The Hornby R8245 Sapphire Decoder has a facility to create an “AI” (Artificial Intelligence) train which will run to and fro automatically without the need for any switches or sensors on the track.

R8245 is for DCC (Digital Command Control) users only.

Programming the auto-control cycle on the Hornby R8245
Sapphire Decoder

The FIRST thing you need to know is that CV 140 turns the Auto control Cycle ON or OFF.

The SECOND thing you need to know is the value to write to CV140.

The only value you need to remember is 12. Think of the 12 Days of Christmas!

The THIRD thing you need to know is the value to write to CV140 to
turn off auto control.

This is easy to remember:  It is a zero, zadda, zilch, nothing.

Now you have understood those basic things – writing 12 to CV 140 turns on auto control and writing a zero turns it off.

You can now enter the values needed for duration and speed..

In this example we are going to prorgramme an auto control cycle which
will make the train run for 30 seconds in one direction and then run back for 30 seconds at the same speed.

To wait initially for 5 seconds, write 5 to CV123
To travel forward for 10 seconds, write 10 to CV127
To set a speed of 20, write 20 to CV124

Now, having programmed the outward journey, you must
programme the return trip!
To wait at the station for 10 seconds, write 10 to CV131
To set reverse speed of 20, write 20 plus 128, (which makes 148) to CV132

To set a duration of 30 seconds for the return trip,
write the value 30 to CV135

And finally, to wait 5 seconds at your first station, write 5 to

That’s it!

The auto control cycle is now programmed. You can now
write 12 to CV 140 to the decoder to get the train going
by itself.

Things to remember!
Only set a slow speed and a short duration initially – once
the loco is under auto control, your DCC command station
cannot control it until a zero is written to CV 140.

An easy way to programme the Sapphire decoder is to use
Decoder Pro which is a part of JMRI

However you can programme the Sapphire decoder with
any DCC system.



If you are using Dynamis, move the joystick left or right to
find the loco with the Sapphire Decoder

On Dynamis, having selected your loco, press the fourth button, it will
say ‘Edit Name’Move the joystick until it says ‘PROGRAM. Press the 4th
button again. It will say WRITE ADDR ON MAINTRACK. Move the joystick