Section 17 • Trend Chart Overview; Chart Operation - Emerson VILTER MicroVission Operation And Service Manual

Section 17 • Trend Chart
Overview
This screen allows the Operator to view and adjust set-
tings for the Trend Chart, see Figure 17-1.
The trending feature can be started & stopped from this
screen, and the Operator can select up to four variables
for on-screen plotting.
Each variable is assigned a specific color, and both the
plotted trace and the vertical axis labels for the variable
will be of the same color.
Other than the variables, the operator can select the
time intervals for plotting as often as necessary. The
vertical axis scale and offset for each variable plotted is
based on the range of values of the entire data plotted
on screen.
The available data for display is 120 hours maximum.
MicroVission Controller • Operation and Service Manual • Emerson • 35391MV 1.3

Chart Operation

Pen Selection
Pen selection allows the operator to select up to four dif-
ferent variables to plot on the screen (In red, blue, green
and yellow). The operator can select "None" as an option
to disable the plotting of data for a pen. The options in
the pen selection drop-down boxes will depend on the
channels selected in the Trend Setup screen.
Start/Stop
This button allows the operator to Start/Stop the trend
feature. When the trend feature is not running, the but-
ton will display "Start" and will be green in color. While
the trend feature runs, the button will display "Stop" and
will be red in color. By pressing the "Stop" button the
trend data is saved to a file.
Zoom In/Out
These buttons allow the Operator to adjust the number
of data points plotted on the screen. At the maximum
zoom level, 3 minutes of trend data occupy the whole
screen, and the Zoom In button will be inactive. At the
minimum zoom level, the full 120 hours of trend data
will be available on the screen and the Zoom Out button
will be inactive.
Figure 17-1. Trend Chart Screen
17 – 1