TMCC AND train detection

You may want to post this in the TMCC section.

The was one guy who posted about using a computer and some custom made layout control boards to do just what you are asking. It was a pretty complicated setup.

You may be able to use traditional style relay block controls where the relay still allows a small voltage (5 volts maybe?) to the track to keep the circuitry alive but not have enough power to move the motors.

I think this would be pretty "hit or miss", depending on the locomotive in question.  I've tried reducing the track voltage, and at around 7-8 volts some TMCC locomotives drop out.  At that point, they're still rolling along, especially with a light load.

The way to do this is using a link to the TMCC/Legacy command base and some sort of intelligent box to at least sense the location and send a command.

I picture locking E unit in forward, making blocks with insulated rail and relays directing juice one track or another.  A basically conventional operation.

I use RFID technology which is similar to EZ Pass. A transponder tag which is the size of a nickel coin is placed on an engine. When the engine passes near a reader module the control board that the module is connected to sends TMCC commands into the DB9 port of the Command Base and thence out to the engine. I have several options for commands. One is to blow the grade crossing sequence if the reader module is placed near a grade crossing. Another is to stop the engine if the module is used in conjunction with a signal. If the signal aspect is red and the signal sends a ground input to the control board then the engine will get throttle commands to come to a stop. Each engine can have its own unique tag.

This has limited use and a more sophisticated system would be to connect the reader modules to a PC.

Possibly you could use a Lionel ARC, and trigger start and stop sequences when a particular track sensor is occupied or cleared.

The problem is knowing which train is to receive the command.  I don't think there's any way of doing that with the ARC.

I have implemented a full microcontroller automated train running system for TMCC and DCS, but it requires RFID tags in locomotives or rolling stock to tell the system which train is in which block.

I came across several of the RFID circuit boards that I used to sell years ago. If anybody is interested contact me.

A different tack might be to install a relay or equivalent in the engine to cut power to just the motor leaving full track power to the electronics.  Whatever detects the higher priority train would activate some signal on the lower priority track section that activates the motor cutoff relay.  Certainly not as impressive as the RFID/computer control techniques but ought to be relatively inexpensive - maybe $10?

I have not done this myself but would be curious if someone else has tried this.  I have some additional thoughts on this if this approach adds to the discussion.

To do the relay trick, you'd have to modify each locomotive that might need to be stopped.  However, it is an interesting approach and would probably work.  Perhaps a reed switch with an electromagnet under the track to trigger it.

Thanks for all of the responses. I also came across a website cti-electronics.com seems more aimed for dcc. It has some rfid products and computer train control claims can work with any gauge.