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Trend Refresh Rate

When creating a trend object at design time, set the trend Refresh Rate no faster than the time it takes to put a data point on a trend. Drawing extra data points only consumes additional memory.

The speed at which data points can be drawn depends on the time span specified for the X axis, and the width of the trend object.

To calculate the fastest possible refresh rate, divide the number of seconds specified for the X-axis by the width of the trend object in pixels:

(X – Axis (Seconds))/(Trend Object Width in Pixels)

Example

In the following trend object, the X-Axis Time Span = 10 Minutes = 600 seconds.

The Trend object's Width = 500 pixels.

Fastest Possible Refresh Rate = 600 seconds/500 pixels = 1.2 seconds/pixel

This trend object only shows a new pixel of width every 1.2 seconds. Therefore, setting the Refresh Rate higher than 1.2 seconds only consumes extra memory without showing more data.

Tip:

The X-axis cannot be changed dynamically at run time.

See also

Options on the General tab of the Trend Object Properties dialog box

Set up the horizontal axis for the trend

Set up common properties

Keywords: best practice, trend