Chart view

A Chart view plots report parameters over time. Numeric parameters draw as lines, dots, fills, or bars. Integer parameters draw as colored state bands or change lines. String parameters draw as change lines. Authors add it with Add chart under Setup → Reports; viewers open it on the report page.

Settings

Each row shows the editor label, the recipe field for API and CLI authors, the allowed values, and the default for a new chart.

Setting	Field	Values	Default
Height	height	Main plot height in pixels, 40–4000. The navigation strip adds 56 px below it.	280
Show tooltips	showTooltips	On or off	On
Chart display	chartDisplay	Fixed (frozen), Movable (movable)	Movable
Navigation strip	navStrip	None (none), Fixed (frozen), Movable (movable)	Movable
Legend	legend	None (none), Non-interactive (non-interactive), Interactive (interactive)	Interactive
Show comments	showComments	On or off. Paints comment stripes above the plot.	Off
Minimum precision (ms)	minimumPrecisionMs	Whole milliseconds, at least 100. The finest time slot the chart requests when zoomed in.	1000
Max points on screen per parameter	maximumPointsOnScreenPerParameter	100–2000	1000
Points per parameter in the navigation strip	fullRangePointsForNavigationPerParameter	100–2000	1000
Use the selected series for Y-axis labels	focusAxisOnSeries	On or off	On
Show min/max per parameter	showMinMaxPerParameter	On or off	Off
Realtime update	realtimeUpdate	On or off	Off

The last six settings are under Chart options.

Series

Under Series, Add series from parameters lists the report parameters that are not already on this chart; each parameter can appear once. A series keeps the type of its report parameter. Series are stored in parameters, in order from back to front: later series paint over earlier ones and stack on top of them. Move up and Move down reorder them.

Setting	Field	Applies to	Values	Default
Opacity	opacity	All	0–1	1
Show as	showAs	Numeric	Dots (dots), Line (line), Fill (fill), Bars (bars), Stacked fills (stacked-fills), Stacked bars (stacked-bars)	Line
Show as	showAs	Integer	Filled areas (filled-areas), Vertical line on change (vertical-line-on-change)	Filled areas
Show as	showAs	String	Vertical line on change (vertical-line-on-change) only	Vertical line on change
Decimal places	decimalPlaces	Numeric	0–12	2
Scale multiplier	scaleMultiplier	Numeric	Any number	1
Scale shift	scaleShift	Numeric	Any number	0
Gap threshold (ms)	smallestGapSizeMs	Numeric	Whole milliseconds, 0 or more	120000

Removing a report parameter that a chart uses asks for confirmation and removes its series from every chart.

On the report page

Detail

The chart first shows a low-detail overview of the whole data range, then loads finer detail for the visible window, so zooming out shows data immediately.

Each point is the latest reading in its time slot. A brief change inside one slot can stay hidden until you zoom in far enough. Slots are never narrower than Minimum precision (ms).

Moving through time

With Chart display set to Movable, dragging the plot pans the time window and the mouse wheel zooms around the cursor. The window can extend past the first or last reading. With Fixed, the plot does not pan or zoom.

The navigation strip is a low-detail overview of the whole data range below the main plot. It appears when Navigation strip is not None and the data range is known. A shaded overlay marks the current window. With Movable, select a span on the strip to change the window. The strip does not show live points.

When the report has Lock time range on, panning, zooming, and strip selection are off: Movable acts as Fixed. The strip is still shown.

Tooltips, legend, and Y axis

With Show tooltips on, hovering shows the time (YYYY-MM-DD HH:mm:ss) and each series value in its own units, without scale multiplier or shift. Integer values show the text label recorded with the reading, such as Open, when there is one; otherwise the number. The tooltip also lists integer and string changes.

The legend sits below the main plot, above the navigation strip. With Interactive, clicking a parameter hides or shows it in every view of the report.

With Use the selected series for Y-axis labels on, clicking a series recolors the Y axis and labels it in that series’ own values. Clicking an empty area clears the selection. The chart has one Y axis.

Values, scale, and gaps

Scale multiplier and Scale shift change only the drawing: the plotted value is value × multiplier + shift. Tooltips and CSV export keep the original values.

For numeric series, a time slot without readings that is longer than Gap threshold (ms) breaks the line. 0 breaks the line at every missing slot. Integer and string series hold their last value across gaps.

Min/max

With Show min/max per parameter on, each numeric series shows the minimum and maximum of the visible window in the legend (min and max) and as dots on the plot. They update when the window changes and include live points in the window. Integer and string series have no min/max.

Realtime update

With Realtime update on, the chart receives parameter values as they arrive while it is open. It only listens: it never asks devices for a reading. Values arrive while something else, such as an open live view or a background read, is reading the parameters. When nothing reads them, no new points appear; that is not an error.

The chart keeps up to 1000 live points per parameter. Charts with Realtime update off never show live points, also in shared snapshots. When the window ends at the current time, live readings move the end of the report window forward; see Following the current time.

Live values are limited to 100 distinct parameters across all charts with Realtime update on in the report, counting each chart’s hidden parameters too. Above that, those charts show a limit error instead of live values. If live updates fail, the chart shows an error and keeps the data already drawn.

Colors

Each series uses its parameter’s Default color and the series Opacity. Numeric zone colors paint as bands behind the series; they fade to half strength when more than one numeric series is visible and none is selected. Integer Filled areas paint full-height bands in the value colors behind everything. Vertical line on change draws a thin line in the value color at each change. Integer and string series do not change the Y range. Bars and fills start at zero, and stacked bars sit on the previous bar.

Comments

With Show comments on, comments that overlap the window appear as colored stripes above the main plot (not above the navigation strip). See comment markers.

Time labels and errors

X-axis labels use YYYY-MM-DD when ticks are a day or more apart, otherwise YYYY-MM-DD HH:mm:ss, in the report timezone. Errors, including requests over a size limit, are shown inside the view; data is never silently cut off.

Related

• Report settings
• Report page
• Table, time bars, histogram, calendar, hourly matrix, state duration, Sankey
• Comments
• Readings API: readings.segments, readings.minMax, readings.timeExtent (readings procedures), and readings.realtime