What is DCC?
Most literature on Digital Command Control start off like this. "Digital Command Control is a way to run a lot of trains on your tracks without a whole lot of complicated wiring, toggle switches, and power packs." All very true! You take some special throttles, plug it into a "command station/booster", run two wire to your tracks, load up the tracks with locomotives, plug in the power supply, and away you go.
Then they complicate things by comparing DCC with the good old-fashioned DC power pack!
Erase the Good-Old-Fashioned DC Power Pack From Your Mind
Forget everything you know about running your layout using the good-old-fashioned DC power pack. Most magazines, how-to books, websites, and other media compare DCC to DC. Forget it! Drop it! Erase your mind! Running your layout using a good-old-fashioned DC power pack no longer exists!
The Networked Computer Network
Now that you've erased you-know-what from your mind, let's take a look at how a bunch of computers, printers, scanners, servers, modems, and other devices are hooked together to form a computer network. If you work or study in an environment where computers, printers and other devices are connected together in a network, you're well on your way to understanding Digital Command Control.
The Basic Computer
We have a basic computer in front of us. We type on the keyboard to enter instructions. We move the mouse and right-click, left-click or middle-click to enter more instructions. We get a visual display of what we are doing on our monitor.
Not all computers have the same capabilities. Your computer might have a modem, a scanner, a joystick, a printer. My computer might have more memory, hard drive, more powerful software. My computer might even be called a "server" or a "mainframe" computer.
"Hooking Computers Together"
Let's connect your computer and my computer and our friends computer together in a "local area network" or LAN. This way, we can share resources. Instead of a whole bunch of small inkjet printers, everyone can use a faster laser printer hooked into our network. We can even add a colour printer to the network, a scanner, a fax machine, a modem, or many other different types of devices to our network.
This is the power of a networked computer system.
So, let's recap all of this.
We've probably over-simplified the situation - but you get the picture? If you don't here's a picture for you.
So What's DCC Got to do with Computers?
Lets apply some of this computer terminology to model railroading.
A picture is worth 1,000 words. Here's our DCC picture.
That's all DCC is - a networked computer system used to run trains!
The only difference between a computer network and a DCC network are the tracks and the power in the tracks. Because we need a bit of power to run the locos, the power in the track is typically a continuous 16 volts at 5 amps. The electricity is alternating current - but not the type you're familiar with. We won't go into the details at this point - perhaps later on.
Let's take a look at some "Laws of DCC"