DCC Track Isolation Section Ready for Block Detection

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rgsmg53

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I am looking for help on planning electrical track isolation sections - background as follows:

I have been using the Piko Navigator DCC system for some years now and generally find it excellent. Until recently, any layout was constructed each time the grandchilren wanted something to do on a rainy day and the ability to be able to simply connect two wires whatever the track configuration at the time was a real benefit. Now, with the grandchildren getting older and becoming more computer-savvy, it's time for a permanent layout in the loft.

All track planning is complete as is a 'proof of concept' layout so it is now time to start laying permanent track. The strategy is to future-proof the track section design to allow simple DCC 2-wire operation to start with, adding mimic panel control (Megapoints System 2) and then to full computer control (JMRI or similar).

But I'm stuck already! My initial - and fundamental - questions are as follows:

1. Is it OK just to electrically isolate one rail (assuming I'm only using one DCC supply source)? Techincally, I can't see why not.
2. I cannot find any discussion / explanation why points and crossings should or should not be included as part of a block. Any advice gratefully received.
3. The layout is all single track continuous loops with bi-directional running (and will be signalled as such) so does this mean (for instance) that I will need additional isolated sections inside blocks and / or multiple occupancy detectors per block?
4. If I decided to use Automatic Braking Control (diode system) would this reduce the number of isolation sections within a block and has any one used it successfully with bi-directional running?

Sorry for such simple questions but I don't want to lay track until I have a better understanding. Is there a go-to explanation out there somewhere? I've been trawling the internet / you tube/ etc for weeks and there is a lot of authoritive but conflicting information out there. Even the absolutely excellent Megapoints vidoes haven't put my mind at rest.

Any help and advice most welcome.
 
rgsmg53 said:
Mods: Please move this post if there's a better section for it.

I am looking for help on planning electrical track isolation sections - background as follows:

I have been using the Piko Navigator DCC system for some years now and generally find it excellent. Until recently, any layout was constructed each time the grandchilren wanted something to do on a rainy day and the ability to be able to simply connect two wires whatever the track configuration at the time was a real benefit. Now, with the grandchildren getting older and becoming more computer-savvy, it's time for a permanent layout in the loft.

All track planning is complete as is a 'proof of concept' layout so it is now time to start laying permanent track. The strategy is to future-proof the track section design to allow simple DCC 2-wire operation to start with, adding mimic panel control (Megapoints System 2) and then to full computer control (JMRI or similar).

But I'm stuck already! My initial - and fundamental - questions are as follows:

1. Is it OK just to electrically isolate one rail (assuming I'm only using one DCC supply source)? Techincally, I can't see why not.
2. I cannot find any discussion / explanation why points and crossings should or should not be included as part of a block. Any advice gratefully received.
3. The layout is all single track continuous loops with bi-directional running (and will be signalled as such) so does this mean (for instance) that I will need additional isolated sections inside blocks and / or multiple occupancy detectors per block?
4. If I decided to use Automatic Braking Control (diode system) would this reduce the number of isolation sections within a block and has any one used it successfully with bi-directional running?

Sorry for such simple questions but I don't want to lay track until I have a better understanding. Is there a go-to explanation out there somewhere? I've been trawling the internet / you tube/ etc for weeks and there is a lot of authoritive but conflicting information out there. Even the absolutely excellent Megapoints vidoes haven't put my mind at rest.

Any help and advice most welcome.
Click to expand...
Cant help much with 1-3 but Diode reduction of power will not work in the way you require with DCC. Most DCC systems with automatic running options will allow auto slow down likely using some kind of sensor.

All of what you require would be possible on Analogue using LGB EPL system.
 
dunnyrail said:
Cant help much with 1-3 but Diode reduction of power will not work in the way you require with DCC. Most DCC systems with automatic running options will allow auto slow down likely using some kind of sensor.

All of what you require would be possible on Analogue using LGB EPL system.
Click to expand...
Thank you for your reply but I'm wondering if you misunderstood my question 4.

I already know that ABC braking works very well with DCC assuming one has decoders fitted which support it. There is plenty of evidence available and the demos I have seen are impressive. I use Zimo decoders which support the feature with the appropriate CVs enabled. My understanding is that ABC will NOT work with analogue as it relies on an asymmetric DCC signal (which is what the diode array provides) being sensed by the loco's decoder. My question was whether it was possible to set up ABC so it operated in both directions of travel.

Apologies if my question was unclear or I have misunderstood your answer.
 
Hi

I have my own small N scale layout and work with a friend who has a very large G scale garden railway. My own layout is fully automated and I am in the process of automating the G scale layout. I have set the system up in blocks using one rail as the “live” rail and the other as the feedback rail which is insulated at both ends. The system I am using senses current flow in the block when occupied. I initially controlled with arduino micro controllers but I am not a good programmer and the result proved to be to inflexible.

I am now using iTrain as the computer program to control both systems and while it takes some time to understand the program it is excellent when running. I don’t know what ABC is or how it works but is sounds complicated, the current feedback system is simple to setup and when the computer program is understood very flexible. There are around 50 YouTube video tutorials available to explain the program.

Points should not be included in the blocks for the iTrain setup but this is specific to the program.

just a thought if you are still in the planning stage.

Robin
 
Airbuspilot said:
Hi

I have my own small N scale layout and work with a friend who has a very large G scale garden railway. My own layout is fully automated and I am in the process of automating the G scale layout. I have set the system up in blocks using one rail as the “live” rail and the other as the feedback rail which is insulated at both ends. The system I am using senses current flow in the block when occupied. I initially controlled with arduino micro controllers but I am not a good programmer and the result proved to be to inflexible.

I am now using iTrain as the computer program to control both systems and while it takes some time to understand the program it is excellent when running. I don’t know what ABC is or how it works but is sounds complicated, the current feedback system is simple to setup and when the computer program is understood very flexible. There are around 50 YouTube video tutorials available to explain the program.

Points should not be included in the blocks for the iTrain setup but this is specific to the program.

just a thought if you are still in the planning stage.

Robin
Click to expand...
Thank you. This is really useful. Can I seek a bit more clarification on how you have isolated your blocks?

When you say one rail is the 'live' and the other is the 'feedback rail which is isolated at both ends', does this mean that the 'live' rail is electrically connected throughout the layout and the 'feedback' rails are effectively sub-divided into the sections which are electrically isolated at each end (and therefore define the start and finish of each block)? Do you have any rail sections where both rails (ie live and feedback) are electrically isolated?

Your comment re iTrain is interesting too. It is starting to become clear to me that iTrain and Train Controller software need points outside their 'blocks' and are capable of ignoring sections of track with points and crossings as far as occupancy is concerned. In contrast, JMRI seems to require a 'continuous' uninterrupted sequence of blocks and therefore it is necessary to have to be some blocks with points in them. Very happy to be proved wrong on this observation.

I had decided, naiively perhaps, I would try to put off selction of train control software until sometime in the future as both iTrain and Train Controller look expensive. Even so, I didn't want to predjudice any future decision because I had already laid track with isolating rail joints in the wrong place.

Re ABC: this is infact a very elegant and simple solution for a 'semi-automatic' layout as it will automatically slow trains to stop at a predetermined point (such as a signal at danger) and then allow them to restart when the circuit is overridden. Again, online vidoes explain - the one by Megapoints is particularly good. I'm assuming that ABC is rendered redundant as soon as train control software is introduced as the software will decelerate / accelerate trains depending on the state of following block sections? In hindsight, including a question about ABC in my original post was probably a bit of a red herring. Apologies.
 
For my layout I have a space constraint (wife) I have a pair of tracks up line / down line in a station as the main point of focus. The tracks split at the end of the station making two double track loops, the outer loop goes to a small fiddle yard and the inner just a loop where the train can hide before coming back to the station. This means the trains can cross the main line at each end, this was the most complex layout I could manage in the space available. iTrain controls up to 3 locos on each loop randomly with no problems, if a train is in the station the incoming train has a red light and stops short of the station, same with the crossing.

My layout has a continuous outer rail on each loop as the “live“ rail, the inner rail of each block is isolated at each end with a standard plastic rail joiner, each block feeds back to its own current sensing point in the detector.

The G scale layout is very large, single track and bi-directional. The same system applies, I have a “live“ outer track and each block has a feed back wire to its current sensor. Points and some dead sections (un-sensed) are measured and iTrain calculates where the train is on those sections. The only places where I have both ends of the block insulated are where I need a reverse loop. All the feedback cables in the G scale use current transformers as detectors, for the reverse loops one cable is sensed.

I have iTrain Plus on both layouts, I use the decoder programming function built into the program and I need two screens for the G scale railway. You can operate without decoder programming, I find it useful. Try the two month trial period, its fully functional and runs in a demo mode without a layout.

Robin
 
Airbuspilot said:
For my layout I have a space constraint (wife) I have a pair of tracks up line / down line in a station as the main point of focus. The tracks split at the end of the station making two double track loops, the outer loop goes to a small fiddle yard and the inner just a loop where the train can hide before coming back to the station. This means the trains can cross the main line at each end, this was the most complex layout I could manage in the space available. iTrain controls up to 3 locos on each loop randomly with no problems, if a train is in the station the incoming train has a red light and stops short of the station, same with the crossing.

My layout has a continuous outer rail on each loop as the “live“ rail, the inner rail of each block is isolated at each end with a standard plastic rail joiner, each block feeds back to its own current sensing point in the detector.

The G scale layout is very large, single track and bi-directional. The same system applies, I have a “live“ outer track and each block has a feed back wire to its current sensor. Points and some dead sections (un-sensed) are measured and iTrain calculates where the train is on those sections. The only places where I have both ends of the block insulated are where I need a reverse loop. All the feedback cables in the G scale use current transformers as detectors, for the reverse loops one cable is sensed.

I have iTrain Plus on both layouts, I use the decoder programming function built into the program and I need two screens for the G scale railway. You can operate without decoder programming, I find it useful. Try the two month trial period, its fully functional and runs in a demo mode without a layout.

Robin
Click to expand...
Thanks again. I think I'm now reasonably confident I know what I need to do re track isolation. My planned layout is essentially two continuous circuits. The outer one is primarily to serve storage loops under the eaves of the loft with two connections to the inner. The inner has two through stations with various passing loops and sidings and will be the more scenic of the two.

I have decided that I will use isolating fishplates on both rails on the lines interconnecting the inner and outer circuits so that I could use a separate DCC command station and booster if current draw becomes a problem. All other lines (ie each circuit and its respective sidings and loops) will broken down into blocks isolated using insulated rail joiners on the inner rail only. In my case, I adopt the policy of 'black to back' so this will be the 'common negative' of the DCC supply with occupancy detection (Megapoints current sensors) on the positive feeds to each block on the inner rail.

I have wondered about downloading trial versions of the paid-for software packages (I already have JMRI which is free) but I think they are time limited so I was hoping to leave it until after debugging all the automation hardware with simple mimic panels. With the later Megapoints equipment, it is fairly easy to interface with train control software via MQTT.

With your experience, does any of that sound stupid?

Thanks,

Richard
 
Has anyone uses the AZATRAX or azatrak.com infra red control system.
It is a US company and I have not looked into prices and duties but I very much liked the principal . A loop loogs simple.
I have a dog bone layout waiting for warmer weather. I have a Piko battery operatey yard loc that runs on 9 volts but it is not exciting.
A late Happy New Year.
 
Sounds good to me Richard.

For the iTrain program, I had already decided this was my program of choice so the trial period allowed me to confirm my choice before parting with the money. It also allowed me to try several variants on my eventual layout while still planning.

Robin
 
Thank you Robin.

Hadn't thought about the relationship between the control software and track layout before. Only problem for me is the number of constraints on the layout due to loft beams! But food for thought.

Regards,

Richard
 
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