Historic List Data Recording Frequency

[Emre123124]

Hello,

There are a few issues that I need to fix regarding the Historic List in the Geo Scada Expert 2023 November 2024 version.

The first of these is related to the recording of live data I receive from the field. I receive data from the field via Modbus TCP and it is updated instantly in Geo Scada. This data is recorded in the historic list every 5 minutes, which is what I want. However, in these 5-minute recordings, the data is recorded twice in a row within the same second. In other words, there are 2 data records when there should be 1 data record in 5 minutes. What can I do to record this number of records as 1 in 5 minutes? The sections where I set the recording and change frequency with the Historic List that I viewed for the signal are as shown in the image below.

Another issue is that I produce percentage data from this live data that I mentioned using the Calculation signal. This signal should be updated instantly according to the field signal I mentioned above and recorded in the Historic List every 5 minutes. However, when I try different things, this signal is either not updated instantly in some of them, or the recording frequency occurs at every change, or even if it records as frequently as I want, the number of data is 2 or 3.

With the settings below, the data is updated at every change, but the Historic List recording frequency is the same.

When I change the execution settings to Periodic, the recording frequency changes to 1 data per minute (I did this for the test, it would normally be 5 minutes), but the data update frequency is also 1 per minute, it is not updated instantly.

Actually, I want the update and recording frequencies to be the same for both signals. They should be updated instantly according to the value coming from the field and the Historic List should be recorded as 1 data every 5 minutes. Can you help me with this?

[JChamberlain1]

That's how GS implements historic compression, it saves the values before and after a significant change.

https://tprojects.schneider-electric.com/GeoSCADAHelp/Geo%20SCADA%202022/Default.htm#CorePointConfig...

Your minimum interval of 300s = 5min is driving it. If you want one value, use a historic view.

[Emre123124]

I couldn't understand exactly how using the Historic View would benefit me. When we add from the Historic View, aren't we actually doing something like creating a query? What exactly will I use this for? And do I need to do something like edit the query to integrate it into my signal? Can you explain a little more about how I should proceed with the Historic View list or share documentation on this subject?

[sbeadle]

Jesse is correct - the historian is there to record meaningful change, not fixed time data. Compression is there to reduce the number of samples stored based on its rules.

Use a Historic View to read out, list and report on historic data in fixed periods. A Historic View can be configured with time period, averaging algorithm, data filter and the default query period (overridden by a WHERE clause on the timestamp).

When you have set up your view, define the SQL and attach it to buttons in your mimics. (Or create an 'Extra Table Query').

[sbeadle · Accepted solution]

Yes, a Historic View is a query on the raw data. You can use it in on-screen lists, mimics, reports, SQL Export files.

Perhaps your expectation is that the raw data must contain only one value at fixed time intervals, with no others. This is not practical if your device goes offline.

The Historic View is a way to derive a single value per time interval from the source. You also get a quality number from which you can work out if the value was interpolated from missing data.

If you really really must have a single value stored in the historian, then turn off historic compression and configure the point to scan at your choice of interval.

Note your calculation point will execute on Tag Processed. (But if you have more than one input to the calculation point, it will update on each tag processed. If C = A + B, then you'll get updates for both A and B changing).

[Emre123124]

I understood the Tag Processed part as changing according to the update frequency of the signal I used in the calculation made in the Calculation Point. The live data used in the calculation there changes in Scada every time there is a change and the Historic List recording frequency is 2 in 5 minutes. When I select Tag Processed in my Calculation signal, it changes instantly in the same way as the live data, it records 2 data in 5 minutes in the Historic List. If I select the Periodic option instead of Tag Processed in the Calculation signal, I can record 1 data in 5 minutes, but my Calculation signal does not change instantly, it changes every 5 minutes. As you said, if I set the Compression option to No Data, it records every change in the Historic List. In this way, it can even record 2 or 3 data per second.

Do I need to look for a solution in the live data section coming from the field? The settings of the Historic Compression section of that signal are as follows.

Also, is this actually the same as the queries we use in the Historic List regarding the Historic View section? But how can I write it in a format suitable for it? do you have any documentation about this?

[geoffpatton]

If you cannot get anything else to work for you, you could try using an ST program with one input that will trigger the ST execution, and the output being an execute on the calculation point. you'll have to set the calculation execution to Method.