Hornby R8247 point decoder

[gavco]

guys

I was wondering if someone can help me out as i have a little problem with my Hornby R8247 point decoder  as in useing the elink controler with railemarster software ?

Its ony just started hampering every time i connect the decoder to my track bus line i keep getting a on the 

Error message on the screen an the light on the elink keeps flashing 

 Telling me i have a short somewhere i have disconnected all the points so it must in the decoder it self  i was wondering if the is someway i can do or reset it or something? 

So i wondering if someone  has had this problem  as well an can help me out ?

I really look forward to hearing from you 

Gavin

From Australia

[RDS]

Hi Gavin

I have removed the duplicate post you entered in another thread, as a post in one thread only should be enough to get you some help.

 

I am sure that someone will be along soon to provide some advice.

[Chrissaf]

How to reset a R8247 using RailMaster is described in my 4th post down in this previous existing thread.

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

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Note however, that if the R8247 is faulty and is indeed presenting a 'short circuit' on the TRACK A&B terminals, then a reset is not going to work.

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Remember when reading my 'How To'...... the R8247 being reset is connected in isolation to your eLink PROG A&B output and not the TRACK A&B output, thus any 'short circuit' the R8247 is producing is unlikely to register on the eLink / RailMaster TRACK connection short circuit detection process.

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If you have access to a multi-meter, put it on the 'Resistance' scale and take a reading across the R8247 TRACK A&B terminals with the R8247 completely disconnected from anything else to see if you can measure a physical short circuit..

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Disconnecting your solenoid point motor wiring is very unlikely to have any effect whatsoever on a 'short circuit' detected by eLink / RailMaster as RM is not monitoring that wiring via the R8247. It can however detect short circuits created internally within the R8247 due to damaged output components....see next text section below.

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I notice in your other post that you may have set one or more ports on your R8247 to 'always on'. Be aware that the constant current that an 'always on' port can provide is extremely limited. Ideally anything you connect to it should not try and draw more than 120mA**. Now if you have connected something that requires a higher current, then it may be this that has burnt out the output semiconductors for that particular port. Now this would potentially make the R8247 present a 'short circuit' to eLink / RailMaster. If this is indeed what has happened, then the R8247 will need replacing with a new one as it probably won't be worth sending it back to the UK from AUS for repair.

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You will also need to review what the current draw of the accessory you attached to the affected port and take action to reduce the current it requires from the R8247. Perhaps using the R8247 port to switch a low current relay, which in turn switches an external higher current power source to your accessory.

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Note** The R8247 has a total max current source of 240mA shared across all four ports. This means that if all four ports are configured for 'always on' then each port individually should not exceed 60mA MAX. My recommended 120mA figure assumes a single port of the four is 'always on' and that the attached accessory circuit is designed to a 50% current utilisation, to minimise the electrical stress on the R8247 internal components. The Hornby 240mA figure is a MAX not a norm.

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Just to reiterate, just in case there is any misunderstanding. You do not use an 'always on' port to operate a Solenoid based point motor. Solenoid point motors must be operated with a 'pulse' that in most situations does not exceed 100 milliseconds. Also, to extend this 'pulse' length to seconds with a Solenoid motor attached can also damage internal R8247 components as the Solenoid coil presents a near 'short circuit' resistance to the R8247 port...typically 4 to 12 ohms. The outputs of the R8247 are (unfortunately) not 'short circuit' protected, hence why the operating pulses must be brief.

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TIP: As a relatively newbie poster on the forum, just be aware that the 'Blue Button with the White Arrow' is not a 'Reply to this post' button. If you want to reply to any of the posts, scroll down and write your reply in the reply text box at the bottom of the page and click the Green 'Reply' button.

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See also – further TIPs on how to get the best user experience from this forum.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

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[96RAF]

I seem to remember a very similar post recently but I cannot locate it. In the end from memory it was crossed droppers feeding the R8247 from the track bus.

[96RAF]

I found it here...

same Gavin

https://www.rmweb.co.uk/community/index.php?/topic/152632-hornby-r8247-point-decoder/

[gavco]

hi Chrissaf

Thank you for your reply as i relay as  appreciate your help

 an yes regarding the point decoder i thank i have stuffed it unforley

may be yoiu can help me out as its overs i going to require new point decoder as i was thinking there may be other options other the then to r8247 accessory decode to suit my lay ot ?

if you have any in mind id realy appreciate your feedback

one agane thank you

Gavin

[Chrissaf]

Gavin,

This is a Hornby forum and there is Hornby forum rule against actively promoting other branded products that compete directly with Hornby ones. So even if I had a product in mind that was the 'best thing since sliced bread' I am not allowed to tell you.......sorry.

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Hornby Forum Rules extract

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As a general comment....I can tell you that all the other branded Accessory Decoders are all compatible with RailMaster and that by far the majority of them are 'self learning' decoders which makes them a doddle to configure. Many of them also have additional features that far exceed the features on the R8247, such as 'manual override' and 'internal relay contacts' for operating scenic accessories and powering electrofrogs. You will need to do your own research as to which decoder is likely to meet your technical and operational criteria.

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As you are located in Australia you happen to have within your own country an accessory decoder manufacturer that is well respected by users. Take this as a hint.