Trend a dataset equation that finds the ratio coal tons per MW for each month. I need to do it per month because the coal conveyors don't run all the time.
I am using VB to create my datasets. The audience likes processbooks so that is where the trending needs to happen. I don't have access to the PI servers performance calculations, but I can use datasets to make it happen.
My dataset results trend great unless it is a time related calculation... then I run into trouble. Here is what I am trying to do:
Find Heat Rate using the IO method using a value that is already totalized, and a flow rate that I need to totalize.
The coal conveyors externally totalize tons of coal fed, so the number just increments higher and higher.
The Megawatt signal is a flow rate. To I need to totalize that. I plan on figuring this ratio per month. The end result will be btu/kwh but for this help, just tons/MW will do and I know how to scale it.
I think that one problem has to do with the time range of the trend doesn't match up with what the dataset equation time span. It would be great if the trend could still be widened and still work.
My thinking was to take a snapshot of the coal tons at the beginning of each month and divide that by the totalized MW signal. Here is what I came up with that does not work:
MyDataset.Expression = "TagVal('Coal Tons','bom-1m') / TagTot('MW','bonm-1m' , '*')"
Thanks for reading.