Charts - Emerson 475 User Manual

Charts

Charts display a graphic view of variables as they occur over time. There are four
major types of charts:
• Strip/sweep/scope - Displays variable data with an x-axis of time.
A strip chart continually updates the chart, scrolling from right to left.
A scope/sweep chart paints the window from left to right, and then paints the
window from left to right again, overwriting the oldest data. A vertical line is used to
separate the old an new data. When the data reaches the right edge of the screen,
the data is then plotted from the left edge of the screen and the x-axis is updated.
• Horizontal bar - Displays data represented as bars from left to right.
• Vertical bar - Displays data represented as bars from bottom to top.
• Gauge - Displays a gauge chart, similar to an analog car speedometer.
NOTE
If a chart is displayed for an extended time period, the 475 Field Communicator will
have decreased response time due to the large number of data points in the chart.
Strip/Sweep/Scope Charts
The strip/sweep/scope chart formats device data into a line chart that displays device
data over time. The labels and axis displayed are determined by the device
manufacturer. Use the drop-down list to select the variable you want to highlight. The
selected variable is displayed as a bold, solid colored line. Other variables that share
the same source or same Y-axis appear as thin colored lines on the chart. Variables
that do not share the same axis as the selected variable appear as dashed, colored
lines. The colors displayed are determined by the device description and may vary
between devices.
A vertical line may be displayed in the chart to distinguish between the old and new
data. The vertical line advances as new data is displayed.
For the sweep and scope charts, the pan, zoom-in, zoom-out, and reset affect only the
Y-axis.
The time shown on the x-axis starts at the time the chart starts. The chart update rate
is determined by the device manufacturer. The default chart update rate is 1 second.
Figure C-3. Strip/Sweep/Scope Chart Example
C-3