DCC question

[Rigby]

How does DCC work: does the controller send a message to the decoder, which then remembers the last command, or, does the controller keep sending its message and the decoder reads the frames addressed to it?

Put practically: what happens if you have a train running on loop at constant speed until it encounters a section of track isolated from the rest of the track unless momentarily energized with the same signal that the train had been receiving before entering the dead track? Will the train start rolling again? Or will it wait for a new "go" command?

I would like two track run through staging reducing to single track mainline on the visible portion of the layout. It would be cool to be able to put a short section of isolated track on each of the staging exit tracks so that a train will hold up before entering the single track visible mainline until it receives authorization to proceed.

 

[UP2CSX]

Any electrically powered locomotive needs electricity and DCC doesn't change that need. As soon as the engine encounters a dead section of track, it will stop running. Assuming the dead section of track doesn't cause a short, the decoder will remember that it was last assigned to move at a certain speed and in a certain direction. Once power is applied, the engine will begin to move again. In theory, this should work if the train was moving at the speed and direction you wanted before it hit the dead track and then you energized the track to get the train started again. Of course, it''s just as easy to cut the power to the engine using DCC and then select the engine and start it moving again. No insulated sections to worry about and You can come out of staging at a slow enough rate to make sure things don't fly off the tracks.

 

[Rigby]

Thanks, Jim. I assumed that the train would resume whether it remembered the command or reheard it. The reason for this question is the desire to let a mainline train circle unattended but prevent it from fouling the local, so hands-on control wouldn't work.

 

[SpaceMouse]

To answer your question simply, once a engine starts it will continue at that speed until you change it. On my Zephyr, if i kill the power and come back a month later, the engine will start and run from it's last command. (You have to stop your engines before powering down.)

 

[Rigby]

Thanks, Chip.