Perhaps cos no one has told them of a problem, so far its been if you try
and use the system incorrectly it wont work.
Or perhaps there so many enthusiastic retailers giving extra help to their
customers out of the goodness of their hearts that hornby just dont want to
interfere. Isnt that nice ?
How would you define an over specified system?
In my experience one doesn't know if one will want/need "advanced"
features until one tries them or until one moves to new areas of
I'd agree that things like "ditch lights", "Mars lights" and flashers
are all of little use on a pre-grouping shunting loco.
They're all written in German, or Chinese or mock-English!
My wife got annoyed when I set up the TV she had tried for hours to set
up to watch Coronation Street.
"I read the instructions and couldn't make any sense of them, how come
you did it?"
"Easy, you just have to pretend they are in English when you read them -
that and already know how to do it".
How about when you have a pre-grouping shunting loco and the salesman tries
to sell you something that has things like "ditch lights", "Mars lights" and
Not all suprisingly enough, but even those that do can have a helpful
diagram - says he having assembled a variety of lego things.
What can be said its like you should never let a lady open a carriage door,
it takes them far too long.
Well, when I got the decoder home I would find (in all probability) that
the flash rates etc are reprogramable so I could create a nice
flickering firebox door opening and still have two switchable outputs
that can be used when I decide to make an engine driver who waves to the
kids by the layout and the fireman who shovels another load of coal into
the far corner of the lit firebox!
See, I didn't even know I was going to model those features when I
I had one diagram that had the wire colours listed incorrectly but drawn
So every time you go into your local model shop you buy every electric,
diesel and steam loco, from all periods and all regions because when you get
home you suddenly decide you wish to model everything, everywhere ....
Also you have an articulated lorry in your garage that you use when you nip
down to the shops and ....
In case you are interested, I know of a wonderful old bridge over the river
thames that woud look very nice in your garden.
That includes me! What on earth is a packet structure, and for that matter
should I need to know, and more to the point should somone need to know who
is starting out in this hobby?
Yep am with you there, so who can test them - got any in your shop John ?
As far as I understand it we want to know if :-
a) tcs decoder set to 2 digit address (CV1) in range 1-59 by another system
can be read/reset using a select unit.
b) tcs decoder set to factory defaults can be programmed with the Select
I think Chris needs to backtrack on that one esp as this is a general group
not a DCC specific one for those who really want to debate the fine details.
Perhaps the debate on if a particular system is fullly NMRA compliant is not
a useful one. Of more interest is if a particular system does everything
claimed for it. Better still does it do everything a purchaser wants taking
into account the price vs features - wow the Hornby systems are tops on that
Surely, If manufacturers do not conform to a national or better still
an international standard and provide concise user instructions then
the customers should vote with their wallets.
Speaking as a control engineer of long experience, it is not necessary
to enter the "black box" and anything which is sold as a tool to a
project should be user friendly and not require a Ph.D in button
pressing or a facility in gobidigook speak.
That which I need to know to design, is in no way related to the
knowlege required by the end user. I often get the impression that
there is a group of "modellers" who merely wish to impress us with
their savoir malin.
I'm not quite sure I agree Simon. In theory if a product is fully NMRA
compliant then one can say with a fair degree of confidence that product A
from manufacturer B will work with product C from manufacturer D.
As an example, I was able to purchase an ESU Mobile (wireless) controller
with every confidence that it would work perfectly satisfactorily with my
(very basic) Lenz Compact command centre simply by pluggin one into the
other, and without any reprogramming.
Can one say the same with the new Hornby DCC range?
That to me is the real issue.
"Peter Abraham" wrote
Absolutely, but the reality some of the larger manufacturers work on the
basis that their name alone will sell the product, and the fact that it may
not be fully compatible with industry standards simply means that the
customer is locked into that product range.
It's important that people are informed when this becomes an issue, because
that 'locking in' can restrict their opportunities of taking full advantage
of all the features which DCC can offer.
No, you don't need to know exactly what "packets" are, but as in all
things technical, it helps if you have reasonably accurate mental image
of what's going on. In this case, a bit of technical knowledge helps you
understand what "NMRA compliant" means, for example. That could save you
So here's a technical explanation.
All data used by computers are formatted according to strict rules. For
example, every JPEG image file has a header that contains certain
information in a strict order. This enables a the image viewer program
to use the correct procedure for converting the data in the image file
into data that can be used by the video card that displays the image on
your computer's screen. Note that these image files are "platform
neutral" -- that is, they will work on any computer, regardless of
hardware or operating system, as long as the image viewer program knows
how to decode the data. DVD players too can display them on your TV, if
they have JPEG image decoder software built in.
A DCC decoder is a small computer. The data that it decodes comes in
small chunks called "packets." NMRA realised early one that if the
format of these packets were standardised, then manufacturers were free
to make any hardware they wanted to make. So NMRA specified the data
packet format. It also recommended colour codes for the wires used to
hook up the decoder to the locomotive. This recommendation has become a
de facto standard. (NMRA == National Model Railroad Association, founded
and headquartered in the USA, and an entirely volunteer _consumer_
organisation, not an industry one.)
Any hardware that can handle NMRA standard packets is NMRA compliant.
Any hardware wired with the NMRA colour coded wires will work with any
other hardware so wired. There are variations in the add-on function
available with different hardware offered by different manufacturers.
These variations determine what you can do with any given loco -
hardware combination, but all such combinations will control the
locomotive's speed and direction.
The last couple of years, some manufacturers have made hardware that
does not comply with NMRA standards or recommended practices. IMO you
should avoid such products. The NMRA standard is more than adequate to
enable a host of cool hardware. For example, a fully radio-controlled
DCC system with an on-board rechargeable battery is feasible. The radio
would transmit the control signals. The batteries would supply
uninterrupted decoder power. The rails would supply power for the
locomotive's motor and for keeping the decoder battery charged. Existing
hardware, available from Radio Shack et al, can be used to build such a
Just for the record: in case no one has yet proposed or patented this
obvious concept, I hereby claim originator's rights. If some
patent-jumper wants to make a fuss, this post is proof of "prior art". Hah!
This is very nice for the electronically literate but! I have been
acutely aware of how quickly people can curl up at the edges when
faced with this kind of explanation. A properly presented and marketed
product should need none of this. People want to play trains and DCC
was an attempt to remove the difficulties involved in the analogue
control of a sophisticated layout. This very discussion should
convince the most ardent DCCite that somewhere along the line this
objective has been lost.