Data Loggin using shared variable and the Citadel

[IPG1320]

Using Labview 8.2.1 and Labview DSC module 8.2

Currently using the shared variable engine to log Thermocouple and pressure data to the Citadel database. Typically I use a VI employing the Read Trace.vi to view the trace in a chart format within 48 hours of the data  being logged.

About 2 months I found that VI to be unresponsive. Using max I invesitgated the data and found there to be gaps in the data stream ranging from 10 min to 2 hours, these occured on various trace,s at various time. I was able to use max to view the traces graphically.

The VI I use to view the data has since worked, and appears to only hang when I try to pull a data set that includes missing data.

Today just out of curiosity I decided to use the VI to pull one of these old data sets expecting it not to work, but it did. The chart appeared, complete with gaps.

My question is this:

Does the Citadel preform periodic maintenace that could have allowed the Read Trace.vi to work after a period of time?

Is there a known reason why these data gaps would appear?

Thank you!

[Ben]

The gaps are there on pupose to enunciate where logging was active or not.

I do not know of any automatic operations within Citadel that would introduce the gaps.

Archieving of the DB does require shutting down the DB so if you have some auto-archieve happening, that would explain the gaps.

Aside from that, make sure you are using the 8.2.1 version of DSC since the 8.2 version was really funky.

Ben

[IPG1320]

-I do not know of any auto-archiveing that would be happening, is there somewhere I would look to check that setting?

-The automatic function I was asking about wasn't one that introduced the gaps, but one that would in some way change the database so that the  Read Trace.vi that doesn't initally work, would several days later.

- I have been unable to locate a copy of the 8.2.1 DSC module

Thanks, Bruce

[Ben]

None that I know of.

Sometimes you may be able to find a message in the System log (Windows >>> Control Panel >>> Admin tools) that will give you a clue.

Ben