Hi,
we have a temperature probe that in normal conditions measures temperatures in teh range of 15 – 30°C.
Due to a bad connection the temp sensor is showing readings of 850°.
The issue is repaired now, but consulting trend data now results in ‘unreadable’ graphs as the system scales to show the peaks.
In the era of mysql it was possible to remove those incorrect data entries from the trend database.
Is this possible on a cassandra system as well??
Hi Hans,
if the bad connection to the sensor leads to it showing the value: 850 consistently, it might be a ideal to add it as parameter exception value in the connector. that way it won’t mess up the average and max values if this occurs again
Regards,
Hi,
A good suggestion, but instead of checking if the value is equal to 850, I will check the specs of the temperature probe to determine the max temperature that the probe can measure.
With that information I will update the connector to set the value to ‘N/A’ whenever the temperature to be displayed is higher that the maximum temperature that the probe can measure.
- Open the Trend Graph: First, ensure you have the trend graph open with the parameter you want to analyze.
- Right-Click the Graph: Right-click on the trend graph area to open the context menu.
- Select Y-Axis Settings: In the context menu, look for an option like “Y-axis settings”
- Set Custom Range: Enter the desired minimum and maximum values for the Y-axis. This can help you get a different perspective on the data, especially if the default range is too broad or too narrow for your analysis needs (DataMiner Docs) (DataMiner Docs).
Hi Hans,
It’s probably possible on Cassandra to remove this, but as that is not my domain of expertise, I cannot advise on that (there are trend window calculations done min/max/avg, don’t know how tampering with the data will influence that or how trend points relate to each other).
Anyhow, about the ‘unreadable’ graphs: it is possible in Cube to right-click on the Y axis and select ‘Y-axis settings…’. Instead of setting it to “Auto”, a “Range” can also be specified where the maximum is set to e.g. 50 and the minimum to 0. This way the 850 peak will not be displayed.
Hope this helps a bit to have more readable graphs again.
Regards,
Agree on the trick to clean up the display – but still that keeps the excessive spikes in the db for avg/min/max calculation.
I guess recreating the element will be the easiest way out (at the expense of losing the history).
I’m not sure why you have to recreate the element. In any case when you zoom or pan past the point where the unexpected value happened, the auto scaling will adjust and you’ll have a nice graph again.
Scaling is there, however the Average and Max values are messed up.
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