work with all the application software that supports USI ( LabVIEW 8.2+ and DIAdem 10.1+).



The Universal File Format plug-in is based on the TDM data model. This model defines a set of properties for the data set, for channel groups and for channels. The information contained in the fields of the Universal File Format are automatically mapped to TDM properties. Some fields do not have a correspondent TDM property, in which case the plug-in uses "custom properties". Custom properties are used to extend the TDM model and allows you to define your own property-value pairs.

Once that a driver is register with the USI layer, DIAdem automatically associate the registered extension with the corresponding plug-in. In the Universal File Format driver case, the plug-in is associated with the *.uff extension. To import a UFF file you only need to drag and drop the file to the data portal. To access custom properties you need to right clicking the desired category (channel group name or channel name) and choose "Select properties". In the dialog that pops up you need to click on "Display custom properties" and select which properties you want to show.




In LabVIEW, the interface VI's can be found in the Storage subpalette inside the File I/O palette. This VI's provide a common interface to all the registered plug-ins in the system. You can use Get Property.vi to access the custom properties that the plug-in defines. An example LabVIEW program is provided with the plug-in download.

Driver Download


The Universal File Format 58 driver it's based on USI technology which is supported by:
- LabVIEW 8.2 or later
- DIAdem 10.1 or later


This driver is available through the International Electrotechnical Commission DataPlugin for UFF-58.