# Help with reversing section



## tazzytazzy (Dec 27, 2007)

Hey everyone. In the final stages of track planning and getting down the wiring layout, haven't laid any track yet. Planning to this week on the right side of the layout. I don't have enough track to complete the layout yet, but have enough to fill just past block #2. The below blocks will have one, two, or three detection zones within a block, while the turnouts will not have detection. However, my question is regarding the reversing section. I have a PSX-AR for my reverser. 

I just want to confirm. I should be able to place my reversing section on within block 2 of my diagram? (I drew this up to show blocks for to automation).









Basically, block #2 is the very back of my backyard, and i really only have space to run one train that would look good, or two trains if one of them willl be on concrete. blocks #1, #2, #3 are all viewable from the backyard. For the rest of the train, you have to walk around. Even then, you can't really see the whole length of the track. Trains kind of disappear...which is how i want it.

I want to be able to "park" a train or two on some sidings and have various trains cross block #2 to make it appear random.

Thanks for your feedback.


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## High Ball John (Jan 26, 2009)

No, 

Follow one rail around either of your loops and you will find that one side of your track connects to the other. 

You will need two reversing sections one in each loop. 

What kind of automation will you be using? I'm into that too.


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## tazzytazzy (Dec 27, 2007)

Ok. That's what I was afraid of. 

Can I put it in a single block, like #7. Or, do i need to do the entire loop?


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## Greg Elmassian (Jan 3, 2008)

Whole loop is better considering train length. the entire loop on the 2 loops just east and west of #2. 

If you make reversing loops too short, then you have parts of the same train crossing the insulators in both "ends" at the same time... can be trouble, especially with locos... 

Greg


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## chuck n (Jan 2, 2008)

Reversing loops work very well indoors, You have a lot of wiring, relays and switches that Mother Nature loves to mess with. In my opinion you would be ahead of the game by adding a second parallel track in block "2". Get rid of the reversing loops and then you can easily handle everything else with toggle switches or some automated system. Reversing loops add much more complication than is needed. Chuck edit, remember if you are running lighted passenger cars. The entire train must pass the gap before you change the polarity. Otherwise if it stops with a lighted car ( passenger or caboose) straddling the gap, you will get a short.


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## tazzytazzy (Dec 27, 2007)

@High Ball John: Sorry, I didn't answer your question. I'm going to try JMRI first and if that doesn't work as I want, probably end up with RR&CO. Looking at the features, I'll probably end up with RR&CO, but they are very expensive and I'm looking for other solutions first. What about you? 

@Greg: Thanks for you input. I figured that's how i should do it, but looking for alternative solutions. 

@Chuck: My problem is that I have 12 inches of space between my patio pavers and a 5 foot retaining wall. A few inches are taken by plants that I want to have the train go around/between. If I put two tracks down, one track will be on the pavers and make the whole thing look a bit off - but will see what alternatives I can come up with. I was planning to float the track on the bark that is already there and will blend in with my garden. 

The goal of my layout is to have a track through my garden, it's NOT for realistic operations or be prototypical at all. I just installed my first DCC Decoder last night into an eggliner that I got a few years back for dirt cheap - and I got it to work on a 10' test track.  Now, to reprogram the the sounds as it came with steam engine sound. LOL It's a Christmas eggliner - so santa saying "ho ho ho" for the horn may be fitting.


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## toddalin (Jan 4, 2008)

Posted By tazzytazzy on 16 Apr 2013 11:09 AM 



@Chuck: My problem is that I have 12 inches of space between my patio pavers and a 5 foot retaining wall. A few inches are taken by plants that I want to have the train go around/between. If I put two tracks down, one track will be on the pavers and make the whole thing look a bit off - but will see what alternatives I can come up with. I was planning to float the track on the bark that is already there and will blend in with my garden. 

 




A "gauntlet" would be cool and get rid of the reverse loops without taking up much room.


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## Greg Elmassian (Jan 3, 2008)

Not to divert the thread, but since this is DCC, a reversing loop only needs a single pair of feeder wires to it (the loop is electrically isolated), so don't understand the "lot of wiring".. 

Furthermore, the best (in my experience) autoreverser for G scale DCC is the DCC specialties PSX-AR, and it has no relays or switches. In fact, put it in a weatherproof housing and connect the 2 input leads to the mainline rails, and the 2 outputs to the reversing loop, situate it at one of the "ends" of the loop and you might have 4 feet of wire total. 

The DCC autoreverser is the most simple piece of electronics you will find. It does what it says, automatically reversing a section of track as needed. 

Also the entire train needing to pass the gap before it hits the other gap is not always true. Today's autoreversers are much smarter than they used to be. 

Regards, Greg


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## tazzytazzy (Dec 27, 2007)

Greg, 
Perhaps I need a little help. Do I even need separate power districts? I was planning on having 2 power districts within each loop - each power district powering half the track, but both coming from the same 10AMP power supply. However, I plan to run both buses on each loop back "home" in case I ever need to add another 10 amp booster. I just simply move one of the buses to the new booster. Block #2 would be powered from either bus for now. 

How would I wire this? I'm planning on this: 

From booster A, there will be two bus wires leaving. Bus 1 will go through the PSX-AR and then will power districts 2, 3, 4, 6 (the outer #6, didn't realize I had two #6s). Bus 2 will go through a PSX-1 to power (inside) #6, 7, and 8. _BTW, block #7 is actually 35 feet..my diagram is wrong_. Then, if I need to add a booster, I just add one and move say bus 2 from booster A to booster B - and I'm done! 

But you are saying the entire loop should be on an auto-reverser. Would I go booster -> PSX-A -> then the two buses? Don't I need to divide this up into districts? If I add another booster, how would I wire that in? 

Also, i'm wiring for block detection. I'm planning for automation. I'm using a digitrax BLD 168 and I realize that the BDL is broken up into four detection sections per power district - was planning two use 2 BDL168 sections per power district). So, this would need to fit in the above. I'm using RD2 remote sensors and connecting those up to the BDL168 input sensors. This allows me only lay one bus wire for many detection blocks, with smaller wire to report occupancy. Do RD2's work in the garden as expected? I'm planning to us sprinkler wire as it's 18 gauge and has 5 wires in it. This would allow me to wire up 4 detection sections pretty nicely. 

-- 

Then, this fall, i plan to pretty much duplicate the wiring on the east loop to the west loop - and moving block #2 to the west side booster. Again, I'm planning to wire buses back "home" in case I need to increase the number of boosters. 

Thoughts? Pitfalls? Precautions? 

Any working experience of using RD2s in the garden? 

Thanks.


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## Greg Elmassian (Jan 3, 2008)

The autoreversers basically create separate power districts, you will have 3 power districts, 2 autoreversers. 

yes, booster to autoreverser and then to all separately powered districts WITHIN that loop. 

I think your detectors will work fine, as planned. 

Never used the RD2s, but you will most likely want them in weatherproof enclosures. 

Greg


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## toddalin (Jan 4, 2008)

TazzyTazzy,

Did you know that the various methods for dealing with reversing loops used with simple track power can also be used with DCC without the need for DCC modules?

It may involve a bit more wiring (and maybe head scratching) than using DCC modules, but it also may be much cheaper, if that is a concern. Many people into DCC don't realize that this option is still open to them.


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## Greg Elmassian (Jan 3, 2008)

The autoreversers are $45 each. This cannot be a cost issue with the already stated block detection hardware being added.

They are "intelligent" in that they can discriminate between a short, inrush current charging caps in a decoder, and a true need for autoreversing. 

They are also solid state. 

To wire the layout to work with DC is more involved and less reliable and will not work as well on DCC, but as Todd brings up, it is an option. 

But most people in DCC DO INDEED realize that they can still buy something with switches and relays and no intelligence to handle real shorts vs. the need to autoreverse.... "we" just choose to do it better (for DCC only).









I believe you can buy an autoreverser that needs additional isolated sections and has a relay from Massoth. This works on DC and DCC.

Greg


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## sharpn (Apr 30, 2012)

Greg

I have a fully DCC outdoor layout, based on LGB switch controllers and the short-circuit type LGB 55080 reversing loop modules. I use a Massoth 1200Z central station, with 2 1200B power boosters - so I have 3 separately powered, isolated, track domains.

The issue is the reversing loops. Some are simple out-and-back loops, while others are the result of Wye junctions. I have a total of 9 of these older 55080 modules controlling these 9 reversing loops and they seem to work OK.

However, I have not been running many trains simultaneously, so the issue of having trains in different reversing loops at the same time has not arisen - but it may in the future.

Various comments I have read suggest that I should only have one train in ANY of the 9 reversing loops at any one time. Is that correct? Or is it just that no more than one train can ENTER/LEAVE any of the loops at the same time. In other words, there could be trains in several of the loops, provided only one is crossing any of the loop boundaries at the same instant. The latter would clearly be far less restrictive operationally. 

What actually happens if 2 RLMs are activated simultaneously?

Also would it be the case that the loops in domains powered by different power supplies are not affected at all by what happens in the OTHER domains?

I ask all this because I am about to add a tenth reversing loop and I will be using the new LGB 55081 RLM and this offers the option of non-short circuit operation, presumably using track sensors and extra wiring. [Only because the 55080 has been discontinued!] 

If the short circuit method of operation is not going to cause overly restrictive operational problems I could simply continue in this mode. Otherwise I could be faced with upgrading all the old RLMs to the newer version and wiring them for track sensor mode. Clearly, this would be a major exercise, with considerable expense involved. I don't want to do this unless it is really necessary.

So, am I likely to have problems running multiple trains, that may be in different reversing loops at the same time, with these short circuit RLMs, or is there only a problem if two trains cross any of the reversing loop boundaries at the same time? 

It is very difficult to get clear information on this issue, so any clear explanation would be appreciated.


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## Greg Elmassian (Jan 3, 2008)

I think the comments that you can only have one train in ANY of the 9 loops come from people who really do not understand DCC. 

It's really simple... you sort of have a "main line", and then a reversing loop... the reversing loop, not the main line, is reversed in polarity when going in or out of a reversing loop. 

Therefore it's really simple to understand that no reversing loop would affect any other one or any other train. 

Now if you have a train that is crossing 2 loop boundaries at the same time, you need to look into it a bit further. 

The newer reversing loop controllers also can handle a reversing loop within a reversing loop, and guard against both autoreversers reversing at the same time... the only autoreverser that does this that I know of is the DCC Specialties PSX-AR, which probably is the reason it is the most popular unit in the US. 

Without a track plan I can only give these observations, but there is STILL a lot of misinformation about DCC and autoreversers, and much of it is self-serving from the manufacturers.... I run what works best, and not surprisingly it's what most clubs use too in large layouts. 

Greg


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## High Ball John (Jan 26, 2009)

If the short circuits that may occur when entering or leaving a reversing section get propagated everywhere then you can only have one train enter or leave any of your reversing loops at the same time.

There are ways of restricting the propagation of the short circuits to say power districts, in which case the only restriction is that only one train can enter a leave a loop in the same power district at the same time.

It is difficult to say without knowing more about your system if your whole system is affected by a short circuit or only part of it. You could work it out easily by experimentation.

When a train causes a reversing loop short circuit the other reversing loop modules detect the same short and reverse. This is why when two trains are traversing a different reversing loop boundary at the same time everything stops.

The reversers with detection sections remove this restriction, because there is no short circuit and so the other reversers don't also reverse. Of course you still can't have trains entering and leaving the same reversing section at the same time.

The type with and the type without detecting sections can be freely mixed.


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## mbendebba (Jan 22, 2011)

Posted By Greg Elmassian on 17 Apr 2013 01:22 PM 
The autoreversers are $45 each. This cannot be a cost issue with the already stated block detection hardware being added.


I believe you can buy an autoreverser that needs additional isolated sections and has a relay from Massoth. This works on DC and DCC.


Greg 



You seem to be having a tough time understanding what the Massoth reversing loop is and what it is not. 

let me repeat what has already been said the last time this subject was discussed. Simply stated: t*he Massoth reversing loop module does not need additional isolated sections*. It can effectively manage a reversing loop the old fashion way, like the PSX-AR, using short circuit detection. But, it can also manage a reversing loop more intelligently by preventing the occurrence of a short-circuit, no arcing or wheel pitting. It can even manage a reversing loop using both methods concurrently. 

Mohammed

AllAboutLGB.com
MassothUSA.com


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## Greg Elmassian (Jan 3, 2008)

John: do you run DCC? Basically all autoreversers also function as circuit breakers, the better ones work well.... the poorer quality ones might go nuts if presented with unusual situations, like a loop within a loop. So the very short duration "short circuit" will not affect any other part of the layout. That was the question and the responses are muddying the waters. 

Mohammed: I do not have a tough time understanding at all... I'm PAINFULLY aware of the features of the Massoth module... why do you INSIST on pimping Massoth at every quarter with the new excuse that I don't understand... did you bother to see how OLD what you quoted was? TWO MONTHS AGO, get OFF my case with your Massoth stuff. We beat it to death a long time ago. 

As an aside, why has everyone lost the ability to see the date on a post? It must be a virus. 

Sharpn, as I predicted, this has turned stupid. 

Please continue with me on private email. I'll no longer contribute on this thread.... 

Greg


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## High Ball John (Jan 26, 2009)

Sorry Greg but I disagree with you. I think we will have to agree to disagree. I have no wish to upset you.

It is most certainly true that in short circuit mode other reverse loop modules will detect a short and will switch at the same time as a loco enters a different reverse loop. if this were not true then there would be no problem with two trains entering different reversing loops at the same time, because each would be independent of each other.


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## mbendebba (Jan 22, 2011)

Posted By Greg Elmassian on 16 Jun 2013 03:33 PM 
John: do you run DCC? Basically all autoreversers also function as circuit breakers, the better ones work well.... the poorer quality ones might go nuts if presented with unusual situations, like a loop within a loop. So the very short duration "short circuit" will not affect any other part of the layout. That was the question and the responses are muddying the waters. 

Mohammed: I do not have a tough time understanding at all... I'm PAINFULLY aware of the features of the Massoth module... why do you INSIST on pimping Massoth at every quarter with the new excuse that I don't understand... did you bother to see how OLD what you quoted was? TWO MONTHS AGO, get OFF my case with your Massoth stuff. We beat it to death a long time ago. 

Greg 

Greg: Your statement is incorrect regardless of when it was posted; a correction was required particularly since the thread is still active. Mohammed


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## Greg Elmassian (Jan 3, 2008)

I'll explain. Say you have a mainline section and it is powered. Now you have 2 separate reversing loops one at each end of the mainline. Train enters reversing loop "A"... the autoreverser that is connected to THAT reversing loop detects a short BETWEEN one or both of the reversing loop rails and the main line, and in microseconds it switches polarity OF THE REVERSING LOOP A. The autoreverser on loop "B" detects NO short circuit between loop B and the main line.... this is because it is ONLY monitoring between the mainline and loop B rails, NOT anything to do with loop A or a dead short on the main for that matter. So autoreverser B does not operate. You are incorrectly assuming how an autoreverser works, clearly you are assuming a short between the 2 rails on the main line triggers the autoreverser... it does not. The autoreversers are monitoring shorts between the main line and ONLY the rails in the loop they are protecting. If all autoreversers "toggled" every time there was a short on the main line, none of this would work, and the thousands of DCC layouts around the world would not work either. Greg Posted By High Ball John on 16 Jun 2013 03:58 PM 
Sorry Greg but I disagree with you. I think we will have to agree to disagree. I have no wish to upset you.

It is most certainly true that in short circuit mode other reverse loop modules will detect a short and will switch at the same time as a loco enters a different reverse loop. if this were not true then there would be no problem with two trains entering different reversing loops at the same time, because each would be independent of each other.


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