Block Control [using 'Brake on DC' decoder function]

[Chrissaf]

It sounds like you need a controller capable of changing CV29. Not all controllers can do this. The current pre 1.6 firmware Select controller for example cannot do this. So assuming your controller is capable of changing CV29. You need to modify the value of it to disable "DC Operation".

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This website explains CV29 and how changing its value modifies the loco behaviour.

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If you were to state the product brand and model of the 'block controller' that you have purchased, then we could search for the 'online manual' if one exists to see if there is anything in it that would provide a simpler more elegant solution to your issue. Personally I cannot think of what product it might be, as I have never heard of a DCC product that purposely sends DC to a DCC track.

[Keith2414]

Thanks for replying back so quick, I will try CV29 and see if I can turn it off, I will let you know how I got on tomorrow. The Block controller is from www.blocksignalling.co.uk, and it is a DCC controller.

Thanks again

Keith

[Chrissaf]

For all,

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For the info of other readers who might be interested in this product. There are two versions the A version and the B version. The A version supports the control of LED signals that are wired as 'Common Cathode' and the B version is for signals wired as 'Common Anode'. The link below is for the A version.

http://www.blocksignalling.co.uk/index.php/section-controller-sec4-dcc

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Keith,

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If the CV29 calculator website still confuses you, then use your DCC Controller to read the value of CV29 for the decoder fitted to your loco. If the value of CV29 is currently 6, then write a value of 2 back to CV29. If the value of CV29 is 34, then write a value of 30 back to CV29. These new values of 2 or 30 will disable 'DC Operation'. Repeat this for all the locos in your fleet that are going to use this 'block section control' product.

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This does assume that the CV that the retailer is referring to is indeed CV29 and not some other CV entirely. The website documentation and downloadable manual is not specific enough to tell.

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Having read the manual, I can see no clearly documented reason in it as to why the module switches the isolated track section from DCC to DC.

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If CV29 was a key configuration requirement to be performed i.e disabling 'DC Operation'. I would have expected it to be stated clearly in the manual. I have a suspicion that the retailer is suggesting amending the CV as a 'work-around' to get over the issue of their product not doing what you are expecting it to do. Maybe your isolated section of track is too short, or not configured correctly.

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If the isolated section is too short, then maybe your loco starts to slow down, but crosses over onto the next live DCC section before it has come to a standstill. By disabling 'DC Operation', the loco would be expected to stop more abruptly and therefore guaranteed to stop before the next DCC live section of track.

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Anyway, these are my thoughts on the matter. They may offer you some further assistance to try some further diagnostic tests.

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[Rog RJ]

Brake on dc is a common feature found on many decoders.  Often called ABC braking.

[Chrissaf]

Ah yes.....now you've jogged my memory Rog, I remember seeing that feature mentioned before. But isn't it a case that you need to use a DCC decoder that specifically supports that feature? Wasn't it developed by Lenz and included as standard in their decoders. In that case, I would presume that the retailers comment about changing a CV, probably related to something to do with that feature more so than anything to do with CV29. Unless the retailer was suggesting CV29 'DC Operation' as a 'work-around' for decoders that do not support the proper 'ABC Braking' feature. It would have been helpful if 'Block Signalling' had included in their documentation a comment to that effect, if this feature was a necessary support requirement for their product to function correctly.

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Keith,

I think that Rog (RJ) has given a significant clue.....I suggest you check the documentation for the decoders you are using and check to see if they support the 'ABC Braking' feature. I have just had a look at the R8249 datasheet (should you be using that Hornby decoder) and it is not mentioned. It's possible that to fully implement a working solution, you might need to replace all your decoders with Lenz ones. I suggest further dialogue with 'Block Signalling' might be prudent to confirm.

[2e0dtoeric]

If Keith has 'stay-alive' decoders fitted, they would ignore the momentary interruption to power anyway!

[Phil_Spiegel.]

A major problem with using 'block control' to control train behaviour is the absolute need for the sections to be longer than the longest train in use, because any metal wheel in any part of the train ( as with auto reversing sections) will link  the adjacent sections ...thus, in this case, negating the switch on braking, because DCC will still be received.Alternatively, if a traiñset like an HST was run with only plastic wheels on all but the powered power car, the start of braking position would vary by almost 2 train lengths depending on which way round it was running.

All push-pull trains would experience a similar effect.

This is one reason my preference is for using non-track-based section of train position... In my case optically.

This will always detect the front and rear of any formation of train. Is traçk occupation.

Physical track sections work on smaller layouts for services like trams.... Where train length is short, and fairly uniform. Eg single vehicle, or 2 or 3 car articulated .  however, automation of running çan still experience problems without matching ,tram-like' braking, if , in slowing, the tram overrun s into the next section.

I would still like to see the proposed Hornsby optical detection and identification system make its public appearance. .... An optimal solution ???

[96RAF]

The OP says he is using ir detection Phil.

[Keith2414]

I am gratefull to all who have replied, thanks. I am a beginner you might say at 70, I have had the bug since I was young, but have not found the time to start, so all these replies are like gold dust to me. I do not feel alone

I have looked at cv29 and found that DC was already disabled, I will do the rest of the sudjestion and tell you all of my result.

[Keith2414]

Hi again,

I have tried the above sudjestions and none have worked, with referance to changing my decoders, expensive but if nessisary to solve the problem I will concider it.

Iwill email Block signalling to see what they say.

I run my layout with a Hornby Elite conected to a laptop with the Pro update.

Thanks

Keith

[96RAF]

If you are trying to use RM to control your trains by way of your IR detection then there is no facility yet and when it comes it will be Hornby’s proprietary system. However you can still use your IR system to slow or stop a train if as has been said before your decoder supports either ABC or ADCC - i.e. brake on DC. If the decoder does not support this then the decoder is blind to any such signalling.

[Keith2414]

If you are trying to use RM to control your trains by way of your IR detection then there is no facility yet and when it comes it will be Hornby’s proprietary system. However you can still use your IR system to slow or stop a train if as has been said before your decoder supports either ABC or ADCC - i.e. brake on DC. If the decoder does not support this then the decoder is blind to any such signalling.

Hi

Thanks for your info, the detection controllers are stand alone and a control bourd controls the ir detection, control bourds cane be linked together controlling each block and changeing light signals, stopping trains on a red light if the next block has a train in it, also it will show yellows when apropriate.

 

Thanks

Keith

Keith

 

[96RAF]

Presumably the blocks go electrically dead upon detection/signal hence any decoder should work, but you will lose any sound. It is only if you are using IR to invoke brake on DC that you need specific decoders.

 

Tip- avoid using the blue button it just camouflages your reply within the previous text.

[Chrissaf]

Presumably the blocks go electrically dead upon detection/signal hence any decoder should work.....

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Rob, have a read of the product user guide manual PDF on this link:

http://www.blocksignalling.co.uk/pdfs/44KF1S.pdf

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Put very simply. There is a 'block section' of track that has an ingress IR detector and an exit IR detector. Prior to that section of track is a 'Signal' and prior to the signal is a section of isolated track.

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Assume the ingress signal is at Green (no train within the section between the two ingress & exit IR detectors). A new approaching train triggers the ingress IR detector. The control board changes the isolated section of track from DCC to DC. The train that triggered the ingress IR detector is unaffected as it has already entered the ongoing DCC powered section and continues on its journey between the two ingress and exit IR detectors.

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Meanwhile any train that is following on behind will be approaching the signal now at red. The loco needs to support 'Brake on DC' so that the isolated section (now DC) forces the following train to stop at the red signal.

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Now assume that the train that is already in the block section between the two IR detectors, reaches the exit IR detector and now triggers that. This will cause the ingress signal that is at red to change to green or yellow (depending upon aspect) and restore the DC power to DCC. The stationary train now sees DCC track signal and resumes its last command, so it moves off to regain its previous speed and direction.

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Multiple 'block sections' each with their own controller can be cascaded together so that a series of sequentially arriving trains can stop and start as each block is occupied and cleared. The signals also cascade through their colour sequence depending upon aspects.

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My reading of the manual infers to me that only decoders with the 'Brake on DC' support are going to make the 'block section control' workable. Brian Lambert (our own Flashbang) has a webpage on his site for 'Brake on DC'....see link below. It states that 'Brake on DC' requires CV29 'DC Operation' to be disabled and a suitable supporting DCC decoder fitted for 'Brake on DC' to function.

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From what I have read, my understanding is that 'Brake on DC' is a different decoder feature to 'Asymmetric DCC' braking and/or ABC?.......but I may be wrong.

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https://www.brian-lambert.co.uk/DCC_Page_2.html#Bookmark5

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PS - We (members) on the forum are always stating that DC and DCC voltages should never be mixed on the same layout track. The difference with this product is that the DC voltage is derived from the DCC supply using a 'bridge rectifier' integrated within the controller product. This is not the same as connecting a separate DC power supply source to the same track that a DCC controller is attached. The DC voltage in this instance is derived from the same DCC power pack and share a common return path. So I can only assume that this 'sharing the same power supply' and controller output makes it safe to do.

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[96RAF]

Thanks Chris, I had assumed a simple block shuffle up system, such as you could apply to an auto-staging fiddle yard. Revert my previous statement to read ABC/ADCC capable decoders.

 

There is a difference between ABC and ADCC which folk can self research if interested, as I have to go out to buy wood for a layout.

[Chrissaf]

After a bit of Googling I have found some info that may be of use.

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Firstly, just to clarify. There is a difference between 'Brake on DC' and 'Asymmetric DCC' and 'ABC'. ADCC and ABC are not the same functions as 'Brake on DC' technically in operation.

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Note to Keith.

Note in the image below that the 'polarity' of the DC condition applied to the isolated track piece will affect whether the feature works or not. Check your wiring to ensure that you have wired the isolated track section the right way round.

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To further support the above, this statement found too, from Brian Lambert who wrote the webpage info previously linked in one of my earlier posts.

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So what decoder brands support 'Brake on DC' ?

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This has been a little bit harder to find a definitive list of brands, but here are some examples I have found on the net after a brief search.

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• LaisDcc (Note however, there are many issues reported on the forum when using LaisDcc decoders on Hornby controllers)
• TCS. (This brand seems to have favourable comments consistently on the forum).
• Hattons own brand. (These also occasionally come up on the forum with issues with Hornby controllers).

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[Chrissaf]

Hi

I have a Block controller which uses infa-red sensors under the trach and an isolated peice of track. When a train passes the first sensor the controller turns the DCC power to DC on the isolated track therefor stopping another train entering the section until the first train has passed the second centre, it then returns DCC power to the isolated track releasing the second train.

My problem is that my trains will pass over the DC powered track and do not stop, the supplier states that there is something to be changed in the cv"s. Not being very compitent with this sort of thing I thought there may be someone out there that can help.

Thanks

Keith 

[Chrissaf]

Keith's post text reposted with personal email address removed.

Keith, Personal mails are a breach of forum guidelines. You can capture the PDF as images and post those instead.

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Windows includes a screen capture utility called 'Snipping Tool' this will save a selected area of screen as a JPG file. Once it is a JPG file you can then post that on the forum as an image.

How to post an image

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Hi everyone.

 

At last I have it working and it is great to watch four trains on the same line, going at different speeds, stopping and starting with red, yellow and green lights working.

 

It was not easy as the instructions are not very specific, anyway 'Block Signalling' sent me a sheet and I carried it out and hey presto it worked. I had my live on the left rail, from the drivers view, I changed that, I then configured my CVs as per the attachment and the train stopped, then carried on when the next block was empty. A great and cheap product that works.

 

I would like to thank everyone involved and I will continue to look at the blogs in future.

 

Kind regards

Keith

 

PS. I have tried to attach the file but it will not let me, the jist of it is, make sure CV29 has the DC turned off, then put CV4 to 5 or below. I did this on my Hornby 08 with sound and it worked great, the train comes to a slow stop, not an abrupt one.

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If anyone is interested in the instructions please Email me at [email address removed] and I will try and attach it to my reply.

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[Chrissaf]

Keith, You say it works with your Hornby 08 with Sound. For the sake of clarity can you confirm whether this is a Hornby TTS 08 decoder or another alternative 'sound decoder' brand. And if so, what one.

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You say you have four locos performing correctly. For the benefit of others that follow, can you be specific regarding what decoder brands are installed in the locos?

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It would be appreciated to know the decoder detail, given the resources given by others to try and help you with this issue.

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You wrote:

....I had my live on the left rail, from the drivers veiw, I changed that....

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So presumably, the comment I made in my last reply about getting the isolated track section wired with the right polarity was correct, and you had it wired the wrong way round. Question: Was it your installation error with the wiring OR was it an error in the manual showing the wiring the wrong way round?

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PS - I am really pleased that you have got your issue resolved without having to resort to more investment in alternative decoders.

[Flashbang]

Just to be clear.... The basic Hornby R8249 decoder does not support Brake on DC.  It doesn't support Asymmetric (ABC) braking either!

[Keith2414]

Hi Chrissaf

Just to clear your quiery, my 08 is with the Hornby sound decoder as fitted, not TTS, all my other decoders are Hornby basic ones. As regards the wireing, I had put my live that way around thinking it would not make a differance but it did, a loco is wired with the brown pickup wire on the right and the black on the left, not a problem normaly.

Thanks 

Keith

[Chrissaf]

....my 08 is with the Hornby sound decoder as fitted, not TTS.

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In that case the Rnnnn number for your 08 Class loco probably has an XS suffix ie. RnnnnXS and will be an ESU Loksound decoder. I have one of those and mine is a 21 pin Loksound V3.5 fitted decoder.

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Strange that the others are basic Hornby ones, as Flashbang is adamant that the basic R8249 doesn't support 'Brake on DC' whereas your experience is that they do. How strange.....

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Sorry to be picky, but I'm still not clear on your description of the wiring. Did you initially (when it didn't work) wire the isolation track as per the manual or the opposite way round to the manual. For clarity, I am referring to the 'red and black' wires circled in the image below, taken from the manual:

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I ask for the detail as I am trying to work out if the manual has an error in it or not.

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I am of the opinion that the manual shows the correct wire orientation. The evidence for that is that under normal DC operation, for the loco to travel to the right as shown in the above image. The bottom (right rail) would be positive. However 'Brake on DC' operates by reversing the DC polarity (see yellow highlight in text box below). In other words, putting the negative (black wire) on the bottom (right rail) instead of the red....as shown in the manual. The loco doesn't go into reverse, because CV29 'DC Operation' has been disabled.

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[Flashbang]

My comments follow a problem with BoDC when using a Hornby decoder and a email to Hornby who replied and stated their decoder - R8249 does not support BoDC!   If since then (about two years ago) the decoder has seen an upgrade then its obviously altered, but it was not compatible and confirmed as so by Hornby!

 

Decoders are wired Red to right hand wheel set (not Brown) and Black to the left hand wheel set when facing forward.  Orange and Grey are to the two motor tabs.  All other coloured wires (Blue, White, Yellow, Green and Violet/Purple) are for functions.  Frequently Brown coloured wire is used for speaker connections.

[Keith2414]

Hi all.

I would like to be able to send you the leaflet which I got from Block Signals but when I try and do it, I get a message that I am unable. It is a pdf file in my photos files, it tells me the file type you are unable to download. As you can see I am not good on computers. any answers keep it simple.

Keith

[Chrissaf]

The following screen shots taken from a Windows 7 PC....they are similar in Windows 10.

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Step 1

Open your PDF file so that you can see the contents on screen in Acrobat Reader.

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Step 2

Now assuming you are using a Windows PC, type "Snipping" in the 'Start Menu' search box......bottom yellow highlight in image below. This should find the 'Snipping Tool' .......the top yellow highlight in the image below.

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/media/tinymce_upload/40bd1c723eb432d257163c86d8a479cc.jpg

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Step 3

Double click the 'Snipping Tool' entry in the top of the search box to open the utility. You should get a dialogue box to open like this one. Make sure to select the 'Rectangular Snip' option in the pull down menu, by clicking the little 'down arrow' to the right of the 'New' button.

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/media/tinymce_upload/40821bb8ea9ed47c140d2403c5d2e9dd.jpg

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At the same time as the dialogue box above appears, the screen should fade out and a 'cross cursor' icon should appear on screen. If the faded screen and 'cross cursor' icon don't appear, click the 'New' button on the Snipping Tool dialogue box.

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Holding the left mouse button down, drag the 'cross cursor' around the perimeter of the PDF document window.

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Once the contents of PDF page is enclosed in the selection box, release the left mouse button and a dialogue box will open asking how you want to save the image. Save the image as either a 'PNG' file or a 'JPG' file to a location on your hard drive.

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Step 4

If the PDF file is more than a single page long, then repeat the process above for the other PDF file pages (if any).

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You should now have either a single image or multiple image files on your hard drive that have captured your PDF file pages in an image format.

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Step 5

You can now follow the guidance in my earlier reply that gave a link to a 'How to post an image' thread. To add these captured images to this thread in a new post. Note that images need to be approved by the forum administrator (not a Mod) and are unlikely to appear before tomorrow if posted tonight.

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