Increase the data limit on a trend.

[vince2e]

Hello all,

I have a trend that is displaying a few DPEs, which have archive configs to History DB. Until recently, the trend worked great! I was able to display several months of data within a few seconds, but now I've been getting an error message saying

"The Timerange contains too much data. Curves cannot be displayed completely. Please choose a shorter timerange."

This occurs even when the timerange is less than 24 hours.

Is there any way to increase the data limit? Or has something else broke? Could it be an archive compression issue?

thanks.

[leoknipp]

From the description I assume that a dialog is opened which shows the information.
Please have a look at the PVSS_II.log file to see if an error is reported. Most of the time when a query limit is reached a log message is written.
If a log message is written when trying to open the trend please have a look at FAQ --> Log-Messages if you can find an explanation for it.

Best Regards
Leopold Knipp
Senior Support Specialist

[RudiKreiner]

It could be that your dpGetPeriod() call is being rejected because maxRequestLineCount (default value 100000) is being exceeded.
If that is the case you can set this parameter to a higher value in your config file (see WinCC help for details) but be aware that transferring bigger amounts of data will take more time)

After we upgraded from WinCC V3.9 to 3.14 we also noticed this problem. For example we have a datapoint that changes exactly once per second so if we open a trend for exactly one day then the default value of 100000 should be enough because a day has only 86400 seconds.
But it looks to me like the query is done for a longer period than requested. The time scale shows us exactly one day but the trend window has a horizontal scroll bar that allows viewing older data to without an additional call to the database.

[leoknipp]

When opening a trend with predefined curves (fixed dp element or $-parameter) or when using "connectDireclty" to connect a do element to a curve a dpGetPeriod() is made for the displayed timerange. At this dpGetPeriod() the bonus parameter with value 1 is used to get 1 value outside of the selected timerange.

In the described example the limit is exceeded because the value and status is read for the selected timerange, e.g. 86400 results for the value + 86400 results for the status > limit of 100000 lines.

In newer versions the default values for some data request / query limits have been changed to defined values instead of using no limitiation as default.
This is part of the "Error tolerance and stability" functions of WinCC OA, see WinCC OA documentation --> Installation --> Error tolerance and stability.

Best Regards
Leopold Knipp
Senior Support Specialist

[vince2e]

Thanks guys!

For those looking to increase the limit, add this to the config file:

[valarch]
queryMaxValues = 0


**Note: This will set the limit to no limit, which could cause errors and/or stability issues as stated in the Help Documentation. The default value for this is 100,000.

[vince2e]

My Data is displaying on the trend, but now I'm getting a SEVERE error in the Log


WCCOAvalarch (6), 2017.12.05 07:47:13.623, IMPL, SEVERE, 54, Unexpected state, General internal archive error (ErrNum=11), Compression level should be 0 but is 2 , archive set C:\\WinCC_OA_Proj\\HMI02\\db\\wincc_oa\\VA_0006/AR_0006_2000.01.01.08.00.00Archive set state set to offline., [D:\\workspaces\\3.15\\workspace\\Exe\\DataNew\\ValueArchive\\ArchivSet.cpp:1515]

Any idea on how to fix this?

[leoknipp]

Vincent Touhey wrote:

Thanks guys!

For those looking to increase the limit, add this to the config file:

[valarch]
queryMaxValues = 0

Before modifying any of the limits you should check if a log message is written when reading data fails.
For a historical query there are limits in the value archives and the data manager. Increasing only one limit will maybe not solve the problem.

Please be aware that using no limitiation for the queries is not the common use case.
You should use limits which fit the project requirements.

Best Regards
Leopold Knipp
Senior Support Specialist

[leoknipp]

Vincent Touhey wrote:

My Data is displaying on the trend, but now I'm getting a SEVERE error in the Log


WCCOAvalarch (6), 2017.12.05 07:47:13.623, IMPL, SEVERE, 54, Unexpected state, General internal archive error (ErrNum=11), Compression level should be 0 but is 2 , archive set C:\\WinCC_OA_Proj\\HMI02\\db\\wincc_oa\\VA_0006/AR_0006_2000.01.01.08.00.00Archive set state set to offline., [D:\\workspaces\\3.15\\workspace\\Exe\\DataNew\\ValueArchive\\ArchivSet.cpp:1515]

Any idea on how to fix this?

Can you please describe when the log message is written, e.g. during startup, when a fileswitch is made ....
I'm pretty sure that you do not get the log message when trying to read data.

When looking at the log message you will see the information for a archive file created in year 2000.
Are you storing data for more than 17 years in your project?
Which kind of data is saved in this archive (compressed data, values from the driver, ...)?

Best Regards
Leopold Knipp
Senior Support Specialist

[vince2e]

-The Error occurs whenever I open a trend object

-I am not sure why the archive file says year 2000, it was created in 2017. I have about 8 months of data stored. The values in the archive are from the S7+ driver, and then the archive is compressed (Level 1 & Level 2)


If the archive file is messed up is there an easy way to transfer the data with the correct time-stamp to a new archive file?

[leoknipp]

The file name only is not an indication that data is messed up in the archive. It is just the information when the file was created.

If you need detailed information please get in contact with your common WinCC OA support.
For further analysis some files/data for your project is needed and then it is easier not do it within the ETM Portal.

Best Regards
Leopold Knipp
Senior Support Specialist