PowerChart Step Data Pens

Hi forum!

Simple one! I cant seem to find the correct setting on a powerchart to 'Step' historical Data between stored datapoints. Changing the line settings to 'CurveStep, CurveStepBefore or CurveStepAfter' Seems to just make little steps between interpolations, not the actual as stored datapoints. I need the red line, not the current yellow one! :smiley:

I've checked the data and can see the database has the points I want. On a separate tag, I had to set history mode to discrete to get this to work... Not really a solution for this tag though.
Anyone got any ideas? (Really struggling even with the docs to understand whens best to use what history :sob: )

Thanks! :smiley:


Why not? Discrete is precisely what you seem to want. (You probably also want QueryMode=AsStored.)

Edit: Hmmm. PowerChart doesn't offer control over Query Mode. You may need to use a different chart component.

I thought (and im questioning it now!) that discrete mode was specifically for 1 or 0 tags, i.e. booleans? If I use this for an analouge, will it just act to store data every single time it changes? or can I still add some deadband to it?
The tag in question comes from a GC that updates its value every 10 minutes. As its repeated through a PLC, there could be some minor drift from time to time, so I didnt want it filling up the history with nonsense numbers.

This was exactly what I was looking for - And also found out it doesnt have it :confused:

Not just, but booleans are particularly appropriate uses of the mode. You can still have a deadband, but the fancy space-saving trend line-based storage decisions are skipped. (The analog mode delays the storage decision of a point until the next one comes in. See the docs for details.)

Smashing stuff - Thanks for clarifying! :slight_smile:

Just discovered something - If you set the 'Querymode' in the sqlth_te table to a 0, it renders the data without interpolation - Just not sure where I set this without updating the database! :slight_smile:

edit: So a datatype 1 (Analogue) with querymode 0 gives steps! :smiley: