Fiddle Yard Shuffle?

[johndon]

This may end up being a computer control topic rather than a DCC question per-se but I figured I'd ask here first...

 

I'm involved with a large layout, controlled via NCE Power Cabs (wireless) that has a 14 road fiddle yard that is around 20' long.  Each road in the fiddle yard has at least 2 trains in it and route selection through the fiddle yard is through JMRI via MERG CBUS.

 

Question is, when a train leaves a fiddle yard road, is there a way to automatically move the train behind it up to the end of the road filling the space left by the departed train so there is a gap behind it for the departed train to return to once it had completed it's lap round the layout?

 

John

 

 

[WIMorrison]

I think you need to ask this question on a JMRI forum and not RMWeb

[johndon]

5 minutes ago, WIMorrison said:

I think you need to ask this question on a JMRI forum and not RMWeb

 

You'll have to pardon my ignorance but why?

 

As I mentioned the JMRI is used for route selection (i.e. turnout control) through the fiddle yard via MERG which is a completely separate system from the DCC control of the trains...

[WIMorrison]

Because it would be JMRI that you would use to shift the trains, using its computer control capabilities 

[johndon]

Ah, OK, so JMRI could, potentially, be used to shuffle the trains automatically whilst the NCE system was used, at the same time, to 'drive' the other trains?

Edited November 25, 2021 by johndon

[WIMorrison]

 

[johndon]

Thank you, I'll head over to a JMRI forum

 

[Nigelcliffe]

In the general case, its really tricky to do.   You need to know the address of the train at the back of each road (which changes depending which train it is).  And then the system controls that train to move it forwards.     

Because you're using an NCE system, you can't use RailCom to identify the locomotives, so identification has to be another way (RFID might work as an option, just prior to entry to the fiddle yard).   If you have really good train tracking through the layout, then you could work from the starting positions and use JMRI to track the trains around the layout, so knows which train is where, but that depends on the amount of block-detection you have in place and its reliability. 

 

 

There is a specific case which is simpler;  if all decoders support Asymmetric DCC Braking (ABC - that means ESU, Zimo, Lenz, and a handful of others).  Then could use ABC brake modules to stop the train because the block ahead is occupied, and then release them to move forwards and stop them again.    To use it, the operators don't stop the trains, but just let them run into the fiddle yard and rely on the ABC braking to stop them at the correct places.       

 

 

 

- Nigel

Edited November 26, 2021 by Nigelcliffe

[Gordon A]

Look at Clutton. Tim Venton devised a system for automatically moving trains up in a storage yard loop.

All the locos in one loop were programmed with the same number, which in Clutton's case was the number of the loop.

Realistic top speeds were programmed in the locomotive's chip. This meant that when operating storage loops with more than one train, the departing train was driven at full speed out, which gave enough power for the remaining trains to shuffle up.

I think Tim used JMRI for the route selection.