Primer on control systems?

Check out my post at the bottom of the first page of this thread. It's the one with photos

 Then come back to the remarks I added below--you'll need to have read my post linked above to get the gist of the rest of it.

DCC is a command-control protocol created by the National Model Railroad Association (NMRA). A fair number of companies produce electronics (decoders) and controllers that operate trains (typically in HO and N scales, as well as "G" and 2-rail 'O') under this standardized control protocol, in a manner much like TMCC/Legacy and DCS. Unlike the 3-rail systems, the DCC protocol is open--no manufacturer "owns" the specification, so anyone can produce controllers and decoders that operate under DCC.

3-rail O-gauge came up with their own systems since at the time, the 3-rail manufacturers (Lionel, at first) couldn't make DCC operate reliably in the 3-rail environment, which is extremely rough, electrically speaking what with all the high-amperage demands and electically noisy AC motors that were still commonplace at the time. I'm not certain what MTH's precise motivation for making their own system was, other than insulating themselves from any constraints that might emerge from their biggest competitor, and/or to one-up the competition, and/or bypass percieved deficiencies in DCC

Since then, DCC has been revised and updated to address many of the earlier issues, and MTH added DCC capability to their newest control boards, known as Protosound 3. A switchover to DCC is unlikely in the 3-rail 'O' world, as the two biggest players in it have too much invested in their respective systems to walk away from them. In 2-rail O as well as the smaller scales), DCC remains dominant.

---PCJ

Thanks for the link - very informative and makes me rethink my plan of attack...probably just startmout with a simple 1 train loop that the grandkids can enjoy and slowly upgrade to remote control.

Question, can new engines be run using the power supply I have (without the need for either the TMCC or DCS)?

Shoot me an email and I have some good info I will send you.

Gilly

Email sent....added email to my profile (I hope)

Yes. New engines with TMCC/Legacy or DCS continue to support the "conventional" control method.  Note that conventional control is a "control system" in its own even though even here on OGR the Control System sub-forum only lists the 3 you mention.  Thousands of layouts continue to use conventional.  If you buy a new engine from one of the smaller manufacturers, it will likely only have conventional control capability.  For a single-loop, single-engine layout, going forward, stopping, reversing, changing speed, and perhaps blowing the whistle and ringing the bell can provide hours of enjoyment.  You can get remote-control capability for conventional control.

So in one sense, your existing transformer is the only controller that can universally control all engines albeit with "limited features" (to your point).

In my opinion, the only universal control will be one that talks directly to the engines using a wireless standard (Wi-Fi, Bluetooth, whatever).  The 3 existing control systems you mention place the control signal on the track requiring track-side black-boxes proprietary to model trains which means low-volume and relatively expensive.  As to whether market forces would ever permit this is a separate issue.

It took me a while to wrap my head around all this so I feel your pain! The key thing to keep in mind is that with conventional trains the train speed is controlled by increasing/decreasing the voltage being sent to the track. Apply more volts = trains goes faster. Cut the juice = train stops. With the digital control systems (DCC, DCS, TMCC, Legacy) the voltage stays at a constant, set amount (usually 18v) and the speed is dictated by a circuit board inside the engine. Now if you have both older style conventional engines and new digital ones you won't be able to run them at the same time on the same track because the digital engines need the constant voltage. To run both you'd need to break the layout into separately powered blocks or loops so one loop could have a steady 18v for digital control while the other has variable voltage controlled by the transformer for conventional trains. The different loops can be connected, you just need to create a break in the circuit (a block) where they meet. I have two connected loops powered by two transformers along with a mix of conventional and DCS locomotives and I run everything from transformers. It's fine though I have to be careful when routing trains from one loop to another. 

Simplest answer is yes. In the 3-rail'O' world, command-control locomotives all decide how to behave depending on what they see on the track at power-up. No command signal detected? Conventional operation ensues.

---PCJ

There is a way to control Conventional Engines with DCS.

Each DCS TIU (The command Base) comes with 2 fixed channels and 2 Variable channels.

The Variable channels change the voltage to the rails just like your Transformer does, so Conventional engines run just fine on it.

If you wire up the Variable channels, they can also run Command engines, just switch them to Fixed mode on the remote and address the engine.

There is also a way to run a modern engine and a conventional engine on the track together. The Conventional engine must be pulling a heavy enough train that it is slower than the Modern one at max commanded speed.

Then you slow the modern engine down with the command system and maintain spacing with it.

Problem points exist in this method.

IF the track is not level the conventional engine will change speed as it runs up and down grades and you will have to compensate with the commend train to maintain spacing.

Now, a bit more info on the Command systems:

TMCC and LEgacy send the commands to the engine via radio waves. The track is only used as a ground for the signal.

DCS sends the Commands and receives the reply from the engine via the track, not radio.

DCS is the only system that gets data back from the train, it can tell you many things about the engine and the operating conditions.

NONE of the other systems have any data back from the train, they do not even know if the train received the commands.

Thanks all...I think I grasp the concepts....I've got enough info to start looking and talking at the lhs....

Now the decision will be which control system - then that sets the course for the engines and final retirement of the original engine.