Hornby Point/Accessory Decoder

[81F]

Over the weekend I hope to fit my second Hornby Accessory Decoderbut have a couple of questions relating to it's programming and output.

 

The problem is that on nthe finalized layout second decoder will not be controlling points 5 to 8 but 10 to 13 which does not fall within the usual blocks of four. As I see it I have two options.

 

Option 1: Use two Hornby decoder units to control points 1 to 8, someone elses single unit for point 9 and the decoder I am fitting this weekend to control 10 to 13. If However, is it easy to programm one Hornby decoder to use addresses 10 to 13 rather than 9 to 12. and if so how. Please note that as there will probably be another haf dozen decoders after this (assuming that I change the branchline points as well) I would like to avoid programming each output individually.

 

Option 2: Keep it simple, albeit potentially wasteful. As option 1 but use a Hornby decoder for point 9, waste addresses 10, 11 and 12 then program the decoder I am fitting this weekend between 13 and 16 and re-allocate my point numbers to suit?

 

If I go for option 2 I might be able mitigate the loss due to wasted addresses by reprogramming the outputs to give a constant voltage to power building and yard lamps but this depends upon the output. So can someone also tell me what the constant voltage  would be and is it DC?

 

Many thanks for any help.

[Chrissaf]

I have a suspicion that you will not be able to deviate from Hornby's R8247 Accessory Decoders numbering scheme. The R8247 uses something called 'Group Addresses'.....Group Addresses are predefined by Hornby as follows (image extract taken from R8247 user guide.....read the guide for further information):

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/media/tinymce_upload/eddaf0bc94c575bf0e5566a04cbf6125.jpg

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RailMaster having intelligence in software effectively does the 'Port Address' to 'Group Address' conversion for you in the background. Which is why in RailMaster you configure the R8247 using 'Port Addresses'. I do not think it is possible to start a R8247 (first port) at port address 10, as that is not compliant with the R8247 Group Address numbering scheme. However that said, I have not tried it to test the theory.

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Why are you reluctant to modify your point numbering scheme on your track plan to make it fit with the decoder port numbering.

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With regard to the second part of your question.

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When you configure a R8247 port for 'Always On' the output is DC and about 14 volts. Note however, that the current shared for all four decoder ports is 240mA. This limits what you can connect to the decoder as you need to carefully plan your power consumption. Also, if you have one or a couple of ports dedicated for solenoid points, the internal CDU recharge will likely be affected if a significant amount of that 240mA is being hived off for lights. Either that or the lights may dim or go out every-time you throw a connected point, because the discharged CDU capacitors offer a lower resistance path to the current within the decoder.

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Note: The maximum shared 240mA current figure was quoted by Hornby Customer Care services in the 5th post up from the bottom on this previous topic thread:

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https://www.hornby.com/uk-en/forum/dcc-operated-signals/#post3954

 

 

[Fishmanoz]

I think it's pretty clear from the documentation that group addressing is the only thing they can do. Also, these decoders have a nasty habit of reverting to default from time to time. As a result, it is best not to number any points 1-4 as when you go to throw any of them, you may also throw another point at random on the layout if it has reverted.  And reversion will also have consequences for any lighting attached as the decoder will be back to pulsed instead of continuous. 

[96RAF]

Indeed Fishy that reversion to pulsed for any port set previously for a continuous output is a good basic indicator that the decoder may have gone back to default settings.

 

So if your 'lights' just flash once rather than stay selected on it is very likely the decoder has took the hump for whatever reason.

 

I also concur that these decoders use group addressing methodology and you cannot split the designated group port address across decoders or map them to other numbers unfortunately.

Rob

[Fishmanoz]

It still amazes me that, these decoders having been off the market for over 12 months fixing a severe reliability problem, Hornby didn't change to a modern design with learn mode programming, more flexibility and no reliability problems. 

[96RAF]

It still amazes me that, these decoders having been off the market for over 12 months fixing a severe reliability problem,

Can you expand on that Fishy. I thought it was just a supply chain problem associated with swapping factories.

Rob

[81F]

 The bit about the fault worries me as I have bought eight of them before the concession shut down. As to numbering, it's not that I am adverse to renumbering the points just using a four output decoder to power one point and waste three outputs especially as this is going to happen again as I work sown the line with these decoders and may result in me having to buy three more!

 

In order to use all ports on the decoder I would have to install several very long wire runs (about six foot) which I would like to avoid.

 

Any way thanks for tellingt me that I have to use the Group Addressing.

[96RAF]

All my acc decoders are mounted on a common relay panel installed at one end of the layout and on my old layout which was an L shaped 12'x 5' some of the point runs were a lot longer than you propose 81F and they were totally reliable so don't be put off by 6' runs unless off course you have board joints to cross with disconnects or some other reason for not wanting long runs.

Rob

[Chrissaf]

Like Rob, all my R8247s are centralised in one single location with wiring for my 17 points radiating out in a 'star' configuration. For me, I don't find this an issue particularly as my baseboard is one complete fixed size and not built in transportable segments.

[Fishmanoz]

Rob, I don't have any specific information on reliability v just a supply issue except we know from forum posts before they went off market that they were showing a very high failure rate of either single ports or the entire unit.  No idea if that was design or production or both. If all they were doing was changing supplier, that is a worrying issue for me on the possibility of a design weakness still being there. Also we know from subsequently reported faults that the decoder still has at least some issues. All in all, not my favorite accessory decoder when you compare across the market today. 

[96RAF]

I remember the odd posting of failed ports Fishy but a forum search on R8247 or accessory decoder failed to get me to the root problem.

 

From memory many problems were resolved either by a reset (value 8 to CV8 just like a loco decoder) or by following the script..

Rob

[wbillb]

Hi I'm a complete novice! I have a layout with 6 x points and 2 x remote uncouplers (all hornby)

I also have 2 x R8247 decoders for points/uncouplers all this using Railmaster on PC and e-link

The instructions with the points decoders only are for 'Select or Elite' controlllers not a mention of e-link

I have managed to program one decoder to control 4 points and is working OK, but when I disconnect it to program the second decoder using ports 5,6,7,8 when I try to operate my points 5,6 and uncouplers 7,8 nothing happens? I noticed on the railmaster software it showed ID:25.5 after programming first decoder also after programming the 2nd decoder ID:25.5 is this normal? Any help would be appreciated in programming 2nd decoder.

 

[Chrissaf]

The instructions for programming the R8247 using eLink are in the RailMaster user guide manual pages 73 to 76

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Ignore everything you have read on the R8247 user guide sheet (as you say, those instructions relate to configuring the R8247 using Select and Elite controllers). Configuring the R8247 using eLink is a completely different process.

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Out of the box, the R8247 is configured with the four ports having DCC Addresses 1 to 4. For your second R8247 you need to configure the first port of the R8247 as DCC address 5. Doing this will automatically configure the other three ports 2, 3 and 4 as DCC Addresses 6, 7 & 8.

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The 2nd R8247 needs to be the ONLY device connected to the 'Prog A&B' terminals of your eLink during this configuration process. Once successfully configured as DCC Addresses 5 to 8, you disconnect the R8247 from the 'Prog A&B' terminals and reconnect it to the 'Track A&B' terminals on the eLink to test and operate it. The 'Track A&B' terminals will also be connected to your first R8247 as well as the 2nd R8247 as well as your actual layout track connection. All the attached devices are connected to the eLink 'Track A&B' terminals in parallel.

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To operate your attached devices, you will also need to create your track plan in RailMaster, where you place point and decoupler icons on the track plan and configure the icons with the appropriate DCC addresses used by your R8247 decoders i.e. DCC Addresses 1 to 8.

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That's the basics, the details of programming the R8247s are in the manual on the pages I have identified. Note: designing the track plan instructions start on page 77 of the RailMaster manual.

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Just in case there is some confusion. Creating your track plan and assigning DCC addresses to the icons (such as point icons and coupler icons) DOES NOT program the DCC addresses into your R8247 Accessory Decoders. The track plan just tells RailMaster what address to send digitally to the eLink track output to operate the selected device. Prior to using the track plan to operate the attached decoder device, you also have to configure the DCC Address in the R8247 decoder as per page 73 to 76 (with the exception of DCC Addresses 1 to 4 for the first R8247 as these are the factory configured default).

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It is probably because the default DCC Addresses are 1 to 4, as to why your first four devices are operating correctly. Devices that you intend to use DCC addresses 5 to 8 for, are probably not working because you haven't yet successfully programmed these addresses into your second R8247.

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PS - I don't recognise the term ID25.5. Posting a 'screen shot' that shows what you can see on screen would help a lot. To post an image use the 'Black & White Hill & Moon' icon. Note that images are reviewed by the forum administrator (office hours Mon-Fri) before being visible on the forum, so there may be some delay before forum members (including yourself) can see them.

[wbillb]

Hi Chrissaf thankyou for your speedy response, I believe I was programming the 2nd decoder properly ie.only item connected to PROG A&B on e-link then selected program icon at top of screen, as shown below/media/tinymce_upload/b1aa347299d742fcfb67733537ec1938.jpg

as you can see after reading the decoder it shows by my circle ID25.5 near bottom, I then changed the Output ports to 5,6,7,8 & the Pulse Duration to 100ms. I then pressed bottom left icon to program decoder./media/tinymce_upload/f4a96ca51bacd74507719ffc9cc48bdd.jpg

/media/tinymce_upload/51276fc9c0998add76f2423d53c43810.jpg

After completing above I put the cable to TRACK A&B reconnected 1st decoder then tried to switch points 5,6 and uncouplers 7,8 STILL NO JOY! Below is a screenshot of my Track Plan.

/media/tinymce_upload/b10b8f81c1007b2a05a39d16925628a3.jpg

As you can see I have decoder port 5 for this point --- Totally flumoxed!! I did try to reprogram 2nd decoder as a 1st with ports 1,2,3,4 and this worked OK proving decoder operation. any ideas?

[ff2nd]

A word to the wise. If you are using a Select, and intend to use the R8247, make sure that the firmware on the Select is up to date. Trawling back through very old posts, it seems that older firmware on the Select could cause issues, and even port failures. These seem to all but stop if the Select is updated.

[Chrissaf]

Apart from the first screen shot that shows an address of 6629 (the maximum permitted address range is 0001 to 2048 or thereabouts) the rest of the screen shots look normal. The reference to ID25.5 has nothing to do with point addresses. All my R8247s (three) have that ID number showing too in that screen location.

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Two things you can try:

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Firstly, given that the first screen shot showed a very unexpected configuration (address 6629). I suggest performing a factory reset of the R8247. Unless you have RailMaster ProPack you cannot do a reset within the R8247 programming screen. Performing a factory reset using RailMaster standard edition of a R8247 is described in this previous thread (4th post down on the page). Once reset, re-address as ports 5 to 8 and try again. Its been a few years since I last programmed a R8247, but if I recall correctly, after writing the DCC address using the pencil icon in the bottom left corner, if you click the green arrow in the right hand corner, the configured address will be read back. Do this to confirm that addresses 5 to 8 have been set and accepted correctly.

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https://www.hornby.com/uk-en/forum/post/view/topic_id/9065/?p=2

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Secondly, when you were creating your track plan and placing the point operating buttons on the point icon. Did you notice both the red and the green button 'snapping' to the correct positions on the point in the plan. Or did you place the red & green buttons manually one at a time. If you didn't get the 'snapping' action, it can lead to odd operational issues occurring.

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You could try deleting the point port address 5 buttons from your track plan and add & configure them again, making sure that you observe the 'snapping' action.

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To make the red & green buttons snap to their positions. Left mouse click and hold a button icon from the left hand selection column (it doesn't really matter which colour) and drag the mouse pointer to the centre of the point icon on screen and release the left mouse button. If you have hit the 'sweet' spot on the point icon, then both the red and the green buttons should appear (snap to position) on the plan in their correct positions. Right click a button and configure the point settings (such as address 5 for example). Re-save your track plan, exit and restart RailMaster then test point operation again.

[96RAF]

A word to the wise. If you are using a Select, and intend to use the R8247, make sure that the firmware on the Select is up to date. Trawling back through very old posts, it seems that older firmware on the Select could cause issues, and even port failures. These seem to all but stop if the Select is updated.

 

Apart from the fact you can only use Select as a Walkabout to an Elite with RM, the problem with point addressing of early firmware Select is the way it handles the numbering by an offset of three and the fact you need the Elite in Classic, mode to compensate, when RM needs it in Standard mode. Another good reason for updating your early  Select by way of Hornby if you use it as a walkabout.

Rob

[wbillb]

Hi Chrissaf once again thankyou for your help, I upgraded to the PRO version of railmaster, then attemped to set the decoder to factory settings by putting 8 into CV8 then programming, after reading decoder I was getting the same port addresses ie. 6629 etc. I totally removed the decoder from the layout and directly coupled it to the e-link PROG A & B then again read the decoder a lo and behold it came back with ports 1 to 4/ 100ms I then set ports to 5,6,7,8 and wrote to decoder and this time it worked, put it back on layout & tested points they all worked OK finally! Have come to conclusion you need to set decoder up totally off layout & directly connected to e-link PROG A & B. Once again thx for you help.

[Chrissaf]

@wbillb,

OK finally! Have come to conclusion you need to set decoder up totally off layout & directly connected to e-link PROG A & B.

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That's exactly what I said in my first reply (4th paragraph down)..........replicated below:

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The 2nd R8247 needs to be the ONLY device connected to the 'Prog A&B' terminals of your eLink during this configuration process. Once successfully configured as DCC Addresses 5 to 8, you disconnect the R8247 from the 'Prog A&B' terminals and reconnect it to the 'Track A&B' terminals on the eLink to test and operate it.

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Note1: When I say the "ONLY device" this also includes loco decoders. Do not try and programme a R8247 with your track connected to the eLink 'Prog A&B' terminals with locos sitting on the track as well........recipe for disaster. Always disconnect the R8247 being programmed from the track and connect it directly to the eLink  'Prog A&B' terminals.

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Note 2: Most of the NON Hornby Accessory Decoders can be programmed in-situ on the layout (self learning mode decoders). The Hornby R8247 cannot be programmed this way and needs to be programmed as described above.

[Fishmanoz]

CHRIS, I'm a little sympathetic to wbillb on this.  You can read until you are blue in the face but if your brain is thinking otherwise you may well not see the reality of what the words are telling you.  I know from my own experience.