DCC help needed please...

[Nutford]

Mike - #19, re your query about how I envisaged preventing one train catching another.

 

My intention was to use the Block Signalling module

http://www.blocksignalling.co.uk/index.php/section-controller-sec1-dc

 

That appears to do the job I want.

[Phil S]

Nutford, my bold on the quote from your last post. "...loco on route 2 now has power, so starts..."

Just to assess your understanding of how DCC works (it might help here), may I ask, how does that loco start?

 

Phil:  I think this came from my suggestion of a (6-road) sequenced storage yard - as per analogue - operated by 'power removal', AND RELYING ON (although I did not always specify it clearly ) that a DCC LOCO can be LEFT RUNNING without being allocated to a controller  {Very easy with a Multimaus etc - simply call up the next loco, without setting the first loco back to zero speed)  ... HOW MANY can be left running like this depends on the Master /Central Controller, and the number of locos in its cycle.. eg 8,16,32 or 64 (using Roco examples) ...

BUT of course, if the track the loco is on has no power  - it is stationary ... so 5 'moving' trans can be held in the storage tracks, with  the 6th actually powered and moving .... 

A Gentle start will be achieved because, when power is restored to the track,  the Acceleration/Inertia settings of the decoder will come into play .. unfortunately, this simple system cannot do gentle stops .... for that you DO need to know the Loco ID and where it is ! 

A similar system MAY be used for  TRAIN ELEVATORS or traversers  - but it would be 'better' if the stopping was controlled by dcc ....

 

OR

Yes this is possible using the Lenz braking modules, OR the 'Full' DCC  Braking section module (broadcasting zero speed to all locos in the section) - BUT THESE ALL REQUIRE a full train length to be isolated before the changeover (from 'normal running' to 'brake to a halt'  can take place

[you MUST NOT ASSUME that the loco is at the front, and that there are no metal wheels on the rolling stock behind the loco] ....

 

BUT AGAIN - a storage road WILL be FULL length - and so a (single) braking generator COULD be switched  to each track that is to be stationary - controlled by the photo detector   

 

So... ...

 

SUMARY of Automated Holding yard using a 'Braking Generator' {works on ALL dcc decoders}  OR LENZ BM modules [works on 'enabled compatible' decoders]:

EACH STORAGE LENGTH MUST BE longer than the longest train  - and MUST BE DOUBLE GAP ISOLATED at EACH END.

AN OPTO DETECTOR / Beam Break NEAR the EXIT end (with sufficient braking space) DETECTS the arriving train, and SWITCHES the POWER to the BRAKING GENERATOR  ( or witches the BM module into circuit )  ...the moving train then comes to a stop.

( A  SECOND OPTO Detector - just ahead of the exit point might be advisable - in case the train overuns the expected stopping position and fowls the points !!! )

 

WHEN a train is required to depart - the EXIT POINT /ROUTE is set, and the Braking Generator  Output is replaced by the NORMAL dcc controller output ... the train RESUMES its original speed    ......   at this time, if not before, it might be advisable to pickup a controller with that loco selected to it. 8-)

 

NOTE: Use OPTO detectors because they will detect the FRONT of ANY TRAIN and are INDEPENDANT of the track power (which is being switched)

Roco, and others, make 'Braking Generators:  THEY are the SAME as a DCC Central Controller EXCEPT that they 'broadcast' a #Speed 0# command to ALL locos

Coach Lighting would be maintained.   Directional Lighting probably unchanged ???   Sound unchanged ????. 

As they produce their own dcc waveform, they must have their own power supply and be double-gap isolated ..The CHANGEOVER to braking should ONLY OCCUR when the train is fully within the ISOLATED section ... hence using Opto detectors near the EXIT end.   

 

The Lenz BM modules are a cheaper method of achieving a braking or slowing (speed restriction) effect - and make the dcc waveform assymetric in the isolatable section - this is detected and acted upon by compatible decoders.

 

YOU MIGHT be able to make a 'Braking Module' using a Spare Roco Maus and Amplifier - with it set to 'Stop All, but with dcc power on ... or look for Open dcc kits .... 

  ....

.

[Nutford]

Well, that can work, but its ( a ) horrible as locos will suddenly stop, and ( b ) not what DCC is supposed to do.

 

DCC is supposed to have track power to all locos at all time.   Locos change their speed between "stop" and "some speed" by commands sent over the track, and the decoder changes the speed.   But, importantly, there is always power.  

So, to stop a DCC loco in any "nice" way has to be done in one of two ways:

The plus here is for 'train swapping' they will be stopped/started in the hidden track, so it won't matter if it doesn't look good... (and yes there will be easy access to it for when they stop and stay stopped!) The block working around the track is as much a fail-safe as it is a feature, and again would at least in part be hidden.

 

The Merg system you mention sounds potentially ideal - will have to look into that. I know nothing about electronics, but maybe you don't have to. The rest will need me to take more time to read and understand! In fact please realise you guys who I haven't done explicit replies to,  don't think I'm ignoring your posts or they aren't helpful - on the contrary, but there is so much info here I'm going to have to give myself a lot of time to analyse it and research it, so I'm largely just responding to questions or particular points. The rest will be weekend homework I think!

 

And Phil/Ron above - again smooth stop/starts isn't necessary in the sidings as that will be hidden.  I will have to take time to understand the rest, but sounds very helpful. The issues about type of detection are important too.

Edited November 17, 2017 by Nutford

[Ron Ron Ron]

The plus here is for 'train swapping' they will be stopped/started in the hidden track, so it won't matter if it doesn't look good...

It's not simply a matter of "looking good" and I think you may have missed Nigel's point that DCC should not be run in this manner.

DCC is designed to drive the trains (and operate accessories) and to paraphrase that old cliche again, not to drive the track.

This is not a trivial distinction, either in terms of how the control system works, nor in the conceptual way we play with our toy trains.

 

 

And Phil/Ron above - again smooth stop/starts isn't necessary in the sidings as that will be hidden.....

When it comes to routinely switching power on and off, it doesn't matter if it's hidden or in full view.

It could be argued that this is effectively a misuse of the DCC system.

There are also potential implications from the repeated application off sudden inrush currents for the health of some decoders, with the possibility (it may be remote or not) that some may start misbehaving. There's the added possibly one or two of the less "robust' variety, may eventually tire of life and pack up.

 

Mixing DCC and aspects of DC is a perfectly valid approach, but trying to get a DCC system to behave like a DC system is not the best way to go about it IMHO.

 

May I suggest that you look at some of the practical alternatives instead?

For example, I'm pretty certain that asymmetric braking such as used in the Lenz ABC method, could do exactly what you want in the "changeover" sidings.

The ABC switching could be activated by inputs from detectors or switches.

All that remains is to find a way of automatically switching the points.

 

It might also be worth considering alternative block signalling products, that will work with a form of DCC block control.

Unfortunately this is a subject I'm yet to get to grips with (although it's somewhere on my bucket list) and others will be better placed to advise.

 

I don't know if it helps, but here are a few videos (note that track power is not cut at any time).......

 

 

 

In these videos from A&H models, you can see the Lenz ABC modules in action (note since these were made, all Lenz decoders now have ABC)....

 

 

 

Edited November 17, 2017 by Ron Ron Ron

[Ron Ron Ron]

A further video and one that might answer Nutford's question.

A gentleman named Julian Coles, reporting quite literally, from his man cave.........

 

 

Edited November 17, 2017 by Ron Ron Ron

[Phil S]

Phil: My undertanding of the braking GENERATOR is that the broadcast 'Speed 0' should make each decoder slow to a stop using its decelleration CV4 setting - it was always illusrtrated beig used on the approach to a STOP signal - but of course I may be wrong, as I have always looked at them as being too expensive and impractical to use on the approach to every signal !

 

BUT the Staging/delay area / Elevator or Train Traverser IS a logical application, as by default the required train length is included, and double-gapping is easily achieved at each end.

 

The later Lenz development of the BM modules is a more economical method of implementing the same idea - but with individual characteristics as needed by each loco programmed into each decoder (eg the precise stopping distance for THAT train)

 

To follow the sequence from analogue implementations through Braking Generator to later Braking Module is a journey of increased understanding.

All require double gapped sections.    With flywheels, some locos would even slowly stop from a sudden removal of power.  And since stopping using a ZTC511 in favour of Roco years ago, I havn't had 'runaways'  - but I also use 18V SMPSs instead of the original unregulated transformers to give a constant 16V on track, and PSXs to feed each sub-district ... so they may be controlling my start ups - I would recommend the staging area 'normal' track power was via one too!     (But PSX's  - intelligent circuit breakers - is yet another new concept to introduce to a new dcc user ! 8-) )

 

Not everyone (including me) can afford or wants to go the full feedback module route (so I reduced my count from 16 to 12  8-input feedback modules on my main layout) . This process has shown that an economical method IS possible - and what its drawbacks might be - and how more recent development which are more economical to install - can produce a better version  (and especially if starting - it may be easier to ensure all locos have ABC braking.

It would even be economical to add a Lenz basic decoder (13-15GBP from Germany) to a Hornby TTS (34GBP+) so that the movement was from the Lenz (assuming that a matching start delay could be included to match the sound)

[Ron Ron Ron]

By some happy coincidence - well not really lol - I'm just down the road from Masham, ie. about 8 miles west of Ripon. Which, for any southerners, is in a place called 'Yorkshire' ;-)  

 

 

You are lucky that you are not too far away from DCC Concepts, who are located right next to the station in Settle.

They can provide advice and supply various related DCC products and control systems.

My understanding is that they're working on a system that will be able to provide a degree of automation, without the use of computer control software.

 

 

.

[Nutford]

It's not simply a matter of "looking good" and I think you may have missed Nigel's point that DCC should not be run in this manner.

 

Indeed I did Ron.

 

And many thanks for those posts and videos! Will watch them over the weekend, but that looks SO helpful! And indeed Settle isn't so very far away, will be well worth a trip.

 

I'm rapidly realising that the good news is there are many different ways of going about what I want to do. The bad news of course is that there are many different ways of going about what I want to do! ... and I have to sort out which is the best, because all seem to involve some sort of compromise or complication. I'd actually thought what I wanted would be quite simple, just a matter of 'buy brand X'. But clearly it isn't, and as somebody posted just a very good thing I came here first before going out and wasting a lot of money through ignorance.

 

On the plus side - I no longer feel quite such a fool for not having worked out how to do it from the internet research I'd done before!

Edited November 17, 2017 by Nutford

[Ron Ron Ron]

....many thanks for those posts and videos! Will watch them over the weekend, but that looks SO helpful! ......

 

 

Do watch them all and particularly the Julian Coles one, which shows how to do exactly what you are after.

 

Also note that acceleration and deceleration rates for starting and stopping, can be adjusted in the decoders. So operation can be a lot smoother than in some of the videos.

 

Cheers

Ron

 

 

.

[Mike Storey]

Mike - #19, re your query about how I envisaged preventing one train catching another.

 

My intention was to use the Block Signalling module

http://www.blocksignalling.co.uk/index.php/section-controller-sec1-dc

 

That appears to do the job I want.

 

Thanks Nutford

 

That is a fascinating and very well explained site I have never seen before. I think I could do with a few of his products.

 

As for yours, I can see how that would work but it is possible that you may need this one http://www.blocksignalling.co.uk/index.php/shop/product/view/5/51 for DCC instead? (Or its anode version). I can see how the one you selected could work with a DCC layout, but it may cause unpredictable problems. You had best check with them first. I guess if you are only going to do this with a few signals, at £23 a pop, it is not too bad. But if you are going to equip several, my method costs a few strands of wire, but has no automation of course.

[Alan Kettlewell]

 

You live not too far from me, I'm in North Yorkshire. You would be most welcome to come and have a look at my layout and what I'm doing (you could get a preview by reading my layout thread in the signature block below). It may be more than you need, and I certainly won't have all the answers, but it would give you a good intro to the capabilities available in this world of DCC.

 

Just send me a PM if you fancy a ride up - the kettle is always on and a Yorkshire welcome guaranteed. Fair warning though - following a visit you might well end up wanting more than you thought! Lol...

 

Cheers ... Alan

[Nutford]

You live not too far from me, I'm in North Yorkshire. You would be most welcome to come and have a look at my layout and what I'm doing (you could get a preview by reading my layout thread in the signature block below). It may be more than you need, and I certainly won't have all the answers, but it would give you a good intro to the capabilities available in this world of DCC.

 

Just send me a PM if you fancy a ride up - the kettle is always on and a Yorkshire welcome guaranteed. Fair warning though - following a visit you might well end up wanting more than you thought! Lol...

 

Cheers ... Alan

Thank you very much! You have a PM :-)

[Alan Kettlewell]

Thank you very much! You have a PM :-)

 

Yep, have replied.  The kettle is on ...

 

Cheers ... Alan

[peach james]

OK, looking at this from far away, I would suggest that the eventual solution probably involves a computer control system.  It also involves detection sections- lots of them !.  I've covered a bunch of what I have slowly figured out on my thread (Long Marton).  There is definitely more than one way to skin the cat with these, but I think the easiest would be ~3 detection blocks per staging track, then a realistic # for the layout portion, with all of that fed back into software.  Which software depends on how comfortable you are with "writing" code, vs using someone elses implementations... if it was me, and I was starting now, I would use JMRI.  I'm using RR&Co 5.0.4.C, which is now 2 generations behind.  (and won't ever have any updates...).  For what I am doing, I am happy with it.  I understand that JMRI would give me close to the same functional blocks to build from as what I am doing with RR&Co, but when I started JMRI didn't exist like it does.

 

In terms of DCC system, I would suggest that Lenz, Roco, NCE & Digitrax all offer the components you would need.  There are some areas to be aware of- the big one is that the throttle and feedback bus designs are propriatary, and are unique to each "set" of systems.  So, you can't use Lenz feedback units with Digitrax, for example... but you can use Lenz mobile decoders with Digitrax command station & throttles...it's the feedback and throttle bus which was left to manufacturers.  I would suggest finding a throttle you like from ^, and then go with that system.  Your local store is a good source to figure that out in- please then spend some $$$ in with them, so they will be there for the next guy.  

 

Anyway, I have to go to a concert, but I hope that helps a little bit,

James

[TWG]

A device that does most of the things that you specified in your first post is the Uhlenbrock Universal Controller (Universalsteuerung).  This can be used for a block system and also for organising a storage yard, combining feedback and a brake generator.  It needs a system with a Loconet control bus - Uhlenbrocks's Daisy system is worth a look and has a good deal to recommend it.  There are some videos on the A&H Models showing the Universalsteuerung in action.