HandyBase for statistical processing of test results
A test database solution, HandyBASE, is available. HandyBASE is a powerful client/server system for monitoring of statistical information produced during production testing of various devices. The server is built on top of a Microsoft Access 7.0 database, which contains all statistical information on the devices. You can use the client to view the statistical information on screen or you can print a hardcopy on a printer.
HandyBASE has been designed with a high degree of flexibility. It executes the system over a local network. While the server is running on a particular PC on the local network, the client can be executed from any other PC on the network. However, the client can be executed on the server as well. There are no restrictions on the number of clients accessing the server simultaneously.
Some of the features of HandyBASE include:
- Handling of multiple clients.
- HandyBASE allows any number of clients to access the server simultaneously. However, the response time from the server depends on the number of clients trying to access the server simultaneously.
- Logging activities on the server.
- From a client the user can set up the logging level on the server. Logging can be
disabled completely or the user can enable logging at different levels. The logging level
determines how many details are logged. Details about transfers to a particular client
include identification (the In
ternet Protocol address) of the client involved in the transfer.
Logging activities on a client.
However, the user can also enable logging locally on a client. Note that logging on a client only includes information for that client and for transfers of statistical information between the client and the server. The local logging level determines how many details are logged.
Automatic import of test results from multiple test systems.
From a client the server can be set up to automatically import test result files produced by the production test systems. Simply set up the paths to where the server should look for test result files. Note that although the paths from the client are set up, you must type them as seen by the server. In order to import test result files from a test system the server must have network access to the test system.
Easy to use interface to set up selective criterions.
The client interface implements simple facilities to select statistical information. For example, statistical information for a specific device type can be selected over a certain period and only for certain primary IDs (PIDs) and derivatives of such primary measurements, secondary IDs (SIDs).
Generation of statistical information during import.
As HandyBASE imports the test result files produced by the production test systems, the statistical information, which is stored in the Microsoft Access 7.0 database, is automatically updated. This means that the statistical calculations are done once and for all during import of result files leaving only very few calculations to be done on requests for statistical information.
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| Example of a display of parameters (frequency sweep). The curves show the mean of a distribution as well as the±3 Sigma values. in addition, a user defined set of limiters (a Tunnel limiter and a Window limiter are displayed). |
Fast access to the statistical information.
Since the statistical calculations are handled during import of result files, HandyBASE turns out to be a very quick database system with very low response times, even for complex requests which you might expect to be very time consuming.
Selection of information about individual devices.
HandyBASE enables the user to select the measurement results for a particular device.
Suppose a situation where a production test system has been used to perform a set of sweep
measurements in the frequency domain for a group of UUTs. When the result files have been
imported into
the Microsoft Access 7.0 database, HandyBASE enables the user to get exact curves of the
sweeps for each device. To restrict the amount of disk space consumed by curves, a limit
for how long a curve shall be maintained in the database can be set up.
Selection of statistical information based on several devices.
Statistical information for a group of devices can be selected based upon the type or
upon specific special orders. Most of the statistical information resides as
pre-calculated information in the Microsoft Access 7.0 database, thereby decreasing the
response time of the server significantly. The calculations are done once and for all
during automatic im
port of the production test result files.
On-screen presentation of statistical information.
The on-screen presentation enables the user to view all statistical information directly
on a screen including sweeps, key parameter histograms, and error histograms.
Hardcopy presentation of statistical information.
The hardcopy presentation enables you to produce nice looking and well-arranged reports of
the statistical information including sweeps, key parameter histograms, and error
histograms, etc.
Reporting Types
A number of predefined reports are available for data acquired during testing. The report generation is easy, using a parameterised setup for generation. If reports are to be generated, which do not already form part of the standard offerings, a new report generator can be programmed in LabVIEW. Examples of already existing standard reports are given below.
Histogram and Sweep Reports
A user defines the contents of a report by selecting the relevant information from the window. One can view the contents of the reports directly on the screen before they are sent to a network printer.
In addition to displaying data in various processed forms, limiter functions can also be activated for the processed data. As a result it is possible to apply limiter conditions to processed data similar to what is done in a measurement situation, where typically only one device is in question. In HandyBASE, the limiter subsystem, CALC, is called for the parameter of interest. In the example of Figure 16, a Window limiter may be active for searching for a local minimum in the window. The parameter is the "mean-of-the-amplitude" versus frequency. The mean can be that of hundreds or thousands of measured units. Similarly Point limiters and Tunnel limiters can be activated for the calculated data.
| The display shows a histogram distribution of averaged data for a given parameter. Some measurement data appears far off the main part of the distribution. The point limiters are shown for the limits applied to testing. |  |
Various filter functions are available for the display. It is possible to use such filter functions to amplify the main trends of the populations in question. A Noise filter will for example remove all data below the lower limit and above the upper limit (concentrate on all accepted units), whereas a Limit filter will filter off data that is not in the vicinity of the lower limit or the upper limit. The filter functions can be combined as well.
Key Parameter Reports
Statistics on measured parameters can be obtained using the "key Parameters" window. From this graphical user interface the relevant data can be selected and the results are shown on the monitor, or can be printed out.
Error Reports
This type of reporting allows the user to generate a report on the distribution of defects, say as a function of each production week. Other display capabilities are also available with this type of reporting.
The selection of data for a histogram or sweep type of report is done from a pop-up
menu.
Miscellaneous
A number of other reporting functions is available as standard features. In addition, microLEX also generates company specific presentations tailored to needs of the companies. It is possible for a user to generate his/her own presentations by programming this in the associated LabVIEW code. Priority access allows the individual user organisations to define, who should have access to, and be allowed to, modify such presentation interfaces of the database.
