I am using UDT and have memory tag of data type float, and I did the below setting for history to be stored in Mysql database.
However when I change the value from 0 to 1 and from 1 to 2 and from 2 to 3 and from 3 to 5, only 1 gets stored in the database.

When I set deadband to 0 and change value all the change in value gets stored in the database, I dont understand whats going on after I put some deadband.
Ignition uses compression on the historian to reduce data storage requirements. The two main settings that affect this are Deadband Style
and Historical Deadband
. This is explained in the manual.
https://docs.inductiveautomation.com/display/DOC81/Configuring+Tag+History#ConfiguringTagHistory-DeadbandandAnalogCompression
Note particularly,
Auto
The setting will automatically pick either Analog or Discrete, based on the data type of the tag.
- If the data type of the tag is set to a float or double, then Auto will use the Analog Style.
- If the data type of the tag is any other type, then the Discrete style will be used.
You might find Discreet
more easy to work with.
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I was having the thoughts that deadband is working like
abs(current value - previous value) >= deadband ---> store
Read the manual carefully. It took me several readings before I grasped how it worked (and even now I'm not sure). I think they have improved the explanation in the 8.1 manual in the link I gave you.
It's much more complex than that for "analog".
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