I am working on a project where I want to get totals from tags each day. Then at 00:01 the totals get logged into another tag. Then this info could be dumped into a table for a month period. Does anyone have any easy ways to accomplish this?
Totalizing is often a challenge, especially if you cannot lose even a second or two’s worth of data. I recommend using non-resetting odometer-style totalizers in integer registers in your PLCs. Snapshot these values at any desired interval, and store the snapshots into “reference” tags any time you would otherwise zero the totalizers. Display the delta from reference to latest value as the operator’s view of the totalizers. (I do the deltas continuously in the PLC where integer rollover arithmetic is convenient, and they are then available for traditional HMIs, too.)
This approach allows you to compute a total for any time period for which you have a start and end recorded in your DB. If you need extreme precision, you can have the PLC also copy the odometers into snapshot registers exactly at the time intervals, along with a timestamp value, removing OPC driver latency.
Thanks for the info. I will try that.
Ok, how can I get that info to be displayed in Ignition? What I am looking for is flow totals. I have everything setup for 11:59 each evening to grab the current total. All of that is working great. I just want to put that info into a table each day so that I can look at what the flow totals are for a month or more.