If more flexibility is needed in order to customize or automate the retrieval process, you can programmatically access the trace data in Citadel through a LabVIEW API, ODBC driver and web services.
LabVIEW DSC Module
The LabVIEW Datalogging and Supervisory Control (DSC) Module includes VIs to read historical data from Citadel. It also makes available run-time retrieval selections by providing VIs to return the available databases and traces that can be polled for data. After retrieving the logged data, you can use LabVIEW’s processing tools to manipulate trace data, compute statistics, query alarm and events, or convert the data into spreadsheet format.
Figure 3: Using LabVIEW's DSC Historical VIs
Citadel ODBC Driver
To facilitate sharing data, Citadel includes an ODBC driver that enables you execute data retrieval directly into third-party applications. The Citadel 5 ODBC driver is compliant with SQL 92 and ODBC 2.5 standards therefore any third-party client software that follows these standards can retrieve data from a Citadel database.
In addition, ADO clients can use the ODBC driver through the Microsoft OLE DB Provider for ODBC Drivers to access the Citadel 5.2 and later databases.
An example of using the ODBC driver with Microsoft Excel is implemented in the tutorial: Accessing Citadel 5 Data with Microsoft Excel 2007.
Citadel Web Services
If the data access is needed across long distances Citadel exposes web services to allow for more open and standard way to communicate over the Web. Through the structure of the URL calls to the server hosting Citadel’s web services, a user can retrieval information about the available databases and traces as well as pull trace data. It is important to note that web programming language knowledge is required to successfully build an interface to visualize the data retrieved from Citadel through a web service.
For more detailed information about the web services Citadel provides refer to the LabVIEW Help: Accessing the Citadel Web Service.
Learn more about web services and how they can be created in LabVIEW: Web Services in LabVIEW.