I'm creating event frames and will do table lookups to collect some time series data which exist for the duration of the EF. One of the values I need to do the lookup is a guid, which is another table lookup - into an attribute in the primary referenced element. The lookup gets data from a table with all triggering events, and is configured with time context.
Since this is not a PI Point DR I am using a String Builder to collect the value (as described here), and this seems to work - except I have a big problem:
While the PI Point DR lets you choose between "End Time" and "Start Time" in the By Time Range option, I don't have this available for the String Builder DR, so I'm consequently stuck with the value at the end time for the EF. The EF's are created back-to-back, meaning the creation of the next one will stop the previous one. The result of this is that GUID I'm looking up is the value at the end time of the EF, and the end time of the EF is the same as the start time of the next EF. And suddenly I'm left with the GUID of the next EF in the previous one.
Are there any ways to collect table lookups with time context into EF's at Start Time, rather than the default End Time? If not, will OSIsoft implement this in the future?
(And no, there's no way to get this value into PI tags)