I am a new user of PI so would appreciate if someone can help me find a way to import only the data when the plant is running steady state to excel using pi datalink??
Thanks for posting on PI Square and welcome to the PI Community.
Datalink is an as needed query tool built as an Excel Addin. So, I would like to ask some clarification questions first
1) Are you looking for a way to pull data automatically when the plant is running at steady state?
Or the more likely case:
2) Are you looking for a way to pull data for a given time range taking into account the state of the plant. For example, if the plant was reaches steady state at noon and I'm pulling data from Midnight to Midnight. You would only pull data from the Afternoon to Evening (Noon to Midnight).
If its the former, that's going to be tricky. The latter is much easier. There probably is a tag or a set of tags that help indicate that the plant is steady state. For every datalink query, you can create filters to block retrieval of certain events.
Here I'm query for the compressed data of CDT158 from yesterday at midnight to today at midnight but only if the value of Sinusoid at each timestamp of events is greater than 50.
Please let me know if this would work for you.
Thank you Jesse for your reply.
i tried the second option of filtering and seemed to work fine to me. i got one more question i have noticed that when i call values as compressed data, different tags have different time stamps e.g if i call values for two reactant flow rates, reactant A has only 100 value and the other has 200 even if the time range is similar. so can i calculate or call up the missing values in between.
will have more question as i further try to learn more about PI.
That's an excellent followup question. The compressed data function pulls the actual events in a time range directly from the PI Server. Therefore, it is highly likely that different tags will have different timestamps. It all comes down to update rates, compression settings, and what kind tags we are dealing with.
That being said, if you are looking to get data at the same timestamps, you can use the Sampled Data Function instead. This function will collect data in regular intervals over a given time range. If there's an event at that exact timestamp, it will use that value. Otherwise, Datalink will interpolate using the archived events.
In summary, having different number of values and timestamps for 2 tags is rather expected. If you wish to analyze with the same timestamps, Sampled Data would be a better option for you.
i am unable to cell refer a value from pi server to use in calculation in excel.
I did a quick test and was able to have a cell reference for the PI Server. What are you seeing on your end? Screenshots would be really helpful to help me figure out what is going on.
Cell c484 & d484 are calculated using pi datalink calculate functions
Thanks for the image. I can't seem to replicate the issue that your having. Can you double check the formula for C484?
Also, we can double check the values seen by excel. Can you have 2 cells with the formuals: =C484 and =D484?
the value in C 484 is a pi advanced calculated value. for cells with =c484 and d484 i get a value = 0. seems excel is not reading the value calculated by pi.
Thanks. I agree the issue appears to be on the Excel side not the PI side. If you copy and paste the value (not formula) of cell C484 do you get the value or do you get 0?
Secondly, what version of Datalink and Excel are you using? I'm particularly interested in the excel version.
DATALINK IS 5.2 2015 & EXCEL 2010 14.0
I have not been able to replicate the issue even with your versioning. What were the results of copying and pasting the values of the cells? Do they equate to zero as well?
All in all, I would recommend getting a remote session by calling in to Tech Support. You can contact us at: Contact Us
Retrieving data ...