DCC decoders that support the optional Decoder Automatic Stopping Configuration,

[BullDog pkl]

Do Hornby DCC decoders support the optional Decoder Automatic Stopping Configuration (ABC)

[5Dublo2]

The standard Hornby (8, 6 and 4 Pin) Decoders are extremely basic and haven't changed design in some time. As such it is unlikely the have support for a feature that is relatively new extension to the NMRA standards for DCC

This is manual (leaflet) for one of the Hornby decoders which shows the limited supported CVs

https://support.hornby.com/hc/en-gb/article_attachments/360015928340/R8249-Locomotive-Decoder-Leaflet.pdf

Not sure about the Hornby (8-Pin) TTS decoders as they are more advanced, although gut feeling says that ABC won't be supported by these either.

Note: Hornby's 21-Pin decoders, if/when they are available may have more advanced capabilities.

[96RAF]

As Colin says the Hornby R8249 series (4/6/8-pin) decoders are too basic to support ABC/ADCC, nor do TTS decoders as they are R8249 based. The old R8245 Sapphire decoder does support auto stop, but these are getting to be difficult to find.

Hornby new decoders when launched will support auto stop amongst other advanced features.

Failing that you will have to look at decoders from Lenz or Zimo, etc.

[ColinB]

I bought one of those circuits off LaisDCC that is meant to lower the voltage so the trains stop, but it failed to work with any of my Zimo decoders. So it could have been the circuit or the decoder at fault.

[96RAF]

The ABC module is a simple 5 diode loop with the live-isolated track section connected either side of one diode to give a four by one offset of the DCC signal which the decoder sees as a positive or negative bias depending upon which rail is cut, when the appropriate CVs on the decoder have been set. Normally one CV sets the rail (left or right) and another CV sets the subsequent action (e.g. slow, stop or wait).

Images credit Hornby Hobbies

[mjb1961]

You need a hornby sapphire decoder.

[96RAF]

You need a hornby sapphire decoder.

 

 

I already said that last Wednesday...

The old R8245 Sapphire decoder does support auto stop, but these are getting to be difficult to find.

[ColinB]

Thanks 96RAF for the circuit. I spent ages looking at my LaisDCC PCB trying to work out whether the little smds were resistors or diodes. Now I know what it does I can see if they are working properly, by looking at the voltages across the diodes.

[96RAF]

Thanks 96RAF for the circuit. I spent ages looking at my LaisDCC PCB trying to work out whether the little smds were resistors or diodes. Now I know what it does I can see if they are working properly, by looking at the voltages across the diodes.

 

 

You can bash them out for pennies Colin. But you also have to set the decoder up.

[Deem]

Is this the same function everyone talking or something else?

Regards

[96RAF]

Have a read of this (ABC)

https://www.keymodelworld.com/article/automatic-braking-control

and this (ADCC)

https://tonystrains.com/news/lenz-asymmetrical-dcc-and-abc/

and the Wiki

https://dccwiki.com/Automatic_Brake_Control

[Deem]

Thanks for detailed info, good read. 96RAAF

Regards