Question:
I’m plotting a pen in E3Chart via AddPoint method; however, when using this, the AddPoint method extends its last point on the horizontal axis to a value higher than expected (42500) (see the figure below). Why does this happen? Can I plot the pen up to the last point without this extension?
Solution:
E3Chart’s AddPoint(ValueX, ValueY, [Quality]) method adds a final point to the real-time buffer. Buffer size is only valid after pen connection. If you create the pen in E3 Studio, connection is automatic; but if you create via scripts, you will need to use the Connect method afterward. This method is for real-time pens only, and therefore the UseTimeStamp property must be False. The Quality parameter is optional, and it indicates the quality of the point to be added. When not informed, the system assumes point quality to be good (192). The number of points to be added to the pen depend on buffer size (pen’s BufferSize property).
It may happen that when using this method, AddPoint extends the last point to a value higher than desired. To make sure the last point doesn’t extend on the horizontal axis when you’re using the pen’s AddPoint method, there are two possibilities:
- uncheck Use E3TimeStamp option (on the pens list); or
- unckeck Use TimeStamp option (on the pen’s properties Data tab).
If you’re creating the pen via scripts, you must configure UseTimeStamp property as False. That way, AddPoint method won’t extend the last point on the horizontal axis beyond the desired limit (see the figure below).
