How does the DCS signal actually work?

Click on DCS Patent as it'll explain it.

http://www.protosound2.com/

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Hi John - Take a look at this thread posted today. This is a sidebar question as related to how DCS works.

https://ogrforum.com/t...11#50704664809051511

I asked the following question about DCS Conventional vs Lionel Conventional, was unable to get an answer to my question.

This video is from my YT Channel, RS-1 running with MTH - DCS Remote.

https://www.youtube.com/watch?v=7y1V-15_mG8

I would also like to run my MTH locos the correct way in Conventional Mode. Page 113 of the MTH Operator's Manual / Fifth Edition. Gives the procedures, but this process calls for using the DCS Remote Control.

Lionel has a different definition for conventional operations. "Turn track power off. The powered locomotive will respond to the transformer's Throttle, direction, horn and bell buttons".

The Question: Will a MTH Locomotive respond to the transformer's, throttle, direction, horn and bell buttons? I have not tried this process, because I do not want to damage the electronics in a MTH / RailKing Locomotive.

If I'm understanding the patent correctly, then, it doesn't actually give any exact technical information and offers several ways the system Could work. The basic meat of it, however is that serial data is simply spewed out as fast as the electronics can send it riding on the 60Hz carrier, then clocked into the engine through a shift register.  About 121Kbps according to the information.  I can't find any information on what process is used to place the data on the carrier, or if it is say, a square or sine waveform.  All in all just as confused as I started.  

I'm not quite sure what the "chips" mentioned are.  Guess I don't understand how a bit can be split into a smaller amount of information.  My brain is telling me there isn't really a smaller unit than a single high or low, one or zero... a bit.  Maybe someone could explain these 'chips'? 

JGL

"In TMCC I know that the data is broadcast via radio just below the AM radio band, with the signal received through contact with the outside rail for one half of the radio wave and the antenna picking the other half from the ground plane."

Contact with the outside rail has nothing to do with receiving the TMCC signal.  It is a radio wave.  Lionel chose to use the outside rail as a handy antenna.  You could lay a wire near the track, connect the command base to that wire (and not to the track) and TMCC will work fine.

trainroomgary posted:

 

The Question: Will a MTH Locomotive respond to the transformer's, throttle, direction, horn and bell buttons? I have not tried this process, because I do not want to damage the electronics in a MTH / RailKing Locomotive.

Yes it will. I would of thought you knew that.

 

Bob posted:

"In TMCC I know that the data is broadcast via radio just below the AM radio band, with the signal received through contact with the outside rail for one half of the radio wave and the antenna picking the other half from the ground plane."

Contact with the outside rail has nothing to do with receiving the TMCC signal.  It is a radio wave.  Lionel chose to use the outside rail as a handy antenna.  You could lay a wire near the track, connect the command base to that wire (and not to the track) and TMCC will work fine.

Bob, you are correct that direct contact is not required, but it is the optimal configuration to my best understanding of the information on how the signal works in TMCC.  In effect when you have, say, a loop of track that is not connected to the TMCC base's U post, the locomotive's frame and through contact with the outer rail, that rail as well, become one half of a dipolar antenna, picking up the signal from other near-by track that IS connected to the base's U post.  The U post half of the signal will be much stronger with direct contact to a rail carrying the signal.  

This from Dale Manquen's fantastic explaination of exactly how the TMCC signal works: 

_{"The antenna connects through a wire to the input stage of the radio receiver. As we saw earlier, we also need a second half to the antenna system so that we can get current to flow through the receiver. For this application we use the frame of the locomotive as our ground reference. The received radio signal will flow between the antenna and the frame of the locomotive. Note that the frame is also connected to the wheels and hence the track outer rails. That means that our receiver is sensing the current flow between the antenna and the outer rails.}

_{We must stop here to dispel Myth Number 1 – “The antenna on a TMCC locomotive picks up the Track signal.” As we just concluded, one side of the receiver’s input connects directly to the outer rail, and hence the Track signal. If the antenna also picked up the same signal, there would be no voltage difference and no resulting current flow. The antenna IS NOT PICKING UP THE TRACK SIGNAL...."}  found Here: http://www.trainfacts.com/trainfacts/?p=317

Now, from what I've gathered on DCS, direct contact IS required for the DCS signal so it is an important distinction.

JGL