This is okay, but there is a better way ...

Mike:

The one real danger with what you suggest is the possibility of bridging the programming track rails with the rest of the layout. If that ever happens you could blow out your command station.

Since reading back CVs on the programming track can cause a decoder to "chirp" the motor briefly (the command station sees the brief current surge as a "yes" when the right CV value is found while reading), a loco can crawl down the programming track ever-so-slowly while on the programming track. If you're not carefully watching, the loco could bridge the gap between the programming track and the rest of the layout and ZAP! There goes your command station as the magic smoke gets released.

And once the magic smoke is gone in electronic circuits - they don't work any more - and there's no easy way to put the magic smoke back again - they only work when the magic smoke is there [wink].

There are lots of advantages to having the programming track on the layout, so the best way to wire your programming track is to use a 4PDT switch and to have dead isolation sections on each end of the programming track.

Once you throw the toggle from program to run, you can see the two isolated sections are reconnected to the regular layout track feeds and the programming track now works as a normal part of the layout:

As I mentioned, if you don't do this, then if you ever accidentally have a loco bridge the gaps between your programming track and the rest of your layout, it could burn out the circuitry in your command station - NOT GOOD!

Of course another option is for your programming track to not be part of the layout, but then you have to handle your locomotives to take them off the layout to the programming track and them put them back - increasing the chance you may accidentally damage your locos.

By having the programming track connected the layout and wired safely as shown, you won't risk damage to your DCC command station or your locomotives!

By the way, here's a 4PDT toggle switch, for about $6. It will let you wire your programming track as shown above.

toggle switch

Joe, thanks for the info.  That is a safer way, as I did not think of the movement of the engine while programing. 

Thanks again

Mike

A matter of how careful you are!

I made the pt at the end of a siding. I always face the loco towards the end of that pt. If it creeps while programming, it will always end up at the end of the track. (My bumper is two push pins with a rubber band across the track.) The only thing I can think of to help would be a light bulb to indicate when the track is one way or the other. Light up when switch is for programming? The way I use it is very straight forward. Switch the track for main, run the engine "forward" on to it. Switch it to pt. Do the programming. Throw the switch back and run the engine backwards off the siding. I've done this for over a year with 6 BLI locos and have never been even close to "running them off the pt onto the main". The only way I can think of having the extra wiring and the way described above is when you "might" have someone else operating on your layout - and want to program a loco. Otherwise, that siding is used as a normal one. And when I look at the toggle, it always is off or on main. If I see it towards the pt, I know there must be a loco on that siding. And since programming is not used very often, it don't seem to be so important to me. Just MHO and how I use it.

Separate programming track

I used to have one on my layout, now I've moved to a separate programming track. I have to handle locomotives anyway, so a couple more times to and from the programming track is not a big deal.

center off

I uses a DPDT with center OFF to power my programming track

The switch

I should have said my switch is DPDT. It is mounted upside down behind the fascia, sticking out like a sore thumb. You can tell instantly just by looking what it is. Center off. 95% of the time. I only throw it for the main when actually running a loco on it. I only throw it for pt when the loco is on it and that's all I'm going to do. Program it. When done, that switch is never thrown for the pt. So, it's barely 5% of the time it's powered for the layout. That's when you actually run a loco on it. And you don't even have to run a loco on it just to push a car on the siding. Lot's of time, that siding is dead when i push a car on it. And as I mentioned, the loco is always facing the dead end of the pt, so that any creeping is done away from the gaps or main/layout. Finally, that pt is 42" long. Plenty long enough for almost any loco you can imagine. IMHO plenty of safety factor. Also, I'm the sole operator, so there isn't anyone else going to be doing something stupid. OK? 

Throw to the left for main, to the right for pt. Simple. Why? Because the main is to the left and the pt is to the right - physically on the layout above. One don't need a college education to figure that out.

Moving locos to/from prog track

Dear MRHers,

FWIW, if you want a "no-touch" solution to moving locos to/from the Programming Track at the Workbench, you could do worse than the PECO Loco Lift...

https://peco-uk.com/products/loco-lift-and-storage-unit

Drop over/on-top-of the rails on any straight piece of track, run the Loco onto the LL, then lift away and carry to the Prog Track.

Happy Modelling,

Aim to Improve,

Prof Klyzlr

PS it may be arguably an "edge case", but for those with smaller layouts, who are tempted to "just quickly do a small loco programming tweak", be careful! I recently used my PwrCab to "quick tweak" a CV in a Lok-Select Loco, and inadvertently "broke" an Accessory 2x Servo decoder which was also wired to the Track Buss in the process!

I had made sure to remove all other _locos_ from the layout, so was sure "Dropping into Prog Track mode" would be "safe", but I completely forgot that there were still other _Decoders_ connected!  :-(

Upshot, it just reinforced to me that a Completely Isolated and Physically Seperare Prog Track is the "Fail Safe" option, both electrically, And mentally. The act of having to lift/move the Loco to a specific "Prog Track" gets your head into a "We are Programming Now, not doing anything else" mindset, focussed on the task at hand...