DCC Handover

[Ray H]

I'm trying to establish whether there is a way to pass a stationary (dcc fitted) loco from one throttle to the other.

 

Basically Operator 1 wants to set a sound equipped train moving towards a stop signal. There will be an ABC braking section approaching the signal which will be active if the signal aspect is red/danger. Operator 1 then wishes to be able to do other things. The loco can't be transferred to Operator 2 at that time because Operator 2 is doing something else.

 

In due course Operator 2 will change the signal to proceed and unless Operator 1 has actually reset the loco's speed to zero once it has stopped at the signal, the loco will move forward still under the control of Operator 1 who is busy doing other things. If Operator 2 then selects the loco it will stop almost immediately and the sound will probably cease.

 

Is there any way that this unwanted stop can be avoided when Operator 2 tries to assume control of the loco?

 

This is a garden based layout so distances are longer than usual and the control system is an NCE PowerCab derivative

[Nigelcliffe]

 

Most DCC systems of reasonable capability will support hand-over of a loco at its current running speed, and with the functions still operating as set by the first operator.   So, either a system setting needs changing, or you'll have to upgrade your system.

 

- Nigel

[JimFin]

Operator 2 should simply call up the loco address, see it with zero speed and give it whatever instruction is appropriate. If operator one left it moving, that it should show up on controller 2 when the loco address was interrogated.

[Oldddudders]

On my Digitrax system, if I call up a loco already on another throttle, I will be asked if I wish to "steal?" Press Y and off we go. 

[Ray H]

The PowerCab allows one throttle operator to transfer the control of a loco to another throttle operator retaining speed and function settings. In fact what happens is that throttle 1 transfers loco A to throttle 2. In return throttle 2 automatically transfers loco B to throttle 1 - they basically swap locos they are controlling. Note Throttle 2 has no physical say in this swap, any agreement to the transfer is done vocally.

 

That's fine because throttle 2 gets the loco they're ready to control of and throttle 1 simply disregards the loco that came from throttle 2 and selects another loco (because the one they were controlling has gone and they were going to have to select a different loco anyway).

 

The situation that we would find ourselves in is that throttle 1 has driven loco A towards the red signal where the ABC braking section will cause loco A to stop - all its speed settings and functions remain unchanged so that the loco resumes when the signal changes to proceed. Note once throttle 1 has set loco A moving throttle 1 can forget that loco completely in the knowledge that the red signal will stop the train.

 

Throttle 1 will then start operating at least one further loco  - loco B etc - and no longer has any interest in loco A which will eventually come to a stand (or its control will be assumed by throttle 2).

 

Meanwhile throttle 2 is operating loco C in the knowledge that loco A will come to a stand at the red signal and not move forward until the relevant signal is changed. Eventually throttle 2 will be ready to allow loco A to move forward (by changing the signal). At this point throttle 2 has no control of loco A whose settings are still as set by throttle 1 where the loco is effectively on throttle 1's recall stack.

 

The moment that throttle 2 attempts to select loco A (and presses the Enter key), the loco will come to a stand with all its functions turned off (including sound).

 

What we haven't tried yet is what happens if loco A is already on throttle 2's recall stack from whence it could be recalled without having to press the Enter key.

 

There may be other options available with the NCE system but we're not aware of them.

[Ray H]

13 minutes ago, Oldddudders said:

On my Digitrax system, if I call up a loco already on another throttle, I will be asked if I wish to "steal?" Press Y and off we go. 

 

That would be exactly what we want if it is possible with the NCE system. At the moment the NCE system seems to work the opposite way to the Digitrax system where a NCE controlled loco is sent to another throttle and not taken by another throttle.

 

Alas there's far too much NCE kit involved to consider changing just for this feature.

[Nigelcliffe]

I think there is a setting which influences this handover - whether the functions and speed are reset.  I dont think its just limited by what's in the "recall stack",  though using the stack might be one way around it.  
NCE's documentation isn't that clear - there is a hint of it in the V1.65 upgrade notes.  I don't have an NCE system to hand (nearest is out-of-bounds on lock-down rules), and I can't be bothered to spend an hour googling for clues. 

 

[Ray H]

1 minute ago, Nigelcliffe said:

I think there is a setting which influences this handover - whether the functions and speed are reset.  I dont think its just limited by what's in the "recall stack",  though using the stack might be one way around it.  
NCE's documentation isn't that clear - there is a hint of it in the V1.65 upgrade notes.  I don't have an NCE system to hand (nearest is out-of-bounds on lock-down rules), and I can't be bothered to spend an hour googling for clues. 

 

 

Thanks Nigel.

 

Like you some of the things that might prove useful - a ProCab manual instead of my domestic PowerCab manual - are also locked away elsewhere.

 

However, I've just been re-reading the PowerCab manual and (think) I've centred on the feature you've mentioned which I'll experiment with at home a little later to see if it provides what we want.  That said, I don't know whether it is throttle or overall system set but I can play around with that on my OO layout where I have two ProCabs & PowerCab and an SB5 but no ABC braking module (but that doesn't matter because all we're trying to do is to retain speed & function settings).

 

It might be worth making the change to the system at the club as well once we can go there again if it works.

 

I'll report back.

 

Thanks

[Pete the Elaner]

 

7 hours ago, Oldddudders said:

On my Digitrax system, if I call up a loco already on another throttle, I will be asked if I wish to "steal?" Press Y and off we go. 

 

I have just tried stealing a loco in this way with a throttle on my ProCab.

PowerPro does not have the option to turn off SetLocoRefresh, so selecting a loco not already in the stack resets everything to zero. This is also true if the throttle is 'stealing' it.

If it is already in the recall stack, both throttles act as if they are in control.

Starting with everything off & the same loco selected on both throttles, I turn on sound with throttle 1 then start to drive the train.

If I then sound the whistle with throttle 2, this will turn sound off.

 

If you have SetLocoRefresh disabled (according to an addenum sheet, introduced with PowerCab v1.28b), it may well react differently.

I also have manuals for both PowerCab & PowerPro available so should be able to look things like this up (if I can find them in there ).

[Ray H]

I've got no documentation about the Set Loco Refresh in my manual - at least I can't find it if it is there. I would welcome an indication of what that facility is supposed to do if that's possible please.

 

I have now tried activating the function reset and that does seem to provide what we'll need. There is however, a brief time < second when the sound is interrupted as the second throttle takes control. It does appear that it only needs doing on one throttle where several are in use.

 

I was trying to break it by setting a loco moving with one throttle then selecting another loco with the same throttle (without changing any settings of the first loco). I then selected the loco with the second throttle and apart from the brief sound blip it appeared that the loco's speed remained as initially set until the second throttle changed the speed. What I ended up with was two throttles with both 6 loco recall stacks full of the same loco! Maybe that was influencing what was happening especially as some of the recall stack entries had different speed settings in different directions.