Author Topic: MERG and the "CBUS"  (Read 6180 times)

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Online John Candy

MERG and the "CBUS"
« on: Sep 29 2014 11:35 »
MERG and the "CBUS"

Have been dreading the thought of wrestling with miles of cabling to signal the layout and how to interlock electrical and pneumatically-powered points and signals.

One big problem (ignoring the sheer quantity of wiring) was how to integrate three signal box positions which could be easily unplugged and removed when not in use .... without a mass of connectors and loose wiring which could potentially result in difficult-to trace breaks.

Ted Sadler has, on several occasions, suggested DCC as the solution and related how groups of MREG members attend Cliff's GTG, with the sole purpose of experimenting with electronic control.

I have never used DCC but assume it to be basically MUX/DEMUX as applied in computer networking.
This has the advantage of requiring just two wires to carry the signal to the demux unit fed from the two-wire BUS.

Well, today I have joined MERG and hope that their CBUS system will be the answer to my problem ..... although electronics and English weather are not an ideal combination!

One of the ideas being put forward by MERG is the use of "Raspberry Pi" micro-computers to run the CBUS....not sure I want to go that far.

Anyone have "thoughts" or suggestions?

John.
« Last Edit: Sep 29 2014 18:03 by John Candy »
My fellow Members, ask not what your Society can do for you, ask what you can do for your Society.

Offline hornbeam

Re: MERG and the "CBUS"
« Reply #1 on: Sep 29 2014 12:19 »
I did have a layout for a time using DCC control for trains and DCC control for points all from LGB, but having gone completely gauge 3 I've decided to go to DC only. Reason being I will only need 12 switches for the main station area split into two sections, 8 for the junction station and 4 for the branch terminus. I've decided to have signals to on the main loop will have the ability to be controlled by the train- reed switch control and a magnet fitted to the engines so it can run hands free. It might mean having more toylike LGB signals but better than no signals or even signals that stay at danger as attain passes through.

Even this will involve a lot of wiring so totally agree with your method for your layout.

My area of concern is trying to use LGB motors with cliff barker points- not sure it can be done.

Imagine I've answered no questions John, but thought I'd share my method of control.



« Last Edit: Sep 29 2014 18:10 by John Candy »

Offline 454

Re: MERG and the "CBUS"
« Reply #2 on: Sep 29 2014 12:48 »
John,

My experience goes back to the 1980's when I created a terminus to fiddle yard N gauge continental layout & had full point signal interlocking with mimic graphic diagram of signal & point status & block occupation on an old portable Sony B&W telly. The method I used was Hornby Zero 1 for the points & a microcomputer Z80 & 8085 based made by me with opto isolated input output ports driving small reed type relays & for inputs sensing switched on points to determine direction. But it still took a lot of wiring including butchering the side of the Zero 1 Master unit to patch the keyboard keys to the input ports on a ribbon cable. The whole interlock was burnt into a 4K EPROM with machine code. It worked like a dream. But even with the Zero 1 not using the track control facility with 2 twisted wires there was an abundance of other wires for other circuits & even for a small layout 12 feet long by 1 foot wide it took an age to accomplish & fathom out. Not exactly what you would desire.

Then I went to sleep electronically for a decade or longer after which LGB produced MTS/MZS which although costly produced a system which could be programmed from a manual which is 3 inches thick. Genuinely has limited 2 wire capability. So after amusing oneself with the basics & blowing out a loco chip when loco parked inadvertently on a point frog I decided that stumps would be drawn & live with simplicity. Then LGB turned belly up & Massoth took over the DCC side of things, this is where I went back to sleep again & have not awakened yet suffice to dole out this warning.

So after all that it is non-powered track for me, radio controlled locos & hand operated points.
Sorry I cannot be more positive John but you have a mountain to climb in terms of complexity & I wish you every success, will enjoy the outcome with much pleasure when you hold a GTG & look forward to admiring the result immensely.

Dave
454
« Last Edit: Sep 29 2014 18:11 by John Candy »

Offline IanT

Re: MERG and the "CBUS"
« Reply #3 on: Sep 29 2014 14:18 »
Hi John,

I've been a member of MERG for a little while and the CBUS system is quite interesting. It is based on what is effectively a local area network (LAN) but one basically designed by the automotive industry for cars! This means that there is a lot of hardware and software around that supports CAN (the technology behind CBUS).

My understanding is that there two 'forms' of CBUS - one where the 'components' are 'pre-set' and another which enables everything to be configured on the fly. I'd think the simpler system would probably suit you and all the hardware and system software required is available from MERG (and the 'kits' are reasonably priced too). In theory CAN is good for half a kilometre, so it should be fine for your purposes.

You should receive a CD with past MERG journals on it - and all the key information for their various systems (they have a few - CBUS, DCC etc).

However, if I was implementing a signalling control system for G3 - CBUS is certainly the system I'd choose at this time.

Regard,

IanT   
« Last Edit: Sep 29 2014 18:12 by John Candy »
Nothing's ever Easy - At least the first time around.

Online John Candy

Re: MERG and the "CBUS"
« Reply #4 on: Sep 29 2014 18:53 »
Thanks to you all for the replies........am pleased that nobody has said I am "stark staring bonkers"!!!

Glad to know that Ian T is thinking along same lines ..... I may be asking for suggestions with some aspects!

Last time I tried anything like this was on an indoor layout in the 1970's, using 30 relays (piggy-backed) to control a quadruple track junction, with four aspect colour light signals and correct automatic "sequencing" and "fail safe". The mass of wiring was horrendous .... but it did work, although the reliability of the relays was a maintenance problem.
I remember drawing copious "flow charts" and logic diagrams to work out the wiring for all the permutations of the track settings and signals (which included route indicators).

Until my MERG "welcome pack" arrives, there is not much I can do to further the proposals.

Regards,
John.
My fellow Members, ask not what your Society can do for you, ask what you can do for your Society.

Offline Traininvain

Re: MERG and the "CBUS"
« Reply #5 on: Sep 29 2014 19:37 »
I spoke with MERG on a couple of occasions about a control system for colour light signals that was suited to larger scales and out of doors and CBUS was the main component. I was going to buy enough gear at Warley last year to do some tests but they didn't have it with them. I'll have to dig my notes out but the plan was to set up a block signalling system suitable for 3 aspect signalling - green then red then yellow then back to green in sequence for each signal as the train progressed through the blocks. The key thing appeared to be a train detector and the best bet seemed to be some sort of infra-red beam system or similar that the train would break as it passed through and so cause the signal to change aspect. Must try and find some time as the prototype colour light signal is gathering dust awaiting assembly.

Ian

Offline Gavin_B

Re: MERG and the "CBUS"
« Reply #6 on: Sep 29 2014 20:20 »
One of the things that intrests me with gauge3 is the amount of electronics that can be used.   Am experimenting with an arduino micro computer to control a motor via bluetooth with a mobile phone.   Also used the same micro computer to control a servo to raise a signal to danger for a set period of time after a train has passed.

Offline 454

Re: MERG and the "CBUS"
« Reply #7 on: Sep 30 2014 07:53 »
My feeling about state of art electronic systems & model railway applications is that it benefits the group layout or the club layout when an abundance of skilful talent is available to contribute. The sum total of man hours for everything involved with a model railway is immense after consideration of dreaming, planning, acquisition, building the models, making & laying of track etc etc etc…..

The number of man-hours to just get up to speed with a new "micro" is enough to put me off now. Then one's time is rationed to a proportion of the remaining time available to achieve the end result.

So for a one man band this is a tall order unless there are abundant resources to draw from.

The availability of off the shelf DCC with programming capability gives one a step up instantly but at what cost?

As modellers we have to get the balance right between making models, getting them to operate in a realistic manner & then when all is complete having all trains passing signals at danger & never stopping in stations & failing mid section. So any attempt to bring us into a state where realistic operation is the final goal, I welcome.

Sadly this is one reason why my garden railway consists of a simple 24 feet diameter circle.

I have been considering installing one signal just for appearances sake & make it a bit like Gavin_B described which is a good way of keeping things simple. It is essential it does not detract from the relaxation of watching trains go by.

Good luck with the project

Dave
454

Offline IanT

Re: MERG and the "CBUS"
« Reply #8 on: Sep 30 2014 11:27 »
As someone who has (far, far) too many "things on the go" myself - I pretty much generally agree with you Dave on how much an individual can (should?) take on and still hope to actually finish.

Very large projects are generally best left to groups, mainly because of the advantages of shared labour but also (I suspect) because individuals can then 'focus' on just a few things (rather than many). However, John seems to be demonstrating that given sufficient determination, an individual can achieve very remarkable results.

I have what I consider to be quite a wide range of interests but many of them fall more into the "armchair" category (e.g. mainly reading and 'imagining') than being activities I can actively implement. Some areas I do pursue a little further (let's call it 'playing' rather than 'experimenting'). For instance I have had a long time interest in micro's (dating back to my Z80 Nascom II system).  Gavin has mentioned Arduino and I've had a Uno for some time. Arduino is a very interesting concept (and not expensive) and can be programmed directly from a PC. I've also dabbled with the Forth language for many years (not exactly a mainstream language) and can only explain this as being a better mental activity than doing Sudoku. Having said that, I was really pleased recently to get my Arduino 'chatting' to my PC's Forth system via USB - so I can now connect my laptop to the real world in a simple way.

But what does all this Arduino, Forth & CBUS stuff 'play' mean in the real (G3) world? Well nothing very much at all so far. But one day I may surprise (myself mainly) and come up with an on-board control system for live steam engines or a simpler (semi-electronic) gear hobbing unit. Maybe one day there will sufficient interest in 'modules' (here in UK that is) that there will even be a need for a flexible system to control train movement across larger spaces?  Who knows - I don't smoke - so haven't got a pipe but I can still dream a little.

Back to John's 'real world', CBUS is well supported and John doesn't have to design and build everything himself. There are many others (often with expert qualifications) contributing to it's development. With this open source model, I think CBUS has far more going for it than a proprietary system which must be limited by commercial constraints. The open source nature of CBUS is also a factor in keeping costs down. People are already hooking up Android phones to CBUS systems - so Gavin, one day you might be able to control your engines and request a signal/turnout change - all from your phone - who knows what will be possible?

Anyway - the weather looks good so I have work to get done in the garden before the winter sets in. Back to Dave's real world then!

 :)

Regards,

IanT

 
Nothing's ever Easy - At least the first time around.

Offline MikeWilliams

Re: MERG and the "CBUS"
« Reply #9 on: Sep 30 2014 16:20 »
I don't like electronics.  I know little about them and want to know even less.  But, last Monday I was invited to a 7mm model railway which is all DCC and most of the 50+ locos had sound cards too.  All were professionally built to the very best standards.

First thing I noticed was that when the mains power was turned on a loco started moving, straight through the catch points and derailed.  The owner frantically picked up three controllers before finding the right one, then had to punch in which engine it was, and then control the power.  When operating fully the effect was very good indeed, but for me its all far too complicated and uncontrollable.

I'll stick with batteries and maybe not even radio control.

Luddite Mike

Offline IanT

Re: MERG and the "CBUS"
« Reply #10 on: Sep 30 2014 17:01 »
I wasn't suggesting control of the locos via the CBUS Mike - just the signalling and turnouts.

Generally, I think (in G3) control of engines is very likely to remain on a "one-driver, one engine" at a time basis - but perhaps on some G3 railways in the future - you won't be allowed to climb out the cab and throw your own points (so to speak) - you'll have to await signals!  :-)

My comments about 'Arduinos' & steam locos was not just about ways of 'driving' the engines but also other functions (such as sensing water levels & automatic bypass control for instance). We have very little 2-rail in G3 so apart from 'free running' , R/C control is pretty much the standard for us - but there are other alternatives around (infra-red & Bluetooth for instance) that may have advantages. And in the same way I don't know too much about the inners of the latest R/C kit these days, I don't think anyone will have to know too much about how any new alternatives work - it will all mostly be "black box" stuff. You'll plug it in and just use it.

Exactly what those 'black boxes' will do remains to be seen - but I'm sure it will be something tempting!  :-)

Regards,

IanT 
Nothing's ever Easy - At least the first time around.

Online John Candy

Re: MERG and the "CBUS"
« Reply #11 on: Sep 30 2014 19:09 »
Quote
you won't be allowed to climb out the cab and throw your own points (so to speak) - you'll have to await signals!  :-)

That's exactly what I am aiming for, particularly in view of my complex track arrangement, which could result in serious and damaging collisions if left as a "free for all"!

The only involvement of power through tracks will be "track circuiting" to indicate line occupancy.....certainly no intention of using CBUS (or DCC) to control locos.

Regards,
John.
My fellow Members, ask not what your Society can do for you, ask what you can do for your Society.

Offline IanT

Re: MERG and the "CBUS"
« Reply #12 on: Oct 01 2014 22:25 »
By the way MERG has quite a lot of technical information available to non-members on their website and a pretty detailed overview of CBUS is available here:

http://www.merg.org.uk/merg_resources/cbus.php

Regards,

IanT
Nothing's ever Easy - At least the first time around.

Online John Candy

Re: MERG and the "CBUS"
« Reply #13 on: Mar 06 2016 20:49 »
This topic has been "dead" for a while now but it seems a good time to revive it!

There has been discussion within the Monkton Priors team about signal/turnout control and interlocking and Ian T has volunteered to do further research into possibility of a CBUS solution.

I have been discussing turnouts with Ken Cottle (he has volunteered to construct and pay for the six turnouts required for Monkton Priors station) and mentioned that the turnout blades should be pivoted (not biased or "sprung" in any way, as would be the case with Cliff's standard tie-bar arrangement) since we will probably use servo motors to power them. He said that he uses servo motors himself and has a PCB based digital control which sets the range of movement of the switch blades.

Has anyone here actually "dived in" and used CBUS since we last discussed this?

I have here a "Minx MicroDrive" package which consists of a pair of (postage stamp sized) actuators and a sophisticated digital controller and warning system. When the weather improves i will venture into the garden and install it...the big question is, how will it stand up to the damp?

John.


My fellow Members, ask not what your Society can do for you, ask what you can do for your Society.

Offline wolfstone

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Re: MERG and the "CBUS"
« Reply #14 on: Mar 07 2016 08:26 »
I am wrestling with the same problem for my layout. I too was thinking servo for point and may be signal control.
Whilst at the recent Scottish model rail exhibition I spoke to Fraser Black of 'Sig-na Track', he had a small unit that controlled the movement of the servo and could be DCC or CBUS. I  use Crest radio control for my loco's and these have a facility for controlling 5 servo's via a RC unit.
Tim