Rockwell Automation FactoryTalk View Machine Edition Users Guide - Manual (Page 544)

F ACTORY T ALK V IEW M ACHINE E DITION U SER ’ S G UIDE
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Chart
The chart is the area of the trend in which values are plotted. It is bounded by the y-axis on
the left and the x-axis on the bottom. It contains the plotted trend data (shown using pen
lines and pen markers), as well as grid lines (if you choose to display them).
Y-axis
The y-axis is the left vertical edge of the chart. It is also known as the vertical axis.
Vertical axis labels
The vertical axis labels show the scale (range) of values for the pens. If desired, you can
set up the trend to omit the vertical axis labels.
The minimum and maximum values for the scale can be determined automatically (using
the best fit for the current data), be derived from a pen’s minimum and maximum values,
use a constant value, or be controlled by tags.
You can set up the trend so all pens use the same scale, or use individual ranges for each
pen. If you choose the latter method, create a next pen button in the graphic display, to
allow operators to view the range for each pen. When the operator presses the button, the
vertical axis changes to the new pen’s range.
For example, if Pen 1 has a minimum value of 10 and a maximum value of 100, the range
on the vertical axis is 10 to 100 when the pen is selected. If Pen 2 has a minimum of -10
and a maximum of 50, the range on the vertical axis changes to -10 to 50 when the
operator presses the next pen button.
X-axis
The x-axis is the bottom horizontal edge of the chart. It is also known as the horizontal
axis.
Horizontal axis labels
For standard charts, the horizontal axis labels indicate the time span covered by the trend.
For XY Plot charts, the horizontal axis labels show the scale (range) of values for the pen
selected to serve as the x-axis pen.
If desired, you can set up the trend to omit the horizontal axis labels. The number of labels
depends on the size of the trend object and the number of vertical grid lines.
Pens
Pens are the lines and symbols used to represent values. The values can be tags you are
monitoring, expressions that manipulate tag values, or constants.