JMRI with R8427 Accessory Decoder

[Artificer1]

Hi, 

Can  someone please give me some guidance on how to programme the Hornby R8427 4 way accessory controller using JMRI for turnout control.
 

Thank you 

[Nigelcliffe]

There isn't a decoder file written for it, so ...

 

a - manually. Connect to programming track, use single-CV programmer.  

 

b - write your own file.  A quick scan of the manual suggests it adopts a fairly common CV structure for the basic elements, but there are a pile of complex options available.   So, the simple stuff could be done by editing a similar file (eg. the MERG accessory decoder is similar at a basic level).   If you get this to work, the should really contribute it back to JMRI for others to use in future.  

 

Once programmed, it should work like any other accessory decoder, send turnout commands to its address to operate.  

 

- Nigel

[RAF96]

Further complicated by the v2.0 R8247 having standard and two x special modes, which allow much more complexity of use and hence setup. Standard mode is simply the same as the v1.0 variant, four channels, two ports per channel and choice of pulse length or always on.

 

Such things can be set up in v2.0 as:

Group firing where one point will cascade fire one, two or three other ports.

Firing both ports in tandem.

Number and length of pulses.

Firing either/both ports of a channel, which requires allocation of 8 addresses to a four channel R8247. This can lead to complications if the addressing of adjacent R8247s does not take account of the expanded addressing.

 

The v2.0 manual is on the Hornby site for download, but I am happy to work with anyone who wishes to write the JMRI ‘file’ if they need help in understanding the scope of the new features. I wouldn’t have a clue about writing JMRI definition files myself.