Ant Bennett Posted November 2, 2012 Share Posted November 2, 2012 I have 7 x R8247 accessory decoders controlling points via a Select controller, programmed starting at address 61. All has been working fine for a few months until yesterday when I noticed that two decoders (starting addresses 81 and 85) stopped switching their points after setting up an cancelling a Consist. I have connected each R8247 directly to the Select and tried to reassign the addresses but when I set the 'LA' I just get 3 flashes on the LED and the first output works to throw it's point but not back again, and then no other outputs work. Do I need to reset these docoders? Can I do that with a Select or do I need to upgrade to an Elite? If I upgrade, will the other accessory decoders still work OK or would I need to reset them all and start again? Link to comment Share on other sites More sharing options...
Rog RJ Posted November 2, 2012 Share Posted November 2, 2012 I'd try resetting the Select before doing anything else, described on page 19 of the manual. Link to comment Share on other sites More sharing options...
Ant Bennett Posted November 3, 2012 Author Share Posted November 3, 2012 Thanks Rog, I have tried that but still can't get two of my R8247's to work. I guess the next thing to try is resetting them back to factory settings amd then reassigning them? Having looked at the Select and Elite manuals it looks like I can't do that with the Select. I was planning on upgrading to an Elite at some point, so maybe this is a good time... Link to comment Share on other sites More sharing options...
poliss Posted November 3, 2012 Share Posted November 3, 2012 Check that the ends of the wires are clean. Link to comment Share on other sites More sharing options...
Ant Bennett Posted November 5, 2012 Author Share Posted November 5, 2012 poliss said: Check that the ends of the wires are clean. Link to comment Share on other sites More sharing options...
Ant Bennett Posted November 5, 2012 Author Share Posted November 5, 2012 Thanks Poliss. I have wired directly from the Select outputs to the inputs of the accessory decoders usinf new wire. Neither is responding to any addresses that were previously programmed using the Select. If I try to reprogramme the addresses for each then the led just flashes 3 times. Link to comment Share on other sites More sharing options...
Fishmanoz Posted November 6, 2012 Share Posted November 6, 2012 Have you tried with each of the non-responsive decoders being the only thing connected to the Select? If so, you may have faulty decoders. Is anyone aware of Hornby having had a bad batch of R8247s? Link to comment Share on other sites More sharing options...
St1ngr4y Posted November 8, 2012 Share Posted November 8, 2012 I had an issue recently, whereby one decoder kept losing its address, and I finally obtained a replacement from Hornby. However, the replacement is now doing the same, even though it is located in a different place on the layout and with a different address than the original faulty one. I use an Elite, and I have noticed that this decoder seems to lose its address if a short circuit occurs on the whole system. This sometimes occurs, for example, if any point fails to throw for whatever reason, and a loco fouls the electrofrog of the wrongly set point. Link to comment Share on other sites More sharing options...
Flashbang Posted November 9, 2012 Share Posted November 9, 2012 Hi Are you using a DCC bus pair of wires or just relying on the rails? If you have a bus pair for the power transfer consider adding to all ends of the bus wires a filter (Terminator) unit. Nothing more than a 150R resistor and a 0.01uF ceramic capacitor These will help remove transient spikes that appear on the bus when a short is created They should help stabilise the DCC data. If you want them ready made Bromsgrove Models was selling them, but for the cost of around £0.80p an end you can easily make your own. How to is shown on this website...http://www.brian-lambert.co.uk/DCC.htm#Basics Scroll down to the blue heading 'On very long bus wire runs' etc. Link to comment Share on other sites More sharing options...
Flashbang Posted November 9, 2012 Share Posted November 9, 2012 Sorry Typo the capacitor value should be 0.1uF Not 0.01 Link to comment Share on other sites More sharing options...
St1ngr4y Posted November 9, 2012 Share Posted November 9, 2012 Thanks for that Flashbang. I do have a bus which doesn't have any ends - it consists of two concentric circles. But why is it the same accessory decoder which loses its address? I have 12 other decoders which aren't affected when a short occurs. I was trying to further emphasise the question that Fishmanoz raised about a possible "bad batch of R8247s". Link to comment Share on other sites More sharing options...
Fishmanoz Posted November 9, 2012 Share Posted November 9, 2012 Thanks Stingray. Again, I think the decoder is faulty and you should return it. Link to comment Share on other sites More sharing options...
St1ngr4y Posted November 12, 2012 Share Posted November 12, 2012 I had already decided that a Hornby DCC Power Booster may be required, not for this particular problem, but because my layout is growing steadily in terms of accessory decoders connected, and DCC locos on the track, even though I never run more than 3 locos at once. And guess what..... After installing a Booster, the problem with the decoder losing its address when a short occurs, has disappeared. Maybe the electronic filter, described by Flashbang, is built in to the Power Booster?? Anyway the Power Booster is now installed, but I have two comments which I would like to make about it. 1. There are a few ways of connecting up the Power Booster, one of which involves using an RJ12 cable to connect it to the Xpressnet port on the Elite. However, Hornby don't provide such a cable (R8236) with the Booster. 2. If a short does occur when using the Booster, it is the Booster which handles it - the power to the layout is cut and a red overload light illuminates on the Booster. However, the only way to reset it having corrected the cause of the short, is to disconnect and reconnect the Booster from its power source. I would have thought an Escape button such as the Elite has, would have been appropriate. Link to comment Share on other sites More sharing options...
poliss Posted November 12, 2012 Share Posted November 12, 2012 How many locos did you have on the track? A DCC fitted loco consumes some power even when it isn't moving. Link to comment Share on other sites More sharing options...
St1ngr4y Posted November 13, 2012 Share Posted November 13, 2012 Currently I have 9 locos on the track, with a maximum of 3 running together at any one time .... which is why I decided to acquire a Power Booster. Link to comment Share on other sites More sharing options...
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