Hi,
I created memory tags to store delta pressure data from a machine. I enabled the history, but it's not recording on change all the time. The tag is reset to 0 in the beginning of each shift by script. After that, the machine writes the value only once to the tag.
This is what I have in the database:
It works if I change the tag to save it periodic, but I don't want the system to save same value many times.
Any thoughts?
Thanks,
Are you sure it isn't working? You have deadband style "auto", which means "analog" for floating point tags. Analog deadband style uses linear forecasting to determine when to actually record a point (deadband deviates by set amount from local extrapolation). It delays recording by one sample to accomplish this, and throws away intermediate samples that fall on the extrapolated line.
If you do not want this documented behavior, set your deadband style to "discrete".
Thank you @pturmel !
Once I changed it to discrete, tag historian started saving the data as I wanted.
