I am using Ignition 7.1.8 for a data logging application. Most of the data logs are time based (every 30 seconds or every 5 minutes, etc) and are working just fine. However, three of them are event based and for them I am using polled reads as set up by checking “OPC data mode: Read” on the advanced options window. Unfortunately, these three are storing data from the previous event each time they run. It is like the trigger causes the write of the stored values on the Ignition screen and then it goes ahead and updates the stored values. Whereas it should update the stored values first and then write the data to the database.
I can fix this problem by changing the data mode back to “subscribe” but I thought for an event triggered data log “read” would be better. In the meantime, I am a little leery of the “read” mode.