DCC for dummies

[Vecchio]

15 minutes ago, DaveArkley said:

 

 

And please look at the Digikeijs DR5000, in my view the best value pound for pound system out there. But that's my view, buy what suits you best.

 

Cheers

Dave

Cannot be bad as they are using the Roco Z21 app for wireless control

[tigerburnie]

I'm in north east Scotland, so a bit of a model shop desert really, one shop in Kirriemuir and small one in Dundee, there are model clubs in Dundee and Aberdeen as well as Perth, so I hope to get some first hand advice at the Perth Exhibition later this year. I know a lot of you guys have personal experience, so I thought I'd ask before jumping in, unlike my DC layout where I just ploughed in making mistakes, but at least I have learnt and should make a better job of the next project.

I originate from the east midlands, burnie is my nick name and the Leicester Tigers are my home towns rugby team(I'm an ex rugby player myself) hence the handle.

My first job is to get the summerhouse de-cluttered then build the bases, then I will really be asking the daft questions when the track has been laid(with lots of droppers and a bus bar system) so you've got a couple of months of quiet I would think.

[DaveArkley]

4 minutes ago, Vecchio said:

Cannot be bad as they are using the Roco Z21 app for wireless control

Indeed they are, and since the DR5000 supports both XpressNet and LocoNet at the same time you have a very wide choice of hardware throttles if that is you preference. I personally use a mix of Fleischmann Profi-Bos throttles and assorted phones and tablets running the Z21 app.

 

Cheers

Dave

[Phil S]

An answer needs to be self-complete - especially if read out-of-context  or sequence - and  especially where 'safety' may become involved.

The reader is always entitled to skip read parts or the entirety !  It is not done to 'show off' - but make relevant information available. Posts are also read by other than the OP - and as  is often commented, the OP frequently omits essential details such as gauge etc.

 

Sometimes it is necessary to counter errors in terminology: most frequently 'Power District' perhaps, and Polarity - where Phase is more appropriate for an ac signal (and then we get the readers who insist that dcc is a dc signal !!)  Perhaps 'red and black' wires are best avoided to avoid confusion with 'dc''s positive and negative - although if applied literally on analogue, such a train would only run one way 8-)

 

When converting an existing analogue layout to digital; don't forget to remove any capacitors fitted to track-power feeds!

(Commercial power feeds NEED these, to comply with interference regulations - even if many 'home-builds' omit them 8-)

If left in, they become an effective short circuit of the (ac) digital signal. [ Do not confuse with any capacitors inside locos/after decoders! ]

 

[A POWER DISTRICT has its OWN power source: Multiple Power Districts:-  EACH have their own independent Power Supplies. Isolation between POWER DISTRICTS MUST be of both rails.   SUB-DISTRICTS are 'isolatable sections' WITHIN a 'Power District' (EG The Central Controller, or 2nd 'Power Supply+Booster' - and although they MAY be isolated only on 1 rail, it is 'better' to gap both. 

'Sub-Districts' are useful to separate parts of the layout - for example for fault-finding, or current limitation (EG with PSX circuit breakers - and is most common to separate 'the 'accessory bus' from the 'track' (or tracks busses/sub-sections) - thus avoiding the problem of a track short circuit such as a derailment, or obstruction, preventing points and signals  from being changed - hopefully clearing 'the problem'.

An analogy is to the FUSE BOX for your mains wiring: 1 Incoming Feed, separated and protected by breakers into low-limit sub-('districts')

 

Whilst a 'small' layout is unlikely to need 'Multiple Power Districts';  they may well benefit from SUB-DISTRICTS including the separation of track and dcc-controlled Accessories. HOW MUCH power is also dependent on a variety of factors.  MANY System controllers can offer 3-5A maximum. IF POINTS (solenoids) are powered from a separate (eg 16Vac) power supply - even though dcc controlled by accessory decoder, they do not add to the total dcc power needed.  Equally 'size' does not matter - but how many locos, sound fitted locos, and illuminated coaches are likely to be in use at any time.  Mainline or Country Branch might be a better observation.   GRADIENTS - which perhaps feature rarely on most UK layouts, add a considerable current demand increasing with train length/weight. [Triang layouts used to be designed, with Magnadhesion, to climb a gradient allowing an overpass on an oval layout .. which is also why their buffer height was higher - for clearance]

 

CURRENT CARRYING CAPABILITY of your wiring:  Faults can and do occur - a factor of life. The aim should be to minimise the risk to life etc.

Wiring appropriate for a '1 Amp' layout section (a typical analogue scenario) may not be appropriate for use under DCC if a 3 -5 Amp system is installed !!  (Would you wire a kettle with a lamp's twin flex ?? - hopefully not).   BUT if each sub-section is protected by a cutout (eg PSX/ circuit breaker set at 1-2A)  then there need be no problem retaining the original '1 A' wiring.   THE TEST is often known as 'the coin test' - it is simply to apply a short circuit at ANY part of the track/section/district, and ensure that the nearest CUT OUT ( Central Controller or more-local circuit breaker ) trips - preferably leaving everything else running.

 

COMPLICATED OR REPETITIVE ??  DCC  [or CANbus etc] can be used to control accessories - independently of the track power/control system:-  Perhaps in the eye of the viewer -  Is it 'complicated' to use the idea of  a 'module' or box fed with '2 wires' (and possibly external power), located conveniently nearby, which then has several sets of [3 wires]  going to point motors ... all using the same 3 colours eg Red,Black, Green, .... now repeat at the next junction.. and the next  ....  and when you get to 130 you'll be practiced 8-)

The alternative is to wire back to a central location, each with 2 or 3 wires, and a unique path - which may cross several 'board joins'....8-(

The DCC/ control bus approach also makes modifications of the layout at any time in the future a practical idea, rather than a nightmare.
 

CONVERTING LOCOS -  One at a time - avoids mixing up screws and losing bits.  With a basic knowledge  of ohm's law, and a multimeter the price of a single decoder to confirm connections,  OR their lack of. Decoders can be fitted to 1 or 200, or 700 locos ... just not all at once.

But its a lifetimes hobby - to do as YOU wish - just keep it safe and enjoy a long life.  As a percentage of loco cost, they are quite low.(silent)

 

Some of the 'complications' experienced are related to a particular brand of component - there are other readily available makes - and this applies to both trackwork and other items  -  lots available 'plug and play' from the major  European manufacturers (including UK).

 

THE FUNDAMENTAL CHOICES - which may need some 'research' if coming from 'analogue': are the preferences of fixed-position operation or the flexibility to move freely and wirelessly around a layout - in which case control of accessories from the handset/device becomes of more interest.   IT IS ALSO A TOTALLY SEPARATE PROGRESSION to go as far as 'Computer Control' - it is not compulsory, but many like it or SOME little bit of 'automation'.

[Izzy]

5 hours ago, tigerburnie said:

If for example I used one of these, is one enough or do I need two, one for each line or will this one unit power the whole layout via a bus bar and droppers and then select each individual loco as required?

 

https://railsofsheffield.com/products/36466/gaugemaster-dcc06-any-scale-dcc06-prodigy-express-wifi-digital-control-system

 

Simple answer, no just one, and yes, and yes.

 

You only ever have one command base station for any layout. If it doesn’t have enough amperage for the size of the layout I.e. the number of locos running at the same time, or perhaps lots of accessories being powered through it, then the normal course is to add a ‘booster’, which just does what it says, raises the amperage by adding more to that provided by the base station. This can be done in different ways depending on what is needed, using multiple boosters if necessary.

 

However, you have already stated that you intend to just use DCC for running your locos with the rest done separately/manually, (which is how many do - including myself), so I would say that what you have there might suit you quite well. This is because the express handset doesn’t allow accessories to be controlled - which you don’t need - but does cover both program track and programming-on-the-main (POM) along with cv read back. The 1.6amp output should be more than enough to run several sound locos at once, plus the wi-fi unit will allow any android/apple phone/tablet to be used as additional throttles via the available apps.  To my mind this recent package is quite good value. Simple to set up and quick to use - no waiting for things to go through a boot-up regime, ( although I suppose the wi-fi might - not sure on that aspect).

 

When I first went DCC it was with a DC layout, which was ‘converted’ by taking out the DC  feed, putting in the DCC, and leaving all the section switches on. I did of course put chips in the locos......

 

So I would suggest you wire the track basically as you would have for DC, just joining all the ‘sections’ together as one big one by using the bus bar and droppers.

 

Izzy

[tigerburnie]

Thanks Izzy, due to constraints on the size of the layout, I cannot see how there would be more than 3 locos "in action", to that I mean one or two moving and one simmering either in the yard, or at a halt at the station, the odd whistle when a train leaves the station, enough to keep me and two young grandsons amused, they will want to have a button to press, so a handset that isn't fixed down would be cool. When on my own it will be a coal train arrives at the yard, a bit of shunting of wagons, the loco then goes over to the other side and picks up some wagons and off it goes to the fiddle yard. Every now and then a train would pass on the through line to give the glamour of the ECML in the 1950's/1960's and will include a diesel or two to add to the reality of the changes back then. So a fair bit of attention to detail on the landscaping of the station and yard and the sounds to add to the movement to add an atmosphere of a time long gone.

[Art Dent]

51 minutes ago, Izzy said:

This is because the express handset doesn’t allow accessories to be controlled - which you don’t need - but does cover both program track and programming-on-the-main (POM) along with cv read back.

 

I had a Gaugemaster Prodigy Express from new and in my experience, the read back of CVs was problematic.  I took the base station, power supply and throttle (cab) back to the shop and they tested it and they couldn't get it to reliably read back CVs either - they tried the loco I took along with me to demonstrate the problem as well as two others that they took from new, boxed stock.  The Prodigy wouldn't reliably read the CVs of those locos either.  They then tried another brand new, boxed, Prodigy Express system and that wouldn't reliably read back the CVs of the three locos either.

 

On that basis, they refunded the cost of my prodigy system - even though by then it was 6 months old - as it didn't do what it was advertised to do.

 

I then purchased a NCE PowerCab system for around £10 more (from a different supplier as the shop that sold me the Gaugemaster system don't stock NCE) which does everything the Gaugemaster Prodigy did - with the exception that the NCE PowerCab doesn't have a separate output for a programming track - and I'm very happy with it.

 

This, of course, may not matter to you, but my experience is that the Gaugemaster Prodigy didn't read back CVs.  Other than that, it was a good and very user-friendly system (as is the NCE I bought I hasten to add).

 

I frequently run two or 3 sound-equipped locos on my test track with the NCE PowerCab with no issues.

 

Hope this helps,

 

Art

 

EDIT: One further point is this.  Visiting model railway exhibitions have a look how many layouts are running NCE PowerCabs (or the more powerful ProCab version or Digitrax or Lenz, etc) systems and how many are running the Gaugemaster Prodigy.  You won't find many Gaugemaster systems you'll find.

 

Edited February 26, 2019 by Art Dent
Additional info and clarity

[RAF96]

From memory the Prodigy is a controller that needs time to read decoders. The screen may say its done it but the internal gubbins is still in work, so patience is the virtue with that controller.

 

I may be confusing it with a similar controller variant but its worth twiddling your thumbs a bit just in case before condemning readback failure.

[Art Dent]

33 minutes ago, RAF96 said:

From memory the Prodigy is a controller that needs time to read decoders. The screen may say its done it but the internal gubbins is still in work, so patience is the virtue with that controller.

 

I may be confusing it with a similar controller variant but its worth twiddling your thumbs a bit just in case before condemning readback failure.

 

Didn't know that but neither myself nor the shop had any success on reliably reading back CV values and the shop (as far as I remember because this is about 2 - 2 1/2 years ago now) even phoned Gaugemaster and they couldn't offer a solution - hence the shop gave me a full refund because it 'didn't do what it said on the tin'.  Of course we may have been just very unlucky - but trying three different locos with decoders by different manufacturers and two different prodigy systems and getting no reliable read-back seemed to say it all.  

 

What would happen is it would read one, two or even three CVs then fail (can't remember whether there was an error message of just a blank display).  Unplug the power lead, count to 30 (to allow any capacitors to discharge), apply power and attempt to read CVs again - same thing, two or three tops then fail.

 

If reading back CVs isn't important to you or you have some other way of doing it then fine, it is a nice system to use - even if the 'Hall effect' rotary throttle dial doesn't always register exactly how far you've turned it.

 

The NCE PowerCab does everything the Prodigy did - with the exception of no separate program track output (which was quite useful) and no backlit display - and I'm very happy I was able to make the switch.

 

Hope this helps,

 

Art

Edited February 26, 2019 by Art Dent
Splelling!

[Izzy]

I must confess I have never really tried read-back with my PA2 since I only POM with it, using a Sprog for most program track decoder programming. I aught to try it sometime I suppose just to find out. Don’t know how popular the MRC/Gaugemaster system is either, or indeed if it matters, but the back-up service I’ve had from Gaugemaster has been first rate, having duffed it up a couple of times! So that is one plus factor in that respect. Do think it is often very difficult to make a comparison choice between the systems available, non of which are probably perfect in all areas and each with their own little foibles.

 

Izzy

 

[Andymsa]

10 hours ago, Ron Ron Ron said:

 

The "modification" is simple, child's play.

Peco give clear simple instructions about what needs to be done.

There are other manufacturers whose points are ready to lay without needing any changes (e.g. Tillig).

Most hand or kit built points would be built this way in the first place.

 

 

.

I extensively use tillig points and I can say they need additional bonding wires as well, there double slips points are an extreme challenge to say they least. One issue I have found with the tillig double slips is there can be a short at the frog if the wheel back to back is a little tight. Although I have found a solution to this.

[Pete the Elaner]

54 minutes ago, Art Dent said:

The NCE PowerCab does everything the Prodigy did - with the exception of no separate program track output (which was quite useful) and no backlit display - and I'm very happy I was able to make the switch.

 

PowerCab does have a backlit display. If yours does not then maybe it is faulty?

 

It is a very modular system to keep costs down:

If you want a separate program track then there is a separate board available which provides it.

If you want to connect a computer then a separate USB board is available.

If you want more power then a booster is available.

[trustytrev]

Hello,

      From some of your experience earlier in life you might care to look into MERG. From your  posts it appears you already have the skills to easily make an informed decision with information available there.

trustytrev.

[Junctionmad]

Can I just say 

 

1. You don’t “ need” to modify points 

2. You don’t “ need” to run DCC busbars and droppers to everything , you can use fishplates

3 you can get quality DCC decoders for around £20

 

 

[Junctionmad]

To take issue with PhilS 

 

the NMRA DCC standards don’t mention the term “ phase” in relation to DCC waveforms , they use the term unipolar and bipolar , and they do indeed refer to positive and negative 

 

there is is no mention per se of Districts or sub-districts in the DCC spec , this is nomenclature from some particular manufactures 

 

a “ district “ in DCC is NOT necessarily the output of an independent booster , by and large a district on DCC is understood to be an area of track under individual short circuit control 

 

hence MERGs short circuit protection device is called a DCO, or District cutoff , so many power districts may in fact be under the control of a single booster 

 

the use of the term sub-district is again manufacturer specific and is not referenced in any NMRA specs. 

 

Not disagreeing with the usefulness of your nomenclature , but it’s in no way applied consistently like you suggest 

 

AC by definition means alternatiing current , a DCC signal can be a unipolar dc pulse train , a dc bipolar pulse train or , yes considered AC , it all depends on the reference being used at the time , it’s of course convienent for beginners  to use the term AC , but that’s not always correct and in general terms electronics engineers don’t use the term AC when describing  pulse trains , it would be more common to refer to bipolar signals etc. https://en.wikipedia.org/wiki/Bipolar_signal

 

Dave 

Edited February 27, 2019 by Junctionmad

[Andymsa]

8 hours ago, Junctionmad said:

Can I just say 

 

1. You don’t “ need” to modify points 

2. You don’t “ need” to run DCC busbars and droppers to everything , you can use fishplates

3 you can get quality DCC decoders for around £20

 

 

 

Yes you don't need to modify points, but best practice to do so.

fishplates only now this is asking for trouble, if there is too much resistance due to only using fishplates the dcc system won't shut down with a short

[tigerburnie]

Well I do have a lot of information and opinion, what I will do is look closely at what my proposed layout will actually need and apply said info. Off the top of my head it would seem there will be distinct areas to the layout, the down line and two sidings, the up line, the coal yard and finally fiddle yards at each end. Sound will actually only be needed on the display areas, but as there will be more than one loco on each fiddle yard track, it will still need to be DCC to function as I envisage it to work.

[Pete the Elaner]

39 minutes ago, Andymsa said:

 

Yes you don't need to modify points, but best practice to do so.

fishplates only now this is asking for trouble, if there is too much resistance due to only using fishplates the dcc system won't shut down with a short

Dave posted minimum requirements & in many cases, you can get away with these & the layout will work.

You have stated recommendations which I agree with & use.

 

From reading many threads on here, it sounds like minimum requirements are fine for DC but recommended practices should be followed for DCC.

 

This gives a false impression. The recommendations you make are equally valid for DC & would produce a more reliable layout than not following them. I have followed these practices for a DC layout & it runs much better than its predecessor ever did.

Edited February 27, 2019 by Pete the Elaner

[Izzy]

25 minutes ago, tigerburnie said:

Well I do have a lot of information and opinion, what I will do is look closely at what my proposed layout will actually need and apply said info. Off the top of my head it would seem there will be distinct areas to the layout, the down line and two sidings, the up line, the coal yard and finally fiddle yards at each end. Sound will actually only be needed on the display areas, but as there will be more than one loco on each fiddle yard track, it will still need to be DCC to function as I envisage it to work.

 

I have just looked at the Prodigy Express handset compared to the Prodigy Advance 2 that I use. Had no problem this morning connecting up a program track and getting read-back of cv's, but......... it was quite clunky to use, and it appears the PE handset is more restricted as to how it works in this respect. This is quite clear in that it also only has functions F0-F15. Now IMHO this means it is probably not really suitable for use with sound locos. I know other systems also often have issues in this area, only the latest versions of some offering the full F0-F28 range. Okay, I don't often use more than the basic ones when running a loco, but not being able to access some higher ones may prove awkward at a later stage if you end up getting a 'full fat' sound loco/install - Zimo with active/immersive drive etc -  which you might. Actually the use of smart phones/tabs via engine driver/Wi-throttle would probably offer more features in this respect, ( it might apply to the programming/cv read-back as well). I have both apps loaded on different phones/tabs but have never really used them so can't say. But something to be aware of when trying to balance out the individual systems one against the other.

 

Izzy

 

 

 

 

[Oldddudders]

It is so sad to see a good thread go bad. Most of the first page was earnest stuff trying to help the OP, but it has descended into the “I know best” and “Your method and system are pants” level that DCC threads so often do. Please ask yourself if what you are posting is germane to the OP’s search for what many of us see as a great way to run a layout. Not all of the recent stuff comes near.  

[Andymsa]

16 minutes ago, Oldddudders said:

It is so sad to see a good thread go bad. Most of the first page was earnest stuff trying to help the OP, but it has descended into the “I know best” and “Your method and system are pants” level that DCC threads so often do. Please ask yourself if what you are posting is germane to the OP’s search for what many of us see as a great way to run a layout. Not all of the recent stuff comes near.  

 

Very true indeed, I'm not surprised the OP has not thrown his arms in the air and ran off into the distance whaling like a banshee.

 

so my advice to the OP is forget what's been said in the thread and look at a web site http://wiringfordcc.com/ this way the OP won't get 50 ways to do the same thing as we all have our ways off doing things.

 

the only thing for he OP to decide is what DCC system let the debating begin:)

Edited February 27, 2019 by Andymsa

[Sir TophamHatt]

20 hours ago, tigerburnie said:

I kind of hoped the above Gaugemaster might have been sufficient.

This is why I opted for the Gaugemaster rather than the NCE.   There was also some murmering about using the power booster with the NCE in the UK invalidates warranty, but I may have read it wrong.

 

 

Also worth noting from the above few posts:

> Prodigy Express (cheaper version).

> Prodigy Advance 2 (full version).

 

I have the PA2 and don't have any problems reading back values of CVs.

I also do this fairly frequently, although will probably do it less now I've invested in a SPROG.

Edited February 27, 2019 by Sir TophamHatt

[Crewlisle]

Summing up all the previous comments, you can make DCC as simple or complicated as you like.  I converted my 00 gauge layout 'Crewlisle' from DC to DCC in 2008 when it was 40 years  old using a Lenz LZV100 command/power station, two LH90 handsets & a LKl00 reversing module for my reversing loop.   I retained my 30 Peco solenoid motors (20 of which are of the old original cylindrical design) operated via a CDU & 'stud' operation on mini track diagram panels.  Besides the basic requirements for DCC operation, the only additional 'extras' I have fitted are two PSX-1 circuit breakers - one for the high level & one for the low level.  If a short occurs in one, the other half is still operational. 

All track is Peco Code 100 together with Electrofrog Points & the last of my Insulfrog points  I had converted to live frogs.    The only polarity switch on the layout is for the live diamond.  All points rely on blade contact as when I fitted most of them there was no such thing as 'frog polarity switching'.  Over the last 10 years the number of point shorts/stalling I can count on one hand both at home & at exhibitions.  My 50 locos still have their original capacitors connected & apart from the 10 sound decoder fitted locos, all decoders are a mixture of Bachmann, Hornby, Lenz or TCS.   I have only managed to 'fry' two decoders!

By today's standards, my set up is prehistoric!  If it ain't broke, don't fix it.

 

I posted the above comment on 24 February in the forum 'To DCC or not to DCC?'.  One further comment I would like to make is that articles I had read in modelling magazines before I took the 'plunge', gave the impression you required a degree in electronics!  It is no more difficult than wiring up a DC layout, but a lot more expensive.

 

Peter

[Junctionmad]

2 hours ago, Andymsa said:

 

Yes you don't need to modify points, but best practice to do so.

fishplates only now this is asking for trouble, if there is too much resistance due to only using fishplates the dcc system won't shut down with a short

Nonsense , quite frankly , good practice yes , but I have a friend whose large layout is run on DCC ( NCE pro ) where most of the connectivity is by fish plate , because he merely converted from DC to DCC by closing all his section switches. 

 

Weve tested the short circuit , via fishplates , works fine 

 

Its been running fine for several years 

 

it’s it optimum , no

 

does it work ,  very  definitely yes 

 

 

[Andymsa]

11 minutes ago, Junctionmad said:

Nonsense , quite frankly , good practice yes , but I have a friend whose large layout is run on DCC ( NCE pro ) where most of the connectivity is by fish plate , because he merely converted from DC to DCC by closing all his section switches. 

 

Weve tested the short circuit , via fishplates , works fine 

 

Its been running fine for several years 

 

it’s it optimum , no

 

does it work ,  very  definitely yes 

 

 

Are the fish plates soldered ?

 

Can turn out to be expensive nonsense, yes it well may work but not all layouts are equal from a lose fitting fishplate to paint ingress and oxidation many aspects can effect fishplate conductivity and induce a high resistance.  

Edited February 27, 2019 by Andymsa