Coffee Table #3 Design


Note: The links on the left side of this page and the other Model CT-3 pages will take you to detailed information about the new coffee table's design and construction.

“Train-Brain” software from CTI Electronics is used to control all aspects of the layout in Coffee Table #3. The software is configured on a Duo Processor T8300 2.4GHz Toshiba touch screen Tablet PC running Windows 7. The Tablet communicates with the CTI hardware via CTI's USB Bridge.

User Interface

The CTI software allows the user to build dynamic interactive virtual control panels that display all of the layout functions including such things as train and trolley location, speed and direction, status of scenery lights and operating scenery, turnout direction, etc. On-screen controls give the user complete command of the layout at all times..

Program Design Objectives

There are two primary objectives for the layout's controlling program:

  • The first objective is to provide the ability to run the layout either manually or automatically. For the CT-3 layout, that involves implementing a manual mode of operation that allows the operator to control the train(s), and a fully automated mode of operation that requires no operator action.

  • The second objective was to prevent accidental (or deliberate) train derailments. In particular, it must not be possible—in either mode of operation—to change the setting of a turnout while the train is passing over it, and it must not be possible to run the train over a turnout that is thrown the wrong way. It also must not be possible to rear-end train equipment that has accidentally uncoupled from the engine.

Current Program Overview

To date, the only train program that has been implemented is a "track cleaning" program that automatically routs the train over the entire layout in a relatively efficently manner. The algorithm is simple: when the train approaches a turnout where a choice can be made (i.e., main or branch), change the setting of the turnout to whatever it wasn't. In other words, whatever the train did last time, do the opposite this time.

In addition to the train program, the trolly has been programmed to run continuously from end to end. The train and trolley are aware of each other, and the program includes code that prevents collisions at the crossover that is shared by the train and trolley.

As for accidental derailments on turnouts that are thrown the wrong way, the code to prevent that is running at all times.

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