Which DCC Reverse Loop module?

[Peter749]

I want to fit a couple of Reverse Loop Modules to my layout and I would like to know what different makes people have used and what they think

The Gaugemaster DCC40 looks like it might suit

 

I'm using a Lenz DCC System with the LH90 controller on a OO Gauge layout

 

Thanks

 

Peter

[WIMorrison]

Depends on whether you intend to automate the layout at a later date. If you do then look at the LS 5410, otye use just ensure you choose an electronically switched module and not the old relay based versions.

[RFS]

The Lenz LK200 would be suitable as it's an electronically switched one, unlike the earlier LK100 which was relay based. 

[Peter749]

I won't be automating the layout.

 

The layout has a Helix which connects the top station level with the lower fiddle yards and I'm going to remove it

So the track on both levels will go round separate reverse loops.

 

Peter

 

 

[Peter749]

Just now, RFS said:

The Lenz LK200 would be suitable as it's an electronically switched one, unlike the earlier LK100 which was relay based. 

I looked at that one too.

It might be a good option as it keeps the Electrics all the same

 

Peter

[WIMorrison]

Makes absolutely no difference which manufacturer you choose - all they see is a DCC signal and haven’t a clue if it comes from Roco, Lenz, ESU or any other maker you can think of  

[ITG]

I’ve used the GM Reverse loop module for a couple of years now. Found it easy to install, and it has worked seamlessly everytime, apart from one, when I had one train entering the loop section at the same time as another one leaving it! Operator error - whoops.

[jpendle]

Hi,

 

I would echo what others have said and go for an electronic model rather than a relay based one. There are fewer problems as they will typically detect the short circuit faster than the DCC command station.

 

I used the Tam Valley Hex (6 way) Frog Juicer on my reverse loop. (I also used it to switch power to the frogs in 2 diamond crossings, hence using the 6 way version).

 

A reverse loop module can be thought of as two frog juicers/polarity switches in a single package.

 

Regards,

 

John P

[big jim]

Like ITG I’ve used the gaugemaster one with no issues whatsoever 

[Peter749]

Thanks Gents,

 

Peter

[SamThomas]

23 hours ago, WIMorrison said:

Makes absolutely no difference which manufacturer you choose

To a certain extent yes, but if you stick to the same make & have any issues the manufactures cannot blame "the other make".

[WIMorrison]

They cannot blame the other make as there is zero dependency on the manufacturer as long as the are all DCC.

 

Mix and match to get the performance and operation you want, don’t waste money buying a brand.

[Crosland]

21 hours ago, jpendle said:

I would echo what others have said and go for an electronic model rather than a relay based one. There are fewer problems as they will typically detect the short circuit faster than the DCC command station.

 

That's not necessarily true. Using a relay for reversing has nothing to do with short detection, which will always be electronic.

 

The MERG reverser, for example has electronic detection and switching (isolation) to cut the track power and uses a relay only for the changeover switch. I would be surprised if there are not commercial units operating on a similar principle.

 

The problem with relay switching (if problem it really is) is the switching time of the relay compared to an electronic reversing switch. It is alleged to cause stuttering in sound locos, but a decent stay-alive would fix that.

[SamThomas]

1 hour ago, WIMorrison said:

They cannot blame the other make

 

Sorry, I disagree - I have had experience in the past (& not just model railways) when having issues with getting Manufactures A kit to work with Manufactures B kit.

 

Clearly, we have different opinions about this so lets leave it there - people can then make up their own minds.

[WIMorrison]

If you can only use one manufactures equipment then you immediately limit yourself to the few OEMs who have a full and complete offering of all DCC products - and there are only 2 that immediately come to mind. If you can only use one manufacturer's equipment and keep the same 'badge' throughout the layout how do all the suppliers who only make 2 or 3 items survive as no-one will ever buy their offerings? How do you run your layout of you buy a command station from a manufacturer who doesn't make handsets? How do you change turnouts when the OEM badge you have chosen doesn't make turnout motors? How do you make your signals work? How do you make automation work?

 

The answer is simple, you don't need to stick to one OEM as all the kit using the DCC Bus is compatible, the same as all LocoNet equipment is compatible, as is all equipment using XpressNet, or ...

 

 

[GoingUnderground]

In respect of reversing modules that work by detecting the short when the loco crosses the boundary between the loop and the rest of the layout, the reversing module must work faster that the short detection on your command station or booster feeding the loop and entry/exit. If the module is too slow then your command station and/or boosters will cut the power before the module has removed the short by switching the polarity. This holds true for all reversing modules and all command stations.

 

Modules that simply use a traditional electromechanical relay triggered by the short to reverse the polarity will be too slow to stop command stations and boosters that use solid state electronics detecting the short and cutting the track power. This is something with which many DCC users will be familiar.

 

Many older designs of command station and or booster use relays themselves may well work without problems with relay based reversing modules.

 

But if you have a command station or booster that itself uses solid state electronics to detect and cut the track power when it detects a short, then you either have to use a reversing module that also use solid state electronics or a composite design as Crosland has described above, or one that uses a trigger other than the short to change the polarity of the loop.

[GoingUnderground]

The debate over sticking to the same manufacturer is not a simple as the two opposing views described above.

 

The NMRA standards cover the interaction between command station or booster and loco and accessory decoders.

 

There are no other formal manufacturer independent standards that I know of.

 

When it comes to using additional throttles, occupancy detection modules and anything else that exchanges data with the command station then you need to make sure that the throttle or module uses the same data communication protocol as the command station.

 

There are two proprietary communication standards that have wide acceptance, Xpressnet from Lenz, and Loconet from Digitrax. Other manufacturers have adopted one or other or sometimes both of these standards, sometimes in parallel with their own communications standard. One example of less widely adopted comms standards is ESU's ECoSLink which is used only by ESU and equipment that they have designed for other manufacturers. Another is MERG's CBUS, and I think that Maerklin's is now diverged so much from ESU's ECoSLink that it is now another independent standard.

 

In theory if a command station from one manufacturer and a module from another manufacturer both use the same comms standard then they should work together, but that depends on how closely each of them have implemented the standard. Thus, Xpressnet from A should work with Xpressnet from B, and Loconet from C should work with Loconet from D. In the case of Loconet, it is slightly more complicated as there is a Loconet-T standard that works only with throttles and occupancy detection but not boosters, whilst the Loconet-B works with all peripherals including boosters.

 

But remember it all depends on how closely each manufacturer has stuck to the respective standard whether kit from different manufacturers will work together satisfactorily.

 

However, many bits of DCC kit do not rely on communicating with the command station, and this often applies to reversing modules. Many of these simply sense the short and reverse the polarity and so should work with any command station, subject to the need for the module to react faster than the command station's own short-circuit detection. The same applies to power district circuit breakers and frog juicers which do not have any command station interface and so should work irrespective of the command station. For example, the Lenz LK200, referred to earlier, works without problems with ESU's ECoS and CabControl systems.

 

Some modules do require an interface with a command station and will not work without it. So it always pays to make sure that you understand the requirements of your command station and of any module you are thinking of buying before you buy the module to avoid disappointment. 

Edited May 31, 2021 by GoingUnderground

[RAF96]

I have used the Hornby RLM which has a switch to set trip current sensitivity, marked oddly Select and Elite, really meaning which level of overload/short method it sees, the PSU or Controller. Handy to have the ability to select hi or lo.

[SamThomas]

2 hours ago, GoingUnderground said:

The debate over sticking to the same manufacturer is not a simple as the two opposing views described above.

 

Indeed, I expressed my opinion (based on experience) & left it at that for others to make up theuir own minds.

 

However, there will always be one or two that will pick over the bones to the nth degree to have the last word.

 

FWIW, I agree with what you say & in any case, AFAIK NMRA does not cover every aspect of DCC.

 

In the future I can see a European split away from NRMA as new developements come along.