Overview
This is a number of articles that explain (or attempt to explain) how I intend or have achieved a system of Computer Interaction - the way of plugging the PC into the railway layout, and getting it to do some of the hard work. This is a project built up in modules, such that each area can be utilised fully on it's own, but becomes of extreme use when the Master Plan is finally achieved.
At all times, I have strived to build in fail-safes, so that if I should initially fail, it won't bring the trains to a complete halt - it will just require isolation of the latest gadget to get going again. This is all experimental stuff and I am testing out each design as I write up each section, so bear with me as I amble along to a final conclusion !!
Stage 1 - Preparing the Permenant Way
The very first of these articles deals with the very basis of wiring itself. This is a major decision area from the very beginning, as the future design modules depend on getting this correct now.
The first school of thought is track sectioning or cab control. You can either follow the methods of Logic-One by Trevor Lloyd-Lee for a good control system (Trevor's method is similar to mine, only better explained!), or you can look at the layout wiring system I have devised called Point-to-Point - a logical wiring concept which details how each section can be connected together automatically, and can do away with all of those section switches that make most layouts look like the average Jumbo Jet cockpit panel.
School of Thought no. 2 is Command Control systems, such as DCC - the advantage here is easier wiring and control of any loco irrespective of position, but the controller side is a little more complex with the need to fit a decoder chip in each loco. I would suggest a good read-up in the Model Railway Control Concepts Exchange before deciding which way to go.
Stage 2 - Getting it all under control
Once the layout is tracked and wired, a control panel can be made that will permit your dream to begin it's life.An example of over-the-top control can be found in my PowerPanel section - this is the basis of a touch control that does away with the irritation of non-working push-buttons on controllers and the concept is moved on in PowerRoute - the linking of PowerPanel to route selection with collision-condition fail-safes.( This in english means that the panel will display a warning if you try to route a train into an already occupied section, but you need Track Detection to do this!)
The next rampage down the Auto-road is Track Detection, allowing us to see our trains on the layout - and subsequently turning our signals red behind the train. My favourite method is sectional detection using electronic discriminator circuits that detect current flow but positional detectors work just fine for signal control, and later this can be linked into an electronic system that clears each section after the train has passed - mine is designated PowerLock, and operates a sectional lock system that eliminates two trains meeting each other (I did say this was theoretical, didn't I ? ).
Stage 3 - Plugging in the PC
The final chapter arrives like your average APT-P (late due to tilt-failure !! - sorry). We've got the trains going where we want them, the signals are protecting the rear of the train, and for those lucky (or is that psychologically unsound) individuals with PowerLock, at least one section apart - what could possibly follow that lot. Well explore the area Plugging In and couple the nearest PC up and let's play serious trains. I'm not talking of full all-out control (but those interested in the concept - we'll talk after class!), but auto-signalling controlled by a bit of computer programming that intelligently reads the layout (all those track detectors ?), and offers the next train due in sequence in the same way that your fellow operators do from the fiddle-yard whilst reading that confusing card with hiero-glyphics that refer more to nucleur physics than the make-up of the un-fitted freight next out.
My version is likely to be written in QBasic, using a prototype card (a use at last for those unwanted XT-compatible portables - remember that the BR class 91 is controlled by the same chip - yes, it is an 8086/8088 in there !!!!!). As expected, mine will be called PowerBox - now didn't that surprise you - and a rough-up of expected interfacing with the layout is included so that the layout will still work without the PC plugged in !
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January 1999