Your opinion? - DC or DCC (poll)

Started by petercharlesfagg, October 17, 2013, 06:39:53 PM

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EtchedPixels

Quote from: Zwilnik on October 21, 2013, 11:39:46 AM
Yes, that's still DCC though so still requires 1980s technology in the engines and the

Actually the bits in the locos are very modern technology. You couldn't do it with 80's technology

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various competing standards of DCC to maintain.

DCC is a single set of back compatible standards. You can take an early DCC decoder and use it today (although it would probably be several times too big for an N scale loco). There are multiple vendors who can't agree about their own extra add on controller busses but that is true of DC as well where there are 3 competing standards for point motors even.

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I'm thinking more along the lines of a new standard that uses current technology to put BT/Wifi transceivers in the engines rather than control via the power source. That way you only use the track for power and don't need special controllers or adaptors.

Wifi (looking over all the various usual 802.11 standards and different incompatible stuff) is very hard to do well and cheaply in a very small space. Bluetooth has some rather tricky protocol limitations. Neither work well with a large number of active nodes or are particularly good at guaranteed delivery within a short time (ie sending 'stop' before the buffers)

Radio is easy in O gauge and a lot of O particularly outdoors seems to favour battery and radio control.

For the loco they are both the wrong technology. Radio may well eventually be a very useful model technology but I don't think you'd want current wifi technology. Zigbee or similar lower power 'internet of things' stuff perhaps. Zigbee was pretty much designed for this sort of usage - lots of small low power devices, relatively low communication rates, and extreme power efficiency. Zigbee itself has stupid licensing problems but there is a project to simply fix that by throwing out all the higher levels of the Zigbee technology and using internet stuff on their hardware.

Alan
"Knowledge has no value or use for the solitary owner: to be enjoyed it must be communicated" -- Charles Pratt, 1st Earl Camden

zwilnik

Quote from: red_death on October 21, 2013, 11:54:36 AM
Quote from: Zwilnik on October 21, 2013, 11:39:46 AM
Yes, that's still DCC though so still requires 1980s technology in the engines and the various competing standards of DCC to maintain. I'm thinking more along the lines of a new standard that uses current technology to put BT/Wifi transceivers in the engines rather than control via the power source. That way you only use the track for power and don't need special controllers or adaptors.

I'm not sure what you mean about competing standards of DCC - there aren't any when it comes to control, though there are when it comes accessories/feedback etc.

Personally I think there is sufficient critical mass in DCC that we aren't going to see a change to something different in the foreseeable future (by which point BT/Wifi will also be old tech!).

Cheers, Mike

Some chips seem to work better with some controllers etc. Not all chips work in all engines. No actual single standard that all the manufacturers have signed up to, just a general idea.

Bluetooth and WiFi are both evolving standards so will be around in some (still compatible) form for years to come whereas DCC still isn't default for all new locos, in some case it's still not even available as a "made for DCC" option.

It'll take a pretty radical manufacturer to come up with something new and push for a proper standard, but I don't see the model railway industry evolving much until something like this happens.

red_death

Quote from: Zwilnik on October 21, 2013, 02:05:56 PM
Some chips seem to work better with some controllers etc. Not all chips work in all engines. No actual single standard that all the manufacturers have signed up to, just a general idea.

Some of that is just incorrect - all chips work in all locos subject to space. What differs is how well a particular decoder controls that loco (generally the more expensive decoders provide better out of the box control), but that is also true of some DC controllers.

I'm not aware that there are issues with controllers and decoders - the NMRA standards are designed precisely to avoid that!

Quote from: Zwilnik on October 21, 2013, 02:05:56 PMBluetooth and WiFi are both evolving standards so will be around in some (still compatible) form for years to come whereas DCC still isn't default for all new locos, in some case it's still not even available as a "made for DCC" option.

That is hardly the fault of the NMRA DCC standards, that is a failure of manufacturers to design in some form of DCC ready provision.  Changing from DCC to BT/Wifi isn't going to change that!  BT/Wifi are only a communication method, not the whole solution.



zwilnik

Yup. I'm just saying that having a non-standard (in terms of major communications standards) system that transmits data through the track wiring to the engine and then ends up using another wireless coms system (some of which I've seen actually clash with the WiFi frequencies, which is very poor) is a bit of a primitive system to use when you could just design a standard of controller chips that have a proper communications standard (Bluetooth is good enough for the distances involved, but Wifi would be better for expandability, communications speed and general power).

With the chip on receiving power from the track (or alternatively the whole loco running off a rechargeable battery) and controlled directly via WiFi, you've got a much easier system to setup and control and potentially a much cheaper and compact one as BT/WiFi components are standardised and getting tinier and cheaper by the day.

EtchedPixels

DCC is not a "non-standard", its a set of NMRA standards as real as the standards for wheels, gauge and track

DCC was also very carefully designed. Power/signalling over the same two wire bus when the bus is arranged randomly including loops is an interesting problem space.

802.11 wifi and bluetooth don't have the needed properties for radio control of trains, in particular the real time delivery of packets to a large number of nodes. What in internet terms equates to an annoying lag moment in your 3D shoot em up in DCC terms equates to burying your new loco in the end of the bay platform.

There are reasons the O gauge folks don't use 802.11 but use other setups for the most part.


Controller to handset can go 802.11 wireless fairly easily (some issues around timing on a busy network) but loco control is a very different problem especially on a big layout.
"Knowledge has no value or use for the solitary owner: to be enjoyed it must be communicated" -- Charles Pratt, 1st Earl Camden

davecttr

Quote from: Zwilnik on October 21, 2013, 02:52:48 PM
Yup. I'm just saying that having a non-standard (in terms of major communications standards) system that transmits data through the track wiring to the engine and then ends up using another wireless coms system (some of which I've seen actually clash with the WiFi frequencies, which is very poor) is a bit of a primitive system to use when you could just design a standard of controller chips that have a proper communications standard (Bluetooth is good enough for the distances involved, but Wifi would be better for expandability, communications speed and general power).

With the chip on receiving power from the track (or alternatively the whole loco running off a rechargeable battery) and controlled directly via WiFi, you've got a much easier system to setup and control and potentially a much cheaper and compact one as BT/WiFi components are standardised and getting tinier and cheaper by the day.

Radio control for model trains has been around for a number of years but the last year has brought interesting developments. Basically the technology uses the 2.4 GHz band used by model planes, cars and ships.

for example i am just starting experiments with radio control and battery power for my N stuff. The 12 train controller costs £58 and the receiver chips, there are several varients, cost up to £32.  Add the batteries, if you can fit them in for N and you can run your trains on 'deadrail' with no track power, or on DC or DCC layouts with no modification. Just remembered, you can draw DC power from the track if you wish.

I would equate the radio technology with DCC in its early years. The basic stuff can be done including lights and apparently even sound. There is PWM for the motors to give good slow running. The controller I have ordered also includes 'inertia' for smooth acceleration and braking.

MikeDunn

Quote from: Big Dave on October 20, 2013, 12:47:02 PM
The best system is one that is available to you now and which has sufficient support available, and suits your pocket. Waiting for future innovations can rob you of enjoying the here and now, and none of us know what the future will be.
Hear, hear.

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