Railcom compatible equipment

[eventide01]

On 16/10/2020 at 18:43, Nigelcliffe said:

One possible route out would be to put the Cobalts on an accessory bus where the RailCom Cutout is absent.   Unfortunately, to do that requires more hardware adding to provide a bus without the cutout.  

 

- Nigel

 

I talked this option over with one of the suppliers but I have ruled it out as the frog wire in the Cobalt would then be on a non-railcom feed.  I'm not worried about losing railcom info for that small part of time, but I do think there will be issues where a loco bridges two track feeds, one which is railcom and one not, so there is a voltage gradient (and the two track supplies maybe out of sync with each other), particularly when packet activity is significant as the railcom cutout is per packet.   Using juicers on the railcom enabled feed instead of the Cobalt frog wire would solve this but kind of defeats the object of Cobalts, let alone the fact that it is even more hardware

 

I have come to the conclusion that Cobalts are likely incompatible with railcom on a busy DCC bus (as are other DCCConcepts products), but they probably aren't too bothered as railcom userbase is considerably smaller than non-railcom, even if it is growing, and it would cost them development expense to solve it.

 

It certainly isnt an iTrain problem either, as Cobalts were getting readdressed simply using the DR5000's own switchboard to simulate a busy set of turnouts firing simultaneously, if railcom was enabled.  The problem didnt arise with railcom off

 

I am replacing my cobalts with MP1s and it is a proper ballache and additional wiring, but they are also a lot quieter

 

 

Edited October 19, 2020 by eventide01

[Nigelcliffe]

2 minutes ago, eventide01 said:

 

I talked this option over with one of the suppliers but I have ruled it out as the frog wire in the Cobalt would then be on a non-railcom feed.  .....

 

 

 

Yes, I agree with that concern.   

But, that can be got-around by using the other set of contacts on the Cobalt to switch the frog - take power into the switch from the track DCC signal, and the output from the switch to the frog.   

 

That might be cheaper/easier than replacements.  

 

- Nigel

[WIMorrison]

The supplier was talking rubbish and clearly doesn't understand DCC wiring.

 

When you power the motors from an accessory bus you do not use the frog feed from the Cobalt motors and instead you use the SPDT switch that they include with the motor. You feed the track bus into each side of the SP{DT switch and the frog is fed from the common terminal.

[eventide01]

6 minutes ago, WIMorrison said:

The supplier was talking rubbish and clearly doesn't understand DCC wiring.

 

 

No, this is me who said I presently use the cobalt frog wire (but this would lead to the two different track voltages), and so me who you think clearly doesnt understand DCC wiring.  The DCC supplier didnt make any comment about where to power the frog from.  The whole benefit of Cobalts is the "3 wire does everything".  Having to run the accessory bus into the dcc slots and then the track bus into the spdt slots literally eliminates this benefit.  For me anyway.

Edited October 19, 2020 by eventide01

[WIMorrison]

I thought the statement was that the supplier had told you to use the frog wire , no matter if you use MP1 then you would wire them in exactly the same way by taking the feeds from the track bus and the frog from the common therefore changing gains you nothing.

 

FWIW I have 24 Cobalt IP Motors running on an Accessory bus that has Railcom on it and I don't have issues. I also power the frog using the SPDT switch on the Cobalts. I also have !8 (about to be 30 MP1s running as I describe)

[eventide01]

I agree an MP1 needs the additional wiring, but what it gains is I don't need a separate accessory bus and booster without the railcom cutout. I'm N gauge, and not as many motors as you, and I would prefer not to have one.  Maybe my Cobalts are faulty or maybe I have excessive track feed noise or ringing, but its absolutely clear that the motors get readdressed while in run mode and that's not ok for me under any circumstances.  The noise reduction is a welcome side benefit

[WIMorrison]

I would always create a separate accessory bus, useful to have - even using iTrain  

[Crosland]

On 16/10/2020 at 18:48, WIMorrison said:

can the Sprog sniff the main bus to relay the commands without railcom?

 

No.

 

If there were enough interest it would perhaps be a possibility for our SBOOST booster, but I'm too busy at the moment to even think about it

 

[DCCconcepts]

Apart from having to sometimes disable Railcom whilst addressing Cobalt Digital IP, we have found that there are no other issues running them with Railcom enabled systems.

 

With the close co-operation of DCC Train Automation (UK distributor of iTrain and Digikeijs), the above issue (multiple motors on a route) has been tracked to the trip settings within the DR5000 being set too low.

 

The trip timer setting needs to be increased with Railcom on, compared to Railcom off. (250ms seems to be an acceptable value)

 

Also using a slight delay between individual point commands when a route is selected can help.

 

Best Regards.

The DCCconcepts Team

 

 

 

 

 

 

 

 

 

Edited October 24, 2020 by DCCconcepts