DCC functions ... what is required?

[VicZA]

Hi All,

 

This will be a very, very simple question so please excuse the complete beginner question. What do you need to buy in order to get your train to run AND do all the built in functions like lights and sounds, etc ... is it enough to get a controller such as the Hornby R8213 or do I need to look at other/more items?

 

Thanks

Victor

[Nick G]

Some sound decoders now have up to 28 functions so if your interested in sound and lights you need a system capable of accessing 28 functions. NCE Powercab to name one of the cheaper ones.

[HLT 0109]

. . . but the controller will not do the job unless the train has a decoder fitted.  Most ready to run items do not have a decoder fitted - even those shown as DCC Ready.

 

Harold.

[johnb]

. . . but the controller will not do the job unless the train has a decoder fitted.  Most ready to run items do not have a decoder fitted - even those shown as DCC Ready.

 

Harold.

Especially those shown as 'DCC Ready'. Straight of the shelf most will be DC only and will need a decoder (chip) fitted. Has that at the club just recently, a new member wondered why the DCC controller would not run his locos which he thought had DCC fitted. The we saw the box which was labelled 'DCC Ready'! All that usually means is that it has a socket to take a DCC decoder. So he now has to get some decoders.

 

Going on to the function issue, do verify that the controller can handle the requisite number of functions, some of the cheaper ones can only access a few functions maybe 8 or 14 perhaps 16.

 

John

[GoingUnderground]

Hi All,

 

This will be a very, very simple question so please excuse the complete beginner question. What do you need to buy in order to get your train to run AND do all the built in functions like lights and sounds, etc ... is it enough to get a controller such as the Hornby R8213 or do I need to look at other/more items?

 

Thanks

Victor

The simple questions frequently have the hardest answers, and your's is one of them. You said that you're a complete beginner, so I'll try to make things as simple as possible.

 

In a word, patience. If you rush in to going DCC you run the risk of making some inappropriate for you choices of equipment and possibly destroying some decoders whilst you learn about DCC. Please don't let me put you off, DCC gives you more from your layout than DC.

 

But to answer your direct question, 2 (possibly 3) different pieces of hardware:

1. a DCC base station, sometimes called a controller, and

2. a DCC decoder in every loco, as if a loco isn't fitted with a decoder it won't work on your DCC layout, but see below.

 

If you want to control your points and signals using your DCC controller as well, the you will need what is known as accessory decoders to operate the point motors, but that's entirely optional. You can still use your old DC controller for that, provided it is only connected to your point motors, or wire in tube, or any other method, the choice is yours.

 

The Base station replaces your existing DC controller. There are many makes and models at a range of prices from good value all the way through to "HOW MUCH????". Generally speaking, the more expensive ones have extra features such as colour touch screens, twin throttles, more power, etc, etc. Some controllers have what is known as a "Loco 0" facility which will let you control a single loco without a decoder. Please do not be tempted to buy a controller just because it has that capability. Please let me explain why it isn't a good idea. DCC power is like AC. Put a loco without a decoder on a DCC layout and the loco will remain stationary, but will hum like mad. The humming is the motor trying to turn first one way and then the other as the DCC power alternates its polarity. Leave it there and sooner or later the motor will burn out as it has its full current demand running through it but without turning it isn't being cooled much by the air around it. a controller with Loco 0 biases the DCC polarity so that the loco will move, but as soon as you bring it to a halt it will just sit there and hum and overheat. Don't get me wrong, a controller with Loco 0 isn't a bad controller, but for the sake of your unconverted locos, don't let Loco 0 influence your choice of controller.

 

As far as decoders are concerned, these come in a large range of sizes, connectors, power handling and function outputs. But they all have one thing in common, one pair of wires on the decoder (the red and black ones) are connected to the pickups from the track, and another pair of wires (the orange and grey) are connected to the motor. The motor must be completely isolated from the pickups or you will destroy the decoder as soon as you turn on the power, be it DC or DCC, to the loco.

 

You also need to know the terminology:

 

"DCC Ready" means "Ready to fit your own decoder", not ready to run on DCC. DCC Ready locos have a plug and socket arrangement already installed by the manufacturer which makes it easy to convert the loco from DC to DCC. You remove the plug, often called a blanking plug, from the socket, and plug in your chosen decoder. Don't throw away the blanking plug, you will need it if you ever want to remove the decoder as without the plug or a decoder fitted, there is no electrical connection between the track and the motor. There are several different plug and sockets arrangements in use, so you must make sure that if you want to fit a decoder in to a DCC Ready loco, that you have a decoder with the right plug, see below.

 

"DCC Fitted" means the loco has a factory installed decoder and will work on DCC out of the box. Sometimes the decoder is plugged in which makes swapping it out for a different decoder easy, other times it is hard wired in. DCC Fitted locos won't have a sound decoder installed, just a non-sound one.

 

"DCC Sound" means the loco has a factory installed sound decoder and will work on DCC out of the box. Again this can be either plugged in or hard wired.

 

"TTS Sound" is Hornby's range of lower priced DCC sound decoders. Originally these were only available as a factory fit, but Hornby are now selling them as separate items. Hornby also had locos with sound decoders from other manufacturers factory fitted. TTS Fitted locos will be described as TTS Fitted, but if it has a non-TTS sound decoder the box will be marked DCC Sound.

 

You can fit separate sound modules to non-sound decoders, but that is generally not a good idea as not every decoder has the necessary connections, and the sound modules can be hard to get. Whilst it might be more expensive, it is better to replace the existing decoder with a sound decoder if you want to add sound to a loco that already has a decoder. You can always use the decoder in another loco.

 

Sound decoders come with the sound for a particular loco already installed. There are some that you can get which have sounds for more than one loco so you could swap the decoder between locos, but that isn't a good idea as often yu need to open up the loco to fit or remove the decoder. You can change the sounds installed on a decoder, but that needs special equipment which is usually specific to a single decoder manufacturer, and you also need the sound data itself.

 

The plug and sockets systems have various different names, but there are the following standard ones:

 

4 pin, sometimes called NEM 654

6 pin, sometimes called NEM 651

8 pin, sometimes called NEM 652

21 MTC, sometimes called NEM 660

Next 18, and Next 18S, sometimes called NEM 662

PLuX, sometimes called NEM 658, which comes in a range of pin numbers, 8, 12, 16 & 22.

 

None of the above are interchangeable, you can't put a 6 pin plug in an 8 pin socket, etc. However because of the way that the pins are laid out in PLuX you can fit a PLuX plug with fewer pins into a PLuX socket with more spaces.

 

Sometimes the connectors are an integral part of the decoder and the whole assembly just replaces the blanking plug, other times the connectors are on fly leads. You can cut the connector off the fly leads if you want to hardwire the decoder in to a loco if there isn't one available that comes without a connector.

 

Every DCC decoder will work with every DC controller, but most DCC controllers will not work with unconverted locos, see my comments on Loco 0 above.

 

If a decoder doesn't work with a controller, that is most likely because the controller has something called Railcom turned on, but that is easily fixed by turning off Railcom on the controller. However, itdoes mean that you won't be able to use the features offered by Railcom on any of your locos with Railcom capable decoders. If you think you might want Railcom in he future, make sure you buy decoders that the manufacturer has said are compatible with Railcom (meaning they don't have Railcom but will work correctly work with Railcom turned on), or Railcom capable (meaning they have Railcom). All Railcom capable DCC decoders will work with all DCC controllers.

 

Never connect a DCC controller and a DC controller to the same layout or you will destroy the DCC controller's electronics. If you do want to take your time and run both, you have three options:

1. Gradually buy and fit decoders to your locos, but run them with your existing DC controller until such time as you have all your locos converted, they buy your DCC controller.

2. Put the track feed to your layout through a single plug and socket arrangement and mirror that with the leads from your DC and DCC controller so that you can plug one or the other into the layout, but never both at the same time. If you do this, remember to remove all your unconverted locos from the layout before plugging in the DCC controller.

3. Have totally separate and permanently electrically isolated tracks for DC and DCC, so that there is no way that a DC loco can enter or even cross DCC track or vice versa.

 

If your into N. American or continental European models, there are a couple of things to look out for when buying locos already fitted with decoders. Some N. American manufacturers use a system called DCS which is not the same as DCC, but they do have a DCC mode so can be operated using DCC. Maerklin have their own digital protocols, one called MM which has been superseded by another called mfx and now mfx+. I believe that the newer mfx+ decoders will work with DCC. You're very unlikely to come across locos fitted with MM of mfx as Maerklin still use 3 rail and I've not seen anything about folks using MM or mfx on 2 rail systems. However, Maerklin own the Trix name, and Trix are 2 rail, I think Maerklin may be fitting mfx decoders in more recent Trix models.

 

It might sound complicated, but once you get the hang of it, it's quite easy, really.

 

Do take your time, don't jump in. If you can, get hold of Ian Morton's "Digital Command Control" in the Ian Allan "Aspects of Modelling" series, ISBN 0-7110-3152-5, it helped me get started, but that was a long time ago. There are other similar booklets round. Also read as many of the posts on here as you can so that you can learn from the experience of others.

 

Do try out different DCC controllers at model shops or at exhibitions if you can, what one person loves, others hate. (I made that mistake) Also your choice of controller will affect your choice of peripherals such as extra throttles, wireless throttles, occupancy detection, computer interfaces, etc. as there is no standardisation between controllers and peripherals, though some will work with others. Always assume that controllers and peripherals from one manufacturer will work together, but won't from different manufacturers unless that manufacturer has specifically said their their kit will work with someone else's kit.

 

As I said, I do hope I haven't discouraged you. I'm sorry that there isn't a simple straightforward answer.

 

Investing a bit of time now in finding our more about DCC before you buy anything will make the transition from DC to DCC much less stressful, and may save you making costly mistakes.

Edited August 1, 2018 by GoingUnderground

[Dungrange]

I agree with everything that has been said.  I think the only omission from Going Underground's excellent summary above is that not all locomotive decoders provide the same number of functions.  Different decoders will be advertised as having 2, 3, 4 or sometimes more functions.  Note that this is the maximum number of non-sound functions that the decoder will handle.  If you want to control cab lights, day / night running, turning off rear lights when coupled to a train etc, then you will need to ensure that the decoder you purchase can provide for all of the functions you require.

 

The only other word of warning is to check the current requirements of the locomotive and compare this to the decoder.  Decoders will have a maximum current rating for the motor (say 1 Amp) and also a maximum for each function (say 200 mA).

[dasatcopthorne]

Victor.

 

There is quite a bit to learn if you are just starting out in DCC.

 

I'm sure you realise this now having read the answers above.

 

The easiest thing to do is visit a show and ask questions from someone using DCC or better still visit a local Club if you have one using DCC.

 

I'm sure someone will be only to happy to help you. We would but then we're in Sutton, London.

 

Dave.

[cabbie37]

As far as decoders are concerned, these come in a large range of sizes, connectors, power handling and function outputs. But they all have one thing in common, one pair of wires on the decoder (the red and black ones) are connected to the pickups from the track, and another pair of wires (the orange and grey) are connected to the motor. The motor must be completely isolated from the pickups or you will destroy the decoder as soon as you turn on the power, be it DC or DCC, to the loco.

 

May I just clarify one point please? The red and black wires will connect the controller to the track. The orange and grey wires I'm assuming are the standard colours for wiring within the locomotive? Sorry if I'm being dense... I am also in the position of learning DCC from scratch having come back to modelling after many years and so much has changed!

 

Thanks for writing such a comprehensive description in the first place I have found it very helpful...

 

Hugh

 

Edited August 11, 2018 by cabbie37

[34theletterbetweenB&D]

The red and black wires connect the decoder in the loco to the rails via the pick ups.

Orange and grey are the wires from the decoder to the loco motor brushes.

 

There is no wire colour convention for the connections between the DCC controller's outputs and the rails, (because it doesn't matter!).

[cabbie37]

Ah, that's where my confusion arose. I misinterpreted decoder for controller, must pay more attention. That all makes sense now.. I was reading this in conjunction with 

 

https://www.brian-lambert.co.uk/DCC.html

 

which shows red and black wires from the controller to the track. I did a bit of speed reading/thinking and got the wrong end of the stick. All clear now...

 

Thanks for that, much appreciated...

Edited August 11, 2018 by cabbie37

[SRman]

Agreeing with all that has gone before, and I hope I am not confusing you further, but there are also more wiring conventions for the other wires or outputs from a decoder, for things like lights or other accessories. 

 

Blue is the common return for all of the  physical functions.

 

White is usually used for forward lighting, yellow for reverse. However, most commercially available models use white for the forwards (No 1 end) direction headlights AND for the tail lights at the other end, with yellow doing the headlights at the No 2 end and tail lights at the No 1 end, meaning that the tail lights cannot be switched off independently using a function button.

Other coloured wires include green, purple, pink or brown for further outputs (e.g. smoke units, firebox glows, etc.), depending on how many functions are available on the chosen decoder. 

These are not hard and fast rules as any wire except the blue (ignoring the brush wires of orange and grey) can be used for any desired extra. I wired a Hornby Hogwarts Castle for forward lamps using the white wire, and a flickering firebox glow with the yellow wire using a 2-function decoder.

Edited August 12, 2018 by SRman

[Butler Henderson]

To add to the list of decoder types the 4 pin NEM654 is meant for high power O gauge locos and the 4 pin offering by Hornby is completely different (a case of Hornby doing their own thing regardless of DCC standards).

[beejack]

Some very good advice in the posts above but so far no one has mentioned the Hornby R8213 which is the Hornby Select and is a very basic controller.

 

If you haven't already take a look at the following thread for more info.

 

http://www.rmweb.co.uk/community/index.php?/topic/136310-Hornby-select-dcc-r8213/

Edited August 12, 2018 by beejack

[Suzie]

The R8213 Select was mentioned in the OP, but I think it has been ignored for good reason. Unless you already have one I don't think anyone would recommend buying one except as a slave for an Elite!

[SRman]

Some very good advice in the posts above but so far no one has mentioned the Hornby R8213 which is the Hornby Select and is a very basic controller.

 

If you haven't already take a look at the following thread for more info.

 

http://www.rmweb.co.uk/community/index.php?/topic/136310-Hornby-select-dcc-r8213/

 

The Select is a low-cost starter set, with very limited functionality. It will not access all 28 functions of a sound decoder.

[melmerby]

Are there any model shops in your area which sell several makes of DCC equipment?

 

A couple of those that do and can demonstrate the various features of each are: DCC Supplies, Worcestershire and Digitrains in Lincoln. (There are quite a few others)

 

You really need to look and try before you buy, bearing in mind what features you may want in future.

 

e.g. will you use a PC/Tablet/phone for layout control? if so you need a system with "connectivity" i.e. USB or LAN or WiFi.

That is not right now but in the foreseeable future.

 

Keith

Edited August 12, 2018 by melmerby

[traction]

The Select is a low-cost starter set, with very limited functionality. It will not access all 28 functions of a sound decoder.

Yes it will as long as the firmware is on V1.5!

Which is better than a brand new Dynamis Ultima which can only access 20 functions and can’t be upgraded to access all functions as it’s a limitation of the hardware according to Bachmann when I asked.

 

Cheers Ian

[Butler Henderson]

Are there any model shops in your area which sell several makes of DCC equipment?

or is there a show locally to you coming up. Most layout operators will be willing to ley you try out the system they use especially if you enquire when it is quite, i.e a Sunday afternoon by which time  most operators are all too willing to let someone else operate!

Edited August 12, 2018 by Butler Henderson