Hi All, I know that this has probably been asked a million times, but I can’t find the answer. I am hoping someone can give me some advice and help. I am running 3 O Gauge Locos on a single loop all in the same direction. They are DCC and I am trying to stop one train from catching up to the other, without having to manually adjust it all the time, so something automatic would be great. The DCC system I am using is LocomotiveDCC (https://www.locomotivedcc.co.uk/system/). I was told Block detectors would do this, but having just spoken to DCC Concepts, in the UK, they have said that this wouldn’t work, So now I am extremely confused. Is there something like a plug and play option? Or is there a company that just makes a unit that would do this? So any advice would be much appreciated, please be gentle as I am only relatively new to DCC Hope someone can help, Thanks Simon
I don’t know the specifics for this, but I have seen a similar project on the MERG website for block detection. Now whether it can stop a train (such as a signal at red as the section ahead is occupied) must be out there as I’ve seen folk use them. Maybe this is the one… (I think you need to have some settings on the decoders too for a coast if power interrupted or goes to a DC current. ) sorry, not much help. I’ve not seen the question asked before….
Just checked and the MERG one appears to Be for a display only of track occupancy https://www.merg.org.uk/resources/dcc Andy
Hi Simon You do not say how long the loop is but I suspect that block detection will only tell you whether a loco is within a block, a section of track or not. I also suspect and partly guessing here that you would need to link a block detection system up to a train controlling application which would for example stop two trains being in the same block at one time, that application would require feedback from the locos so it knows the DCC address of each loco and which is catching up with another to slow it down, the DCC system you are using is IMO unlikely to be capable of that. The loop would have to be segregated into train length blocks and in 0 gauge that could be quite a length. I think you need to provide us with more detail so that a member with that experience can assist you. Jim
Thanks Andy, Any help is much appreciated, hopefully somebody else might have had this problem and come up with a solution, Cheers Simon
Hi Jim Thanks for the reply. I am running 50ft of track in the loop, I think what I am trying to accomplish is to be able to leave the trains running, they are in a sitting room, so I am really looking into leaving them automated and not having to put to much input in to them, but leave them running, almost fully automated I suppose. I thought the Block detectors was going to be the answer, but to tell you the truth I am not too sure what the answer is now. I have reached out to the DCC manufacturer of the controller and he just pointed me to DCC Concepts in the UK, but they have given me 2 different answers to the same question. 1 of their tech guys said yes it would work and another of their tech guys said no it wouldn't work, just really looking for some sort of inspiration. Cheers Simon
Hi Sam As Jim has said length and number of blocks will make a big difference. for three trains I'd suggest 6 blocks minimum, preferably 9 to give an empty space to move into. If you were using DC then a simple block signaling system would work, as it would cut the power to the occupied section until the block in front is clear. DCC however needs to tell the loco decoder to stop, JMRI Panel pro may well be able to do this, but how to do it is beyond me. If you are a member of MERG, then they produce a selection of block detection devices using various technolgies. These would provide an input to your DCC++ Arduino controller - this may give issues if you haven't free inputs. There is also DCC - ABC which may be what you are after - never used it so can't give any real life advice, however I did find this on tinternet DCC ABC (Asymmetrical Braking Control) is a feature in digital command control (DCC) model railway systems that allows for automated stopping or slowing of a locomotive on a specific track section. It works by modifying the DCC signal with a module that creates an asymmetrical waveform, which is detected by a compatible ABC-enabled decoder. The decoder then slows or stops the locomotive, enabling simple automation for tasks like stopping at stations without manual controller input. How it works Asymmetrical signal: An ABC module is placed in series with the track feed to an isolated section of track. It uses a simple diode circuit to create an asymmetrical voltage in the DCC signal. Decoder detection: A DCC decoder with ABC capability senses this asymmetrical signal. Unlike standard DCC, which has a symmetrical square wave, the ABC signal has a different voltage on the "up" and "down" pulses. Automated response: The decoder is programmed to respond to this asymmetry by slowing down or stopping, depending on the configuration. This effect can be adjusted with the decoder's settings (CVs). Installation: An ABC module is installed on the feeder wire for an isolated section of track. The track section must be isolated from the rest of the layout using insulated joiners. The section needs to be long enough for the locomotive to come to a complete stop safely. Key features and uses Simple automation: It allows for basic automation on a layout, such as a train automatically stopping at a station or in a fiddle yard. Bypassable: Many ABC modules include a bypass switch. When the switch is closed, the module is removed from the circuit, and the track operates as normal, which is useful for maintenance or when manual control is desired. Directional control: The direction of the asymmetry determines which direction of travel triggers the braking. This allows for control in one or both directions, depending on the module and decoder setup. Wide compatibility: Many modern DCC decoders support ABC, including brands like Lenz, Zimo, ESU, and D&H. However, some manufacturers, like DCCConcepts, have their own variations that may require specific decoders and modules. What you need ABC-enabled decoder: A locomotive must be fitted with a decoder that has the ABC functionality built-in. ABC module: An ABC module is required to modify the track signal for the specific section where you want the braking to occur. Isolated track section: The section of track where ABC braking is used must be electrically isolated from the rest of the layout. DCC Concepts sell ABC slow or stop modules Link is to thier page with additional info. But may require compatable decoders. Hope that help, or I may be right up the wrong reel Paul
Hi Paul, phew, fascinating but on my railway I am the train driver and not my PC, mind you, I've got more than enough of my own computerised tech associated with my railway to bury me as it is Jim
Hi Paul, Thanks very much for that, it has given me a lot to think about and on a Friday night . Liking the idea about this ABC Module, I am going to go back to DCC Concepts and see if they can give me some more information on Monday. It does sound like that could be the way to go. I didn't realise that it would be this complicated Thanks again for all the info, now I know what I am doing for the weekend Cheers Simon
To be fair, you only need one to stall with a bit of dirty and you still have a 3 train pile up and the rest.. At least with a block detection it would help to stop the said trains behind if one stopped in section, pretty much like the real thing. What would be great to see Simon do after hes solved the block detection is to link it to automatically operating colour semaphores !
Hi Chatty, as Andy points out, plus, the longer the run time the greater is the chance a rear end hit is likely, feedback to a train controlling gadget/application is essential. So the KISS principle may result in a rather hard rear end kiss or one pushing the other. Jim
OK Paul, I have spoken to NASA who referred me to SpaceX who passed me down to the Pentagon who think that they may have a solution with some software from their patriot missile system, which they think could possibly run 2 model trains on the same track. Although their technical boffins think that this is an overreach on their computing power.
Andy, Just on with the Big Bang Theory of the Universe, at the moment, once I’ve solved that I will get straight onto those semaphores
