A display is a container for widgets.

Most widgets are backed by a PV. Some widgets (e.g. widgets used for layout) are typically not connected to a PV. Other widgets (e.g. charts) can be backed by more than one PV.

Catalogue of Widgets

The default widgets in Yamcs Studio are listed below. Their runtime behaviour should be fairly straightforward. The various properties are detailed when we address the Display Builder.


Arc Rectangle Label
Polyline Rounded Rectangle Image
Polygon Ellipse


LED Progress Bar XY Graph¹
Image Boolean Indicator Gauge Intensity Graph
Text Update Thermometer Byte Monitor
Meter Tank

¹ Clear the view on this widget by right-clicking on it and selecting Clear Graph. If you want advanced controls, like zooming, activate the toolbar by right-clicking on your widget and selecting Show/Hide Graph Toolbar.


Action Button² Knob Image Boolean Button
Menu Button Scrollbar Check Box
Text Input Thumb Wheel Radio Box
Spinner Boolean Switch Choice Button
Scaled Slider Boolean Button Combo

² Action Buttons are often used to open other displays. Whether this opens in a new tab or in the same tab depends on how the display author constructed the display. Override the default by right-clicking the Action Button.


Table Grouping Container Sash Container
Web Browser Linking Container Grid Layout
Array Tabbed Container

Color Decorations

When a widget is backed by a PV, it will be decorated according to its runtime state. The specific colors of these decorations can vary since the default colors can be overridden (or disabled) by the display author.

State Decoration
Connected No decorations
Connected, but no value (yet) Dashed pink border around the widget
Disconnected Solid pink border around the widget and the label 'Disconnected' in the top left corner (space-permitting)
Expired Blinking solid pink border around the widget
Minor Alarm Solid orange border around the widget
Major Alarm Solid red border around the widget

Note that the color information for alarms is currently not as rich as it could be. Yamcs parameters support five different levels of alarms, as well as a range of special monitoring values. This information has for now been transformed using the following mapping:

Yamcs Server Yamcs Studio