Addresses - how much address capacity required?

A loco with sound lights and smoke still only needs one address. Even a DMU with a chip at each end will only need one address (both chips are set to the same address).

Consists also require an address (at least in some systems), but you won't have many of these.

For your points you need at most one address per point.

So you need rather less than 100 addresses in total.

Many people like the loco address to be related to its TOPS number (or equivalent), so it is probably better to be able to control 5087 by that number instead of just 87, but if you also have 43065 you will have to drop some digits so why not just use the last 2 for all?

On the subject of 43065, the dummy power car is (I think) 43085, but the function only decoder I have in that unit is set to '65'. If I fitted a motor to it I would number it as 85 and run the train as a consist / multiple unit.

>And I would like to consider return loops so does this feature use up address capacity?
As I understand it, these not inexpensive devices, are attached to the track power and detect the short when the train wheels bridge the gap on entering / leaving the return loop. Once the short is detected, they swap the polarity of the feed in the return loop which removes the short. All this in the blink of an eye, which maybe explains the cost.

>I may have a pool of chips which I can move around depending on which locos I want to have a DCC play with.
After Doug's review on the Hornby Britannia and other people's experience with the Hornby A3, I think your options are limited to:-

1) Permanent chipping these exceptional locomotives
2) Not buying them at all
3) Fitting an extension harness that goes back to the tender and having a socket in there which you drop something like the cable free Lenz Silver into - just lift the coal off, and hack out the insides of the tender while you're at it
4) Stick with DC.
5) Build a Z gauge layout in a brief case

David

Gary,

QUOTE (Gary @ 19 Oct 2006, 22:42) <{POST_SNAPBACK}>How about practical answers to practical questions.

Now given that I class myself as an average proprietory home hobbyist playing with transient set track layouts my largest ever home layout had 19 points, 8 signals and had 6 trains on the track at any one time. This was an exception and 10 points is more the norm.

How many addresses would I need to have this all under DCC control?

Even with DCC it will be impossible for me to ever have more than 19 points and maybe a maximum of 10 trains somewhere on the layout.

My layout is 7M x 4m. It is primarily a scenic layout and not the traditional throw as much track down as one can type of layout, so it is fairly simple in the scheme of things.
There are still about 35 turnouts (18 in the fiddle yard) and about 40 signals, all fully operational. It can be operated with about 14 trains on call at a time. There are three throttles, so the likelyhood of running any more than 3 trains at a time is fairly low.
So if one combines turnouts, signals and locos, my count above is about 90. But that does not include my other 30 locos or any spare addresses for loco studd expansion or visitors.

My own view is that DCC should stop hanging on to old 1980's technology and have a quantum leap upgrade. 32 bit processing should be the norm and then you could apply what ever address you wanted and have a massive address range.

QUOTE (Gary @ 19 Oct 2006, 22:42) <{POST_SNAPBACK}>OK I may have more than 10 locomotives but I would never go out and buy a chip for them all. I may have a pool of chips which I can move around depending on which locos I want to have a DCC play with.

This is one of the popular 'urban myths' put around by non-DCC users. In practice, it never happens and every loco ends up with its own decoder.

QUOTE (Gary @ 19 Oct 2006, 22:42) <{POST_SNAPBACK}>Another question. Does a loco require more than one address reserved if sound and lights are fitted?

No, it all works off of the same address.

QUOTE (Gary @ 19 Oct 2006, 22:42) <{POST_SNAPBACK}>And I would like to consider return loops so does this feature use up address capacity?

No, these are based on short detection (rather a fudge solution in my opinion) and do not require an address.

Menu as requested:

Locos - 1 address each (includes sound, lights etc - extra functionality is handled by 'functions')
Turnouts - 1 address each, crossover can be paired under one address and decoder
Signals - 1 address each (semaphore). DCC really doesn't handle MAS
Feedback - 1 address for each device (input and output are normally separate address ranges)

Graham Plowman

QUOTE Another question. Does a loco require more than one address reserved if sound and lights are fitted?

No but it has the advantage of having the decoder already fitted.

QUOTE Now given that I class myself as an average proprietory home hobbyist playing with transient set track layouts my largest ever home layout had 19 points, 8 signals and had 6 trains on the track at any one time. This was an exception and 10 points is more the norm.

How many addresses would I need to have this all under DCC control?

You would only need two as a bare minimum but then you would have a basic obsolete system with no room for expansion.

QUOTE OK I may have more than 10 locomotives but I would never go out and buy a chip for them all. I may have a pool of chips which I can move around depending on which locos I want to have a DCC play with.
You've obviously never fitted a decoder to a Hornby steam loco, as mentioned previously see Dougs efforts with the A3 and Brittania. You're only going to put yourself through this once. As I mentioned elsewhere to fit a decoder to a Hornby steam loco you're talking several hours as opposed to European locos where it can actually be seconds. In reality no-one is ever going to do this.

All these questions are really missing the point though. Yes you will get by with a two digit address system but it is not an international standard. It's a bit like buying a Betamax video it will work but no one else is using it. At the end of the day to a non DCC user a two digit addressing system may seem ok but once you learn about what you're doing and your limitations you probably will regret it.

QUOTE Yes you will get by with a two digit address system but it is not an international standard.

There is not really an official international standard on this. The NMRA standard does not cover this area.

Am I right or wrong?

Really this topic is designed to help the newbee such as me who is likely to get confused by all this recent talk of addresses.

Have no doubt that I am after a Hornby Elite unit as this should be more than OK for my own personal needs with the 255 address capacity. I like the idea of a link to a PC, the extra power as standard and the ability to call up a loco by name. I do have one on order for £92.50 from Ontracks.

All we want to know is how many are actually required for a typical British home layout. I accept layouts produced by modellers outside the UK are going to be a lot bigger and may well require a DCC set up to match.

This is not really a discussion about 2 or 4 digit addressing.

The points made about fitting decoders is valid and if they are just £8 to £10 then its not so bad is it. The days of undoing 1 screw to remove a body have long since gone with the latest Brit products and older 1 screw products are not DCC ready.

Happy modelling
Gary

Hmm. Confusion reigns.

How about creating a definitive list of DCC features and the number of addresses required with a range offered if this is variable.

Lets start with this list:-

Steam Loco
Steam Loco lights
Steam Loco sound
Steam Loco smoke effect
D+E
D+E lights
D+E sound
D exhaust fume effect
Coach lights
Coach sound
Wagon lights
Wagon sound
Points/turnouts single slip
Points/turnouts double slip
Signals semaphore per control rod
Signals light 1 colour
Signals light 2 colour
Signals light 3 colour
Turntable
Uncoupler ramp
Return loop
Isolated track section power on/off
Loco inertia setting start
Loco inertia setting stop
Route setting
Scenic accessories
Set up loco address on special track
For link to PC
For additional cabs (portable control consoles)
For cab plug in fixed network

Now are there any other features that can be controlled by DCC and if there are please add to the menu.

Would somebody be brave enough to put address quantities required to the features in the range 0 to 10 or higher. This could open up a whole new discussion of course!

However this sort of guide should help us all to work out how many addresses we are likely to require for a given layout.

Happy modelling
Gary

Even a 2 digit system has enough addresses for quite a large layout, you just may not be able to use the preferred number with a given loco (and even that doesn't matter if the system supports alpha numeric labelling like the new Hornby kit).

My now old Compact supports 100 loco addresses and another 100 accessory addresses (that is points and other items). For the old Roco system the 100 address limit was for locos and accessories combined.

Everything in a loco can be done with a single address --- it is just a matter of using a decoder that supports enough functions. If you need to control more lights independently than say a 6 function decoder permits, you can add a second decoder on the same address at get its to respond to a separate range of 'function' ids.

Which raises a separate issue; my Compact can only control functions F0, F1, F2, F3, F4. Other systems can control many more functions (13 or even more). Functions can be used for controlling lights, smoke units, opening doors, releasing couplings, sounds (this can use a lot of functions), raise/lower pantographs, ... For example, my class 24 has sets of yellow and red lights and front and rear all controlled independently by F0, F1, F2, and F3 (front yellow, front red, rear yellow, rear red).

QUOTE Steam Loco
Steam Loco lights
Steam Loco sound
Steam Loco smoke effect
D+E
D+E lights
D+E sound
D exhaust fume effect
Loco inertia setting start
Loco inertia setting stop
All this is a matter for the loco decoder (just one address), although inertia could also be managed by the control system.

QUOTE (Doug @ 20 Oct 2006, 07:21) <{POST_SNAPBACK}>A couple of the posts above say for turnouts you need one address per turnout.

You actually need one address per turnout decoder. Most decoders handle 4 turnouts, some handle 6. If you can put enough amps through the decoder, you can power two turnouts per outlet as long as the points are paired as in the case of a mainline crossover.
I said you needed at MOST one address per turnout (actually two for something like a 3 way switch).

While some turnout decoders use a single address for several outputs (each controlled by functions I believe), others, like the Lenz LK150, use an address per output.

So depending on the decoder we might control six point motors using addresses 1 through 6 or by using address 1 with functions F0 through F5 (but not on a Compact which can't control F5).

So functions are a subset of addresses?

So looking at the list would it be fair to say that (for example) a 3 light signal might require 1 control address and 3 functions?

And a loco would require 1 control address and a number of functions to control loco accessories?

Maybe we need to look more closely at functions?

Should this be a seperate topic or is it a subset of this topic?

How a control console handles functions once an address is called up seems like a key area for those wishing to have all singing all dancing locomotives and rolling stock.

Happy modelling
Gary

QUOTE (Gary @ 20 Oct 2006, 11:41) <{POST_SNAPBACK}>How a control console handles functions once an address is called up seems like a key area for those wishing to have all singing all dancing locomotives and rolling stock.
Indeed. The biggest weakness of the Compact is not that it only supports 100 addresses, but that it can only control 5 functions (and two of those via a shift key). How it displays which functions are currently on is also poor.

What a function does on a given loco depends both on how you have wired the decoder and how it is programmed. So it would be nice if the command station remembered this for you and associated alpha tags with each function (on each registered loco). Then you could immediately see that on '38' F3 would ring the bell, while on 87 it controls a set of lights. As it is I should make up a card for each loco documenting what controls are available.

QUOTE So it would be nice if the command station remembered this for you and associated alpha tags with each function (on each registered loco). Then you could immediately see that on '38' F3 would ring the bell, while on 87 it controls a set of lights.

That makes sense. For each address you should be able to input a menu for each function that is in use so that when you call up the address the functions are shown as a menu under and you know exactly which button to press to ring a bell or blow a whistle or play a sound.

Something like this on the lcd console screen should appear:-

Scotsman

Whistle 1
Chuff 2
Hiss 3
Lights 4
Brake Squeel 5
Fireman 6

However I would also guess that a consistent approach when setting functions would make this relatively easy to remember, decoder permitting of course!

Happy modelling
Gary