Multiplying Values on an Easy Chart by a constant amount

Ignition
1

I have set up a historical display, based on the “Click to Graph” example.

I am displaying flow information, which is stored as meters cubed/hour (m3/hr) in the historical database. This works perfectly.

I would like to be able to switch between displaying the data as m3/hr and litres/second (l/s).

To convert from one to the other is a simple matter of multiplying or dividing by 3.6.

How can I achieve this automatically when the user makes a radio button selection on the Click to Graph screen?

Can it be done with calculation pens?
Is there any access to the data that is being used to plot the Easy Chart, so that I could simply multiply it by 3.6?

2

You won’t be able to perform that calculation using the easy chart. The calculated pens would be perfect if we had a multiple function. The only way to do this right now would be through scripting. In scripting you can query the data, loop through it, and perform a calculation. You would also have to use the classic chart not the easy chart.

In short, I will add a feature request in our system to get this functionality added. If you are still interested in the script let me know.

3

A multiply calculated pen function has been added to version 7.5.7.