Hornby Accessory Decoder

[WandererReturns]

Am I correct in thinking the following. If the CV for output 1 on the Hornby Accessory Decoder is set to 513 then output 2 would be 514, output 3 would be 515 and output 4 would be 516 or would I have to do these CV's individually? 

Also regarding the Hornby Colour light signals and the Hornby Accessory Decoder am I correct in thinking whatever the CV setting is for the output which has the Hornby Colour Light Signal this would need to have the CV value set to 0 so that it has continuous output in order for the light signal to work correctly?

Many thanks,

Jon 

[Chrissaf]

Your assumptions are incorrect....you have misunderstood the R8247 'user guide'. Let me try to explain.

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This description assumes that you are using the Hornby Elite controller as a 'stand alone' controller. If you are not, using the Elite, then tell us which controller you are using. If you are using the Elite WITH RailMaster, then this description is not relevant, as configuring the R8247 using the RM interface simplifies the configuration immensely.

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So assuming the Elite, read on. If you are not using the Elite as a 'stand alone' controller, then tell me so that I can post revised guidance for the controller you are using.

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Background information.

To change the configuration of the R8247, it needs to be the ONLY device directly connected to your Elite 'Prog A&B' terminals.

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The Elite uses Group addressing with the R8247. Group numbering starts at 1 and goes up sequentially in ones [1, 2, 3 ,4 etc]. Each Group represents four ports such that:

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Group 1 = Port 1 = DCC Address 1 [First R8247]

Group 1 = Port 2 = DCC Address 2

Group 1 = Port 3 = DCC Address 3

Group 1 = Port 4 = DCC Address 4

 

Group 2 = Port 1 = DCC Address 5 [second R8247]

Group 2 = Port 2 = DCC Address 6

Group 2 = Port 3 = DCC Address 7

Group 2 = Port 4 = DCC Address 8

 

Group 3 = Port 1 = DCC Address 9 [Third R8247]

etc etc

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Now the Elite in 'stand alone' configuration mode only supports Groups up to 63 which equates to Port DCC Addresses 249 to 252

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The R8247 Accessory Decoder hardware however can support Groups up to 511 which equates to Port DCC Addresses up to 2,044. This means that to configure Groups 64 to 511 requires a different controller. Note that the reference to CV521/CV9 in the R8247 'user guide' is only applicable when trying to configure Group addresses higher than 63 i.e using a different controller. Note also, that if using RailMaster as the controller interface, that RM can configure all the addresses up to 2,044 even if using the Elite controller as the physical RM track interface.

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OK that is the background theory dealt with. This next section deals with how to apply this background theory to programming the R8247 using the Elite.

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First decide which block (Group) of four DCC addresses you want to configure. Bear in mind that out of the box, the R8247 is factory configured with Group 1 [DCC Port Addresses 1, 2, 3 & 4].

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So for the purpose of this description. I will assume that the Group addresses you want to configure is Group 2 [DCC Port Addresses 5, 6, 7 & 8] and will be assigned to a second R8247 Accessory Decoder.

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I won't reproduce the actual programming description ie. what buttons to press and knobs to twist as these instructions are adequately covered in the R8247 user guide. So the description that follows is focusing more on the configuration rationale. For the purposes of this quick tutorial, ignore the references to CV1 to CV9 in the R8247 'user guide' as they are not relevant. They can be optionally used instead of the CV5xx range

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Use the Elite controller to write value 2 (Group 2) to CV513 (see the R8247 user guide regarding how to do this).

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This will configure Port 1 as DCC Address 5. This will also automatically address Ports 2 to 4 as DCC Addresses 6 to 8 respectively.

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By default, all the four Ports will be configured for Pulse operation, with a pulse length of 100 msec (milliseconds).

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If being used for Solenoid point motors then this is the preferred configuration setting.

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However, if you want one or more of the four ports to be 'always on' for example to operate two aspect bulb/LED based signals then you need to modify the values of CV515 to CV518 as appropriate to change the default 1 value [100 msec] to zero [Always On].

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CV515 = Port 1 = 1 [default 100 msec] OR = 0 [Always On].

CV516 = Port 2 = 1 [default 100 msec] OR = 0 [Always On].

CV517 = Port 3 = 1 [default 100 msec] OR = 0 [Always On].

CV518 = Port 4 = 1 [default 100 msec] OR = 0 [Always On].

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Does this now clarify your understanding of the configuration information contained in the R8247 'user guide'

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TIP: As this is your first post, just be aware that the 'Blue Button with the White Arrow' is not a 'Reply to this post' button. If you want to reply, 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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[WandererReturns]

Thank you for getting back to me.

Yes I will be using a Hornby Elite. I have 44 points in total so I will be using Groups 1 - 11 for these. That's the straight forward bit as these won't need to be changed in anyway.

There will be 12 Hornby Colour Light Signals in total on the layout so these will use Groups 12-14.

The bit that's confussing me is regarding the CV for the coloured light signals.

Is this correct?

1. firstly use 513 and assign group required: eg: 12
2. to change the CV setting for output 1 i use 515 and then change the CV value for this output to 0

For all of the decoders will it be the same CV values 515,516,517 and 518 and then I just go into each of these individually changing the CV value to 0?

Apologies for the daft questions just trying to get my head round it all.

All the best,

Jon

[96RAF]

As you are under the Elite stand alone cutoff you can simply write your pulse time to CVs 3 to 6, which are effectively the same as CVs 515 to 518. This additional range was initialy introduced by NMRA to cater for the need for handling more accessories, then they changed their mind and made it optional. See here - scroll down to table 3 and subsequent text.

https://www.nmra.org/sites/default/files/standards/sandrp/pdf/s-9.2.2_decoder_cvs_2012.07.pdf

 

Most controllers require you to write group addresses for accessories but Hornby kit auto-converts a channel address to a group address for you.

[Chrissaf]

I explained everything in as much detail as I could in my first reply. I shall try again.......

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Yes I will be using a Hornby Elite. I have 44 points in total so I will be using Groups 1 - 11 for these. That's the straight forward bit as these won't need to be changed in anyway.

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If read as written, then that is not strictly true. If you have got 44 points and assuming that each point will have a dedicated R8247 port, thus 44 ports......then that equates to 11 x R8247s. Then 12 x Signals equates to a further 3 x R8247s making 14 x R8247s in total. Each of these 14 x R8247s will need to be configured differently and independently 'one at a time'. So it is not correct to say that they won't be changed in anyway, which is what you inferred in the phrasing of your written text.

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Note that where two points need to always throw together. For example a point cross-over between two loops. Then both point motors can be wired to the same R8247 port. This can save the number of R8247 ports you need to use, and potentially the number of R8247s you need to buy.

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So to reiterate my earlier reply, to try and give total clarity:

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All 14 of them 'out of the box' will have the SAME configuration. Port addresses 1 to 4 with 100 msec pulse operation. Only the first R8247 will not need to be changed, the other 13 will need to be reconfigured as below:

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• R8247 number 1 will be Group address 1 = Port addresses 1 to 4 (already configured as default)
• R8247 number 2 will be Group address 2 = Port addresses 5 to 8 (you need to configure this yourself)
• R8247 number 3 will be Group address 3 = Port addresses 9 to 12 (you need to configure this yourself)
• R8247 number 4 will be Group address 4 = Port addresses 13 to 16 (you need to configure this yourself)
• R8247 number 5 will be Group address 5 = Port addresses 17 to 20 (you need to configure this yourself)
• R8247 number 6 will be Group address 6 = Port addresses 21 to 24 (you need to configure this yourself)
• R8247 number 7 will be Group address 7 = Port addresses 25 to 28 (you need to configure this yourself)
• R8247 number 8 will be Group address 8 = Port addresses 29 to 32 (you need to configure this yourself)
• R8247 number 9 will be Group address 9 = Port addresses 33 to 36 (you need to configure this yourself)
• R8247 number 10 will be Group address 10 = Port addresses 37 to 40 (you need to configure this yourself)
• R8247 number 11 will be Group address 11 = Port addresses 41 to 44 (you need to configure this yourself)
• R8247 number 12 will be Group address 12 = Port addresses 45 to 48 (you need to configure this yourself)
• R8247 number 13 will be Group address 13 = Port addresses 49 to 52 (you need to configure this yourself)
• R8247 number 14 will be Group address 14 = Port addresses 53 to 56 (you need to configure this yourself)

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The Group numbers are ONLY relevant for the initial configuration task using the Elite. The Group numbers serve absolutely no purpose whatsoever when operating the R8247s. When you use your DCC controller to operate the R8247s you use the Port Addresses.......in your case Port Addresses 1 to 56 as listed above.

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Now if all 12 ports of the last three R8247s (12 to 14) are going to be used for signals and need to be configured for 'always on'.

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Then when you have each of these last three (independently, one at a time) connected to your Elite 'Prog A&B' output i.e when you are configuring their CV513 (optionally CV1) with the Group numbers 12 to 14 respectively. Then for each one of the three, you write:

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0 to CV515

0 to CV516

0 to CV517

0 to CV518

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This means having to repeat the same process three times for these last three R8247s with only the CV513 value changing for each of the three R8247s.

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Does this revised description now make sense?

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Addendum.

Now that you stated you will have 14 x R8247s. You may experience power issues. The R8247s internally have CDU capacitors. At switch on & power up, these may invoke a surge of charging current sufficient to trip the Elite controller. If this happens, then I would suggest buying a couple of Boosters (well one at the very least) and power the R8247s separately via the Booster. If you buy two Boosters, then have each powering 7 x R8247s.

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It is only the initial power up surge current that is likely to cause an issue. The ambient idle background current drawn by a R8247 is about 15mA, and drawing a surge of up to 130mA when a point motor is operated and the capacitors need to recharge. The recharging surge should not be too much of an issue providing you are not operating too many points simultaneously.

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