Circuit Builder

since 2.12

The Circuit Builder is a view of a Control Panel Editor panel used to create track circuits that are implemented in JMRI by OBlocks, Portals and OPaths. The prototype name for track having a device that can detect occupancy is Track Circuit. In JMRI we have misused the term "Block" and "OBlock" to refer to what in the prototype world is a track circuit. The term Block in the prototype world is a length of track defined by limits, whose use is governed by block signals, cab signals or block limit markers and train orders. That is, a prototype block incorporates a signaling system providing a way to manage safe usage of its trackage. So to model a prototype block, several track circuits may be needed. The term JMRI track circuit is just an attempt to get a little closer to prototype usage. For now, the Circuit Builder tool is concerned with the creation of track circuits, that is, OBlocks and their elements.

Circuit Builder is an alternative to using the Occupancy Block Tables. OBlocks, Portals and OPaths are created and linked by "point and click" on the icons of your layout diagram or panel. The three element types (OBlock, Portal, OPath) are created and edited using three editing modes of the tool. The result of this editing transforms the track in your layout panels to indicator trackage that displays the states of the blocks and paths by color without altering the original look of the panel.

Panel files previously made with Panel Editor can be used with Circuit Builder as long as they can be loaded into this version of JMRI. Circuit Builder will upgrade the track icons to Indicator Track icons. See The Item Palette for more information about Indicator track icons.

Mouse Operations

When in one of the editing modes of Circuit Builder, the mouse click conventions differ somewhat from those of the panel editors. When one the menu items is selected an editing window is opened and the panel is in Circuit Builder editing mode. Note the following when in Circuit Builder editing mode:

The Menus

The File Menu

The only menu item, Change View to Control Panel Editor, returns the Circuit Builder view to the Control Panel Editor view.

Menus in Common With Control Panel Editor

The Edit, Options, Zoom and Add Item menus are identical to those in Control Panel Editor. When in an editing mode (i.e. in any of menu items under the Add/Edit Circuits menu) these menus are disabled.

The Circuit Builder Menu

Creates and Edit OBlocks, Portals and OPaths and their display icons. The menu has the following menu items:

The Error Check Menu Item

Verify OBlocks, Portals and OPaths are complete and without errors. The menu has the following menu items:

How to Make OBlocks, Portals and OPaths

Creation and editing of these objects is done is with three editing modes of Circuit Builder.

OBlocks - Circuit Editing mode

Creating OBlocks

Editing OBlocks

Circuit Editing Mode

The Edit Circuit window is identical to the Add Detector Circuit window. Its purpose is to identify all the track icons that are used to display the track circuit. It also configures the OBlock sensors for occupancy detection and error indication. Oblock names can be changed and the track circuit deleted. Finally, the circuit track icons can be upgraded to Indicator Track icons.

Circuit Editing mode Dialog Box

You may leave Dark blocks (no occupancy detection) with track icons unconverted. There is a trade-off here on the appearance.


Portal Editing mode

The purpose of this window is to create and edit portals. A portal is represented by a red circle icon. The blocks it connects are determined by positioning the portal icon so it spans the two blocks it connects. That is, circle the gap between the two blocks with the red circle. In this mode, only portal icons can be repositioned. No other panel items can be moved or selected.

Portal icons are needed to graphically define Paths (See the next section). They serve no other purpose. After you have defined all the track circuits and the Portals and Paths needed to calulate routes; and have created and run warrants; and have tested everything sufficiently, these icons can be removed. On the other hand, there is no harm in letting them persist. They are only visible in the Circuit Builder view.


Path Editing mode

The purpose of this window is to create and edit the paths in the track circuit. In this mode, no panel items can be moved or selected.

Further Reference