It's very possible if you don't wire your DCC programming track properly, that you can accidentally burn out the circuits in your command station.
To avoid accidentally burning out the circuits in your command station when programming a loco, it's best to have a DEAD TRACK SECTION between your programming track and the rest of your layout.
The following diagrams illustrate how to wire a programming track in this fashion using a 4PDT toggle switch:
(Click image to enlarge)
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:
(Click image to enlarge)
If you don't do this, 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!
