Citadel Database

[jonaskj]

Hey

I am trying to learn how to use a Citadel database, but haven't found any good pages or books to help me with the basics. I am totaly green so need help to set up the database, log some data and read the data. I have made a little program with a Sinus signal that i want to try it on.

Any help will be appriciated

Johan

[rolfk]

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@jonaskj wrote:

Hey

I am trying to learn how to use a Citadel database, but haven't found any good pages or books to help me with the basics. I am totaly green so need help to set up the database, log some data and read the data. I have made a little program with a Sinus signal that i want to try it on.

Any help will be appriciated

Johan

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Citadel database itself is not meant to be used in LabVIEW directly. It is part of older LabVIEW DSC versions and the only way to log values to the Citadel database is by using the LabVIEW DSC VIs. The ODBC connector for Citadel only provides query capabilities but no way of writing to it.

However newer versions (>= 7.0) of LabVIEW DSC do use the Microsoft SQL server for data logging, a decision I don't fully understand but that is another story.

Rolf Kalbermatter

[REM1]

DSC 7.x and higher make use of Microsoft's free version of SQL Server in conjunction with Citadel for logging alarm/event data.  All other data is stored in Citadel itself and never interacts with SQL Server.

Why?

Citadel is a streaming database which is both efficient and compact when dealing with single point data.  Relational databases (like MSDE) are better at dealing with complex data, particularly when the data is comprized of clusters of strings.  The alarm/event data from DSC is just that so, rather than try and make Citadel do something foreign to its core purpose, streaming data, it was decided to make use of an add-on relational database.  MSDE was chosen because it was both free and upgradable should the need arise.

[jonaskj]

Message Edited by jonaskj on 02-06-2006 04:43 AM

[dweikel]

Why not have all the data using the MSDE engine, creating add-ons to SQL server. Many process historians (i.e. Industrial SQLServer) do this, and will actually pull the data from the OPC source, thereby eliminating the need to program the data collection.