DCC Theoretical Question.

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Mountain
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DCC Theoretical Question.

Postby Mountain » Sat Apr 10, 2021 12:59 pm

Question.

There are radio control systems like Deltang and others that do not rely on track power, though they can actually be made to work with track powrr, but it defeats the object.

Is it possible in theory, to have a radio control interface that allows one to use a DCC controller to power trains via radio control that does not use track power, but the trains have onboard batteries?

In other words, one can use radio control through ones standard DCC controller. Would such an interface be possible. I know I am less likely to use it, but I was wondering if such technology exists or would be possible? Modern radio control systems do control sounds and lights etc and can fit in small locos. They have even fit them into N gauge... So I was thinking that maybe to have such technology may be the future? Independent trains under complete control that can recharge on small sections of "Clean track" where all other track can be realistically left to rust etc... (Visually. Real rusty track may be ok indoors but outdoors it would quickly end up being a brown stain on plastic sleepers with no rails left!)

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centenary
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Re: DCC Theoretical Question.

Postby centenary » Sat Apr 10, 2021 1:43 pm

I think there's a bit of a misconception about radio control here or maybe it's just terminology?

I fly electric 1:6th scale helis with RC but, it isnt RC that provides the motive power to the brushless motor for flight. Yes, the motive power is controlled by RC via an electronic speed controller (esc) but the motive power itself is provided by a separate lipo battery pack.

Obviously, the lipo battery only provides power for as long as it has sufficient charge and, one should never run a lipo down to the voltage it can no longer provide enough power to give motion. Do that repeatedly and your lipo battery will be kaput pretty quickly.

You can use steam or another fuel as an alternative power source for trains but you still have the same problem, eventually the power source runs out and needs refuelling. Power to the rails is the way to go imho.

Im not aware of any DCC to RC control interface. Technically, one could be designed but it just adds another layer of complexity and potential failure especially when you consider DCC wifi control is readily available. Just my opinion though.

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Re: DCC Theoretical Question.

Postby Mountain » Sat Apr 10, 2021 3:10 pm

The idea is to run the locomotive from onboard batteries via radio control. Yes, there have been and are DCC systems that have wireless control from the handset to the control system, but this is not where I see the advantage of a control system. I see it in the ability to run on track that has a complete rust coating on the rails for added realism. There is DCC "Stay alive" but while it is in stay alive mode, the locomotive is not under control. It merely carries on its last command, which is fine for a power interuption to the rails, but is not what I am looking at as a concept.
Yes, there are full radio control handsets which to be honest are the best option, but I was wondering if it were a possibility to use a DCC controller interface, and I am only asking out of curiosity because I have never heard of such a device and I was wondering if one has been built or if it is possible in theory. I am not saying that I would buy such a device, as to me those radio control handsets specific for locomotive control are the best option. It was just out of curiosity to learn what was possible or not that I asked the question.

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centenary
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Re: DCC Theoretical Question.

Postby centenary » Sun Apr 11, 2021 2:02 pm

Mountain wrote:The idea is to run the locomotive from onboard batteries via radio control. Yes, there have been and are DCC systems that have wireless control from the handset to the control system, but this is not where I see the advantage of a control system. I see it in the ability to run on track that has a complete rust coating on the rails for added realism. There is DCC "Stay alive" but while it is in stay alive mode, the locomotive is not under control. It merely carries on its last command, which is fine for a power interuption to the rails, but is not what I am looking at as a concept.
Yes, there are full radio control handsets which to be honest are the best option, but I was wondering if it were a possibility to use a DCC controller interface, and I am only asking out of curiosity because I have never heard of such a device and I was wondering if one has been built or if it is possible in theory. I am not saying that I would buy such a device, as to me those radio control handsets specific for locomotive control are the best option. It was just out of curiosity to learn what was possible or not that I asked the question.


Yes, I appreciate all that and yes, theoretically, it should be possible to use DCC to control RC. It's just a question of one protocol talking to another, a suitable interface and someone designing, testing and building it.

But there are also other considerations that muddy the waters. Most RC people now use 2.4ghz and something like DMSS transmission protocol as this now gives faster and superior interference rejection communication between transmitter and receiver. You could use good old 27mhz or 40mhz FM (presuming you're UK based) but these are more susceptible to other electronic interference from motors or other outside sources plus have longer aerials to hide. Using steam, you'd have to make sure your receiver is away from excess heat and possible steam.

I guess the point Im getting at is, it, DCC to RC, is just an added layer of complexity and potential point of failure not to mention additional cost.

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Re: DCC Theoretical Question.

Postby Bigmet » Sun Apr 11, 2021 3:06 pm

centenary wrote:...But there are also other considerations that muddy the waters.

Now I have a question, about the greatest 'muddying of the waters' when it comes to RC for train control.

Preamble.
RC discussions start with an assumption of the imperative need to prevent signal corruption/loss to free moving vehicles. This simply does not apply to rail guided vehicles, which will stay on the rails quite safely until the signal is received again.

The DCC scheme of frequent retransmission of addressed control packets to the decoders on the layout handles signal loss at the noisy rail to wheel interface by design. There's no reason why a scheme on the same principle should not be used for radio control of rail vehicles.

What we don't need for model railway RC is 'binding' of transmitter and receivers. That's a free vehicle control requirement, not applicable to rail guided vehicles which cannot fall out of the sky or go out of transmitter range.

Question.
Is there a hobby level RC system available which can effectively simultaneously address a large proportion of any of a thousand receiver addresses from a single RC handset, which uses a rapid repeat of the addressed control packets to ensure sufficiently robust communication, and doesn't bother with 'binding''?

That's the RC product capability baseline requirement to replace DCC, because this is what we already enjoy.

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Re: DCC Theoretical Question.

Postby Mountain » Sun Apr 11, 2021 4:21 pm

Bigmet. Have you seen these?

http://rctrains.co.uk/Transmitters.htm

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Re: DCC Theoretical Question.

Postby Flashbang » Sun Apr 11, 2021 6:00 pm

Biggest issue, is as always, Battery size needed to run a N or OO/HO loco for any reasonable time and also power to any Receiver too and then fit the lot inside the loco plus the RC receiver. You also need to either open the locos body and remove the battery for re charging or have some charging circuity inside and a connection socket would also be needed on the loco to allow onboard recharging.

IMO It is all hypercritical in smaller scales at this time and really not worth the conversation. Battery size, RC Rx or Blue Tooth receiver device and a battery Charger device will just not fit in a smaller scale loco. Move up to O or larger and perhaps you may find room?
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Re: DCC Theoretical Question.

Postby Bigmet » Sun Apr 11, 2021 7:14 pm

Mountain wrote:Bigmet. Have you seen these? http://rctrains.co.uk/Transmitters.htm

Yes thanks. That's an example of the 'dinosaur' RC control that's a backward step in the context of available model railway control systems.

Why would I want a system that restricts me to just 12 locos on a handset? I have a DCC control system that allows instant control of over 250 locos; so besides the near 90 on my layout, I can run any visiting loco 'just like that'. With multiple handsets it allows more operators than would comfortably fit in the layout room to operate any loco (3 handsets are sufficient for my purposes). There's tech available that could exceed this using RC, but I don't see any such on the market for model railway control.

To make the breakthrough, RC model railway control has to beat the proven and available control system benchmarks; and at present all the commercial offerings I have seen fall waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaay short.

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Re: DCC Theoretical Question.

Postby BananaRepublic » Sun Apr 11, 2021 10:29 pm

Mountain wrote:Question.
....Is it possible in theory, to have a radio control interface that allows one to use a DCC controller to power trains via radio control that does not use track power, but the trains have onboard batteries?

In other words, one can use radio control through ones standard DCC controller.
Would such an interface be possible....
........I was wondering if such technology exists or would be possible?


centenary"....I'm not aware of any DCC to RC control interface......[/quote]

[quote="Mountain wrote:
.........I have never heard of such a device and I was wondering if one has been built or if it is possible in theory. ....



Hi Mountain.
What you are asking about has been commercially available for 20 years or more in various guises.
DCC commands delivered wirelessly, direct to the loco and received by onboard electronics that feed regular DCC commands to a decoder.
Motive power provided by onboard batteries.

The company who have been providing this kit the longest, is US company CVP, makers of an American DCC system called Easy-DCC.
Their AirWire systems have been available in various versions for a long time, but these are only sold in North America, use radio bands not approved for use in the UK or Europe...and are aimed at larger scale models.

US DCC manufacturer NCE, used to sell a wireless DCC system called G-Wire, which used wireless handsets similar to their own ProCab and PowerCab handsets.
This again was aimed at larger scale outdoor layouts.
I believe that G-Wire is also compatible with the CVP AirWire system
NCE stopped selling G-Wire about 10 years ago or so.


Another way to obtain "wireless" or "radio" DCC, is a product made by Tam Valley Depot, who are best known for their range of "Frog Juicers".
Tam Valley's DRS-1 system. (Dead Rail System), is rather ingenious.
It isn't a control system itself, but an add-on to ANY DCC system, that provides wireless transmission of DCC signals, direct to a receiver in your loco.
DRS-1 consists of a transmitter module that attaches to your DCC system's track output and an onboard receiver board that goes in your loco.
There are no configuration settings or anything like that and the only limitations on how many locos can be controlled at once, are the same as for the host DCC system you are using.

The transmitter unit is simply connected to the DCC track output of any DCC system.
This module wirelessly broadcasts all the DCC commands being output from your DCC system.

The receivers in the locos are connected to the onboard batteries and feed the combined battery power and received DCC signals, to any regular DCC loco decoder .
The DCC decoder can be any sound or non-sound of your choosing.

Tam Valley make a European (inc. UK) legal version of this system.
The only downside, apart from the extra cost per loco, is having space to fit the onboard receiver and battery, so it would be quite difficult to fit this in a 00 or H0 scale loco, unless the additional kit is located in a tender, or attached wagon or carriage.


z
Last edited by BananaRepublic on Sun Apr 11, 2021 11:50 pm, edited 3 times in total.

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Re: DCC Theoretical Question.

Postby BananaRepublic » Sun Apr 11, 2021 11:00 pm

Just to show what's available commercially, another wireless digital control system, is American company, Ring Engineering's "RailPro" system.

https://www.ringengineering.com/RailPro.htm

Only available in the USA and not approved for use in Europe (inc. UK).
It is an advanced, modern digital control system, a few steps on in technology terms from the nearly 30 year old tech of DCC.
Unfortunately it's a proprietary system, but it has been updated in recent times to provide compatibility with DCC decoders.
However, if you were designing DCC from scratch today, I'm sure it would look something like

RailPro separates motive power from the control signals.
As originally released, motive power is provided by a constant fixed voltage track supply, which can be DC, DCC or even AC (as in Marklin etc).
More recently, the option to use on-board battery power has been made possible, as an alternative.
While motive power is sent over the track, or from on-board batteries, the control signals are transmitted over a modern, high speed digital wireless network, which is 2-way and multi-way, with handsets, locos, accessory decoders and other trackside modules, power supplies etc, all communicating with each other over a wireless Mesh network.

There is no command station to speak of as this function is handled in software in each handset, or on the optional computer software control package.

Control and programming of decoders is made very simple, through an intuitive control interface.
Simple programming of parameters and performance without complicated CV's, plus there’s an automatic speed matching facility for all locos placed in a consist.

The automatic speed matching requires no user intervention, no programming or fiddling with speed tables and speed curves.
The loco decoders in a consist, talk to each other and adjust their loco's performance automatically, according to each loco’s engine load, dynamically in real time. That's streets ahead of DCC.

Similarly, all decoder parameters (CV’s in DCC speak) can be adjusted “on the fly” in real time, as the loco operates.
No need to go to to a programming mode, or put the loco on a programming track.
This includes loco performance, lighting and sound effects etc.

RailPro decoders come in sound and non-sound versions.
Sound projects and files can be downloaded over the internet and uploaded on to the respective decoder, using the regular control handset.
That way updates can be made on the fly, without having to have a decoder "reblown".

There are more features, but also a couple of downsides, most notably the proprietary nature of the system and lack of DCC type universal standards, so Ring is the only manufacturer of all system components.
However, continuing efforts have made this system more compatible and interchangeable with regular DCC.

z

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Re: DCC Theoretical Question.

Postby Bufferstop » Mon Apr 12, 2021 12:07 am

Due to its open source nature DCC has been able to add new ideas over it's lifetime. The most common problem still seems to be the dead spot, and it's the loss of traction current which seems to be the problem, as when control signals don't come through it's designed to "go on doing what the last instruction said" and if you have traction you should get control back soon. I think we should keep our fingers crossed and watch keenly for development in supercapacitors and miniature batteries.
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Re: DCC Theoretical Question.

Postby centenary » Mon Apr 12, 2021 1:06 am

Bigmet wrote:
centenary wrote:...But there are also other considerations that muddy the waters.

Now I have a question, about the greatest 'muddying of the waters' when it comes to RC for train control.

Preamble.
RC discussions start with an assumption of the imperative need to prevent signal corruption/loss to free moving vehicles. This simply does not apply to rail guided vehicles, which will stay on the rails quite safely until the signal is received again.


Er yes it does! The loco may be guided by the rails but I think you're overlooking signal interference regarding speed control, stop \ start, direction, lighting and sound control and any potential other functions.

In the old days of 27mhz and even 35mhz, we had to limit the number of aircraft flown at the same time due to the possibility of cross channel interference. This interference has been virtually eliminated with 2.4ghz transmissions protocols that 'frequency hop' pretty instantaneously. There's more electronic wizardary to it than I could explain and effectively, the only interference now is if someone deliberately transmits a more powerful signal.

The DCC scheme of frequent retransmission of addressed control packets to the decoders on the layout handles signal loss at the noisy rail to wheel interface by design. There's no reason why a scheme on the same principle should not be used for radio control of rail vehicles.


Yes, modern RC is similar. You're constantly 'transmitting' a signal to you receiver even if you arent changing the command else the servos would return to neutral or some other failsafe setting.

I think you're forgetting the DCC packets of information have to be converted into radio signals so the signal may be clean when it's sent by DCC but could become noisey when converted to 2.4ghz or more likely 40mhz and 27mhz FM.

What we don't need for model railway RC is 'binding' of transmitter and receivers. That's a free vehicle control requirement, not applicable to rail guided vehicles which cannot fall out of the sky or go out of transmitter range.


If you're using 2.4ghz RC transmission protocol, you will need to bind the transmitter to the receiver. Some RC systems can do this seamlessly and is called 'easy bind.' Older less reliable RC such as 27mhz and 40mhz doesnt require binding but does require matched transmitter and receiver frequency via changable crystals. It's not a question of going out of range, it is how susceptable the RC is to interference. RC cars and boats operate over a similar range as a garden layout and you can still get cross channel interference.

Question.
Is there a hobby level RC system available which can effectively simultaneously address a large proportion of any of a thousand receiver addresses from a single RC handset, which uses a rapid repeat of the addressed control packets to ensure sufficiently robust communication, and doesn't bother with 'binding''?


As mentioned above, 2.4ghz does need transmitter to receiver binding. Protocols such as 'x bus' via DMSS can handle lots of 'information' to many servos on a single channel. While you wouldnt want numerous servos on a single channel to operate a loco, you could if you wished use x bus to send many different addresses. This is effectively what x bus does, it gives each servo on the same channel separate instructions when to move, how fast, how far for example.Traditional 27mhz and 40mhz FM (and AM) is far more limited.

That's the RC product capability baseline requirement to replace DCC, because this is what we already enjoy.


To be honest, there isnt a lot of difference as I see it between 2.4ghz DMSS RC and DCC as a control methodology. My transmitter and receiver combo has a 30 model memory. Not many people have 30 models and some systems can accommodate more.

Like loco addresses and cvs on DCC, each model memory has setting for each aircraft type, 14 separate control channels, range of movement on each channel, servo speed of each channel etc. The slight difference with DCC isall \ most of this info is held on the decoder in the loco rather than the handset.

As Ive said, if someone had the wherewithall, Im sure they could design a DCC \ RC interface. But I suspect the market for such would be relatively small.

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Re: DCC Theoretical Question.

Postby BananaRepublic » Mon Apr 12, 2021 8:50 am

The RC technology being described, that’s used in RC models is not suited to model railways and is already superseded by wireless digital that already exists for model railway use.
How about extreme robustness to signal interference, no binding of locos to controllers, full 2-way communication, multiple controllers in use (up to 40 at once), up to 960 locos operating at once with no degradation of system signal speed, a full range of features and functions that exceed those of DCC,
Loco programming in real time etc, etc.

Alternatively, you can add wireless transmission of DCC command to any make and model of DCC system.

All commercially available, off the shelf, today.

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Re: DCC Theoretical Question.

Postby Bigmet » Mon Apr 12, 2021 9:31 am

I am not fussed about the DCC signal structure being ported over to wireless. Forty years of intervening development since DCC got off the ground means there's room for progress there. 'Equivalent and preferably better functionality and performance all around' is the name of the game that I will be attracted to.

'Wireless' BTW doesn't 'add value' or compensate for shortcomings, it's just another signal transmission utility, nothing special. That's something that clouds the vision of those marketing wireless control systems - I don't care about 'how', just that the performance in my hands is at minimum equal, and preferably superior, to previously available control systems.
centenary wrote:...To be honest, there isn't a lot of difference as I see it between 2.4ghz DMSS RC and DCC as a control methodology. My transmitter and receiver combo has a 30 model memory. Not many people have 30 models and some systems can accommodate more.

That's heading in the right direction, but I believe those who are keen on railway modelling typically end up with many more than 30 locos, (they don't crash and burn y'see) and we want everything in the way of capability we have already from DCC. Please name any brands that currently have the greatest capability in your opinion.
BananaRepublic wrote:...All commercially available, off the shelf, today.

Names of brands marketing such 'everything DCC already offers in wireless systems ' please.

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Re: DCC Theoretical Question.

Postby BananaRepublic » Mon Apr 12, 2021 11:16 am

Bigmet wrote:
BananaRepublic wrote:...All commercially available, off the shelf, today.

Names of brands marketing such 'everything DCC already offers in wireless systems ' please.


Hi,
I have already mentioned some brands in my previous posts above.
In addition to those I've already mentioned, there are also direct wireless systems such as WifiTrax and BlueRail Trains.

The latter, BlueRail Trains is being relaunched in a mark 2 iteration, with DCC compatibility built-in.
They also have one of the DCC sound decoder manufacturers involved, who will soon be releasing DCC sound decoders with embedded Bluetooth modules on the "chip", to allow wireless DCC operation.
This is a digital control system that require no command station or the purchase of any controllers.
All that's needed is the onboard electronics and a power supply, either on-board battery or fixed voltage through the rails.
Everything else, inc. the control system, is software.

z
Last edited by BananaRepublic on Mon Apr 12, 2021 11:37 am, edited 3 times in total.


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