Hi,
I am currently trying to plot a realtime tag and want to do it in a power chart due to the great additional functionality. However, it appears that it can only plot historical information via the power chart's built in tag browser. Is there any way to plot a realtime tag using the power chart, or attach the power chart to an external tagbrowsetree component?
No, the Power Chart can only display history. If you think about it, where would the trend data be stored?
You can plot in realtime but it's all based on the tag history.
Are you asking how to script a temporary data holder for the past 8 hours without using historization?
I think you could insert data to the historian, and remove it.
I don't think you will want to.
If you historize it:
Ad Hoc trends from Ignition exchange is what I am using at the moment in some cases.
PTurmel has a really nice viewer project as well.
There is a realtime mode on the power table.
I think you want the ad hoc trend though.
I also use a timeserieschart with historical setup like:
now(0) and aritehmetic (now(0), -8,'hour)
Maybe I don't know what a realtime tag is though.
A tag has to be historized, or have it's past recorded into something via transaction or script to pull up that data.
Create a new historical provider and store your tag to it. For this specific application, I would set it to 1 day partitons and prune after 3 days. Gives you plenty of fudge room if you need it.
Anecdotal, but the tables I used for efficiency trends, I prune after three months, even though it doesn't seem anyone looks at it past 2 weeks. 