Jim,
I assume you are aware how to set turnouts electrically? With a switch and "switch machine", which moves the turnout lever for you, to turn the turnout.
With DCC, there are "stationary" decoders. These are special decoders that are for operating equipment. With DCC, each decoder is assigned a number. (be that decoder in a loco or not). You select the "number" on your controller, then operate that decoder, be it in a loco, or "stationary". Speed the loco up, or slow it down, turn the headlight on/off etc.
A "stationary" decoder has, usually, 4 functions, each with an on/off type of functionality, or apply power for a specified amount of time. What you use each function for, is up to you. the decoder will have a wire attached to it for each function.
So you can select stationary decoder No 5, and function 1, and hook the decoder wire output up to the turnout motor. **click** and the turnout switches, or you may have it wired to the boom gates and flashing lights of your level crossing.
Then you can select decoder No 6 (which may be your loco) and move the loco off to where you want it. If you then select decoder No 7, which may be another loco, the previous loco will continue on running, at the previously set speed, while you operate the other loco. Then select decoder No 8 (which may be your lineside camp) and turn the fire "on". Go back to the turnouts decoder, and switch another turnout..... and so on.
DCC has constant full power applied to the track, and it's the decoder in each loco that varies the current, or turns power on/off to the wires leading from the decoder to the motor, or lights or whatever.
DCC does this by sending computer commands along the track that the decoder picks up. The commands are in computer language, but look something like this.
'decoder No 1' - 'set direction forward' - 'set speed 50%' and the loco with decoder No 1 in it will move off at 50% of full speed in a forward direction. You will have selected decoder No 1, then pressed the "forward" direction button on the controller, and turned the knob to half way. The controller generates the computer commands for you.
So, for instance, your lineside camp may be decoder No 4.
The command would be: 'decoder No 4' - 'turn function 1 on' - 'set light mode to firebox' and this will turn the fire at your lineside camp on. On your controller, you would select decoder 4, then push 1 on the number keypad. push 1 again to turn it off.
Get the idea? :thumb:
You can even take this all a step further, and plug the whole thing into your computer, and have a computer program, with a screen just like the driver controls of a loco on your screen, and move the controls with your mouse to drive your locos etc. There are computer programs around that do this.