One of my trains starts moving when I connect accessory decoder to track

[ParkyTrain]

Hi, I have just changed over to digital. Have 3 trains running with addresses 1,2 and 3. They work fine until I then add accessory decoder for point motor. With decoder connected to track for power one of the trains then starts moving on its own. If I take this train off the other two work fine and the point works fine. When I put the 3rd train back it starts going again, disconnect the decoder from track and it works fine from the control as it should. As soon as I connect the decoder again it starts moving. Can anyone advise on this, have I done something wrong?? Thanks.

[NormanQ4]

Change the number 3 to another number because this is the default decoder number. All locos come set at number3.

[ParkyTrain]

Change the number 3 to another number because this is the default decoder number. All locos come set at number3.

Hi NormanQ4, Thanks but still got the problem. Am now using addresses 1, 2 and 4. The same engine whatever address number it uses starts moving along (very slow) as soon as the decoder is connected to the track.Would this be a problem with the engine itself?

 

 

 

 

[Chrissaf]

Is the train that moves the one with the 3 address?

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As Norman says, this is the default address for all manufacturers loco decoders and should be avoided in use on the layout. That said, it shouldn't in theory interact with the accessory decoder either.

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Is it just a single accessory decoder with the default 'out of the box' port address of 1 to 4 you have installed (assuming a Hornby R8247 decoder)?

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Also, what controller do you have Select, e-link or Elite (again assuming Hornby)?

[NormanQ4]

I had the same e problem a few days ago. You may find that the loco I'd is changing back once its finished reading the CV,s check CV 1 is still set to the number you gave it. If not then change it.

[ParkyTrain]

Is the train that moves the one with the 3 address?

.

As Norman says, this is the default address for all manufacturers loco decoders and should be avoided in use on the layout. That said, it shouldn't in theory interact with the accessory decoder either.

.

Is it just a single accessory decoder with the default 'out of the box' port address of 1 to 4 you have installed (assuming a Hornby R8247 decoder)?

.

Also, what controller do you have Select, e-link or Elite (again assuming Hornby)?

Hi,

Not using address 3 now. Train that moves is the same Train whichever adress I give it. Works fine when decoder (which is the R8247) not connected to track. As soon as decoder connected to track this train starts moving. If I remove the train I can connect decoder again and the point work fine along with the other two trains. I am using the Select Hornby.

As this engine is the only one that seems to have an issue Im thinking the engine has the problem?

Thanks.

 

 

 

[ParkyTrain]

I had the same e problem a few days ago. You may find that the loco I'd is changing back once its finished reading the CV,s check CV 1 is still set to the number you gave it. If not then change it.

Hi,

The train address stays as it has been set.

 

 

 

 

[Flashbang]

He cant check CV1 as his DCC is a Select!  This is not able to read CVs.

I would initially try giving the problem loco a much higher address number e.g.  say 44 or even 56 etc (bearing in mind the Select can only allocate address numbers 1 to 59)  then see if it still moves on its own after ensuring the speed setting for that address number is set at zero.  Don't forget that if  a speed setting has been allocated to a decoder it will keep doing that speed until it receives a new instruction to do something else speed wise.

You may like to try a Select reset which may cure the problem. See the manual page 19 on how to do this.

Next if the none of the above cures the problem, do you know anyone who has a better DCC system? I would then try doing a decoder reset with CV8 entering 8 to reset the decoder which may cure the problem.

After that consider replacing the decoder.

[NormanQ4]

Have you programmed the acc. Decoder on the programming track before connecting it to the main track.

[Chrissaf]

Yes it is a pity that you have the Select controller. This controller has limited functionality and eliminates several options that you would have had open to you with a higher specification controller. For example performing loco decoder factory resets (writing value 8 to CV8) , reading CV's etc.

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All I can suggest is to concur with Norman. Re-programme your R8247 Accessory Decoder on the Select programming output. I'm assuming here that you have just used it with the default settings straight out of the box. This will have set the port address as 1 - 4. If the R8247 Accessory Decoder is still configured as factory default, this could very well be the root of your problem. With the Select, R8247 Accessory Decoder port addresses need to start at 61. See the R8247 Accessory Decoder instruction sheet that came with it for details.

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If your R8247 Accessory Decoder is already programmed with addresses in the 61+ range, then the likelyhood there is an issue with the decoder in the affected loco, and since you can't perform a loco decoder reset with the Select controller (do you know anybody with a higher specification controller that could do a loco decoder reset for you). Then your only option is to either replace the decoder or have a service centre look at it.

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But first, as Flashbang suggested perform a Select reset as per page 19 of the Select manual.

[Cronan]

Why is everybody saying the select is at fault surely its the decoder. Parky, maybe swap the decoder with another from another loco then you might see if the decoder is at fault.

[ParkyTrain]

Why is everybody saying the select is at fault surely its the decoder. Parky, maybe swap the decoder with another from another loco then you might see if the decoder is at fault.

Hi Cronan,

As the train was new yesterday I called the shop and went and swapped it over. I am pleased to say problem resolved so looks like it was a problem with the train itself and probably the decoder.

Thanks to all for your help and suggestions.