A Panel is a set of icons representing various components of a layout. Some of the icons available in JMRI© include Turnouts, Sensors and Signals Masts. You can also include a background icon to represent your layout on your Panel.
The Panel Editor which you use to create a Panel is described on the Panel Editor Help page.
Clicking on a Turnout symbol flips it from Closed to Thrown and vice-versa. A Turnout also has "Unknown" and "Inconsistent" states, represented by an icon with a question mark and X respectively. These represent a state where no information has been received, and where the information is internally inconsistent (e.g. both Closed and Thrown at the same time).
This control can be used in various ways. For example, you could have a Turnout Icon covering a Turnout on a schematic diagram. When you click on it, the Turnout on the layout would be commanded to change, and the track diagram would show which way a Train would be routed. Or you could use icons that show a lever to the right or left, and create a Panel that looks like a traditional US&S Panel.
"Sensors" can be used to represent occupancy indicators or other inputs. The default icon is a small circle, with color used to represent the state of the Sensor. These respond to changes on the layout automatically. Clicking on a Sensor Icon causes the Sensor to alternate between "Active" and "Inactive" states. With the default icons, Active is a green circle and Inactive is an empty circle. These are meant to represent a lit/dark Panel indicator. A red circle represents the "Unknown" state, used when no information has yet been received from the layout.
Creating a PanelPanels are created with the Panel Editor, which allows you to place images to represent Turnouts, Sensors (on some systems) and trackwork.
If the "Panel items popup menu active" box is checked in the Panel Editor, a small popup menu will appear when you right click an icon. Most icons allow you to Rotate and Remove the icon. There are other options depending on the type of icon, for example, you can disable a Turnout Icon so it doesn't actually control anything.
If enabled via the checkboxes on the Panel Editor, you can move an icon by dragging it around the Panel. For more precise positioning, many icons can access the Coordinate Editor to move the icon by a specific number of pixels or set it to an absolute location.
When the checkboxes in the Panel Editor permit it, the popup menu may include items to recall the Icon Editor to change the icons or the entity it represents. Other items likely to be available are: rotations, scaling, font sizes, colors etc.
The popup menu may also change if the configuration of an item is changed. For example, if you add Feedback to a Turnout, the popup menu includes a new item choice called "Tristate". Tristate allows you to use the "Inconsistent" icon, which is one of the four possible icons available for a Turnout. Normally when you first click on a Turnout Icon it commands the layout to change the state of the physical turnout. If you use Feedback for a particular Turnout, the icon display will wait to hear from the layout before modifying the Turnout Icon to the Closed or Thrown icon. By using "Tristate", the icon will change immediately to the "Inconsistent" icon when the Turnout Icon is clicked. Inconsistent in this case means that I've commanded the Turnout to change and now we're waiting to hear if it actually happened. If and when the layout returns the actual or "known state" of the Turnout, the icon will change to that state. If you don't use "Tristate", when you click on the icon, it may take some time (milliseconds to seconds depending on the hardware system) before the Turnout Icon responds with the known state of the physical turnout.
The Panel pane menu includes an item called "Marker". You can use a Marker to represent a Locomotive or other device on your Panel. You can move the Marker around the Panel to show the Locomotive's current position. Markers are always moveable, and their popup menus are always active. To create a Marker, select "Add loco" or "Add loco from roster" from the "Marker" menu. The "Add loco from roster" option will use the Road Number from your Roster file as the label; if the Road Number wasn't entered when you created your Roster, PanelPro will display the DCC address of the Locomotive. To remove Markers from your Panel, use the "Remove markers" menu item.
The Marker's popup menu allows you to change the Marker's color, font size and style. The menu also allows you to remove the Marker from the Panel.
If you want to keep your Markers between operating sessions, you can save the Panel and the Markers will be saved to your Panel xml file.