Error in MAX. Lifespan is multiplied by 100.

[josborne]

Hi!

I think I found another bug.

Open a new SCF file using the TCE (Tag Configuration Editor). Select CONFIGURE > HISTORICAL from the menu and change the lifespan (Days to keep historical data) to 1 day. Create a simple tag for testing and start the engine.

Now go into MAX and select HISTORICAL DATA and create a trace using the tag you juts created. You will notice that the lifespan in MAX appears as 100 days. All lifespans are multiplied by 100. Is this a bug? Do I get a prize?

OK... now I have another question? Does lifespan actually work? And if so, how? I am guessing that the old data points aren't actually deleted right away (I tested it). Are they simply over-written? When?

I tested the lifspan
feature by changing my clock to many days ahead and I was still able to access all my old data points without problem. I can't seem to get the lifespan function to work for me. Any tips?

[andreoliveira 47]

I John,

The first issue regarding the lifespan shown in Max does seem to be incorrect, however I am contacting the development group to check on that.

The second issue, I would like to know which version of DSC you are using, is that the 6.1 ?? Do you have the latest patches applied ??

Andre Oliveira
Applications Engineer
National Instruments

[josborne]

Hi Andre,

I am using DSC 6.1 and I am pretty sure that I have the latest patches for DSC and logos.

I am not 100% sure if the lifespan function doesn't work... but my initial test didn't seem to immediately work. I do need to test it some more... but could you tell me more about how the lifespan function works? For example:

Does citadel immediately delete old data? Or does it wait until it has some "free" processor time? Is the data permanently deleted? Or is it overwritten? If overwritten, then is the data actually still available to the user until it is overwritten? Are files in the citadel directory deleted, too?

For some background: we are trying to limit the size of our Citadel database. We are logging a lot of data,
and the hard-drive gets filled up pretty quick. We are wondering if the lifespan settings are reliable enough to limit the disk space. Any ideas?