Can HM7000 be run alongside traditional DCC?

[Kim-344602]

I have been "playing trains" for more years than I care to divulge. (But it started when 3 rail HD was still sold) However, I am still trying to get my head around digital and the new system.

I understand that whilst a DCC fitted loco can run on DC and a DC can be controlled by a DCC controller that neither is recommended. However, can DCC be run on the same tracks as HM7000 at the same time? From my understanding, the power supply to the track can come from a DCC controller whilst using the app to control an HM7000 model. But if you have a traditional DCC fitted loco on the same track, can that still be controlled independently and at the same time using the controller as using the app to operate the HM7000? Or will they interfere with each other?

[96RAF]

App control can as you say use DCC power on the tracks as it’s approved power source.

App control is over the air whilst DCC control is through the rails, therefore you can control your HM7000 decoders from the app and control your regular decoders from your DCC controller - absolutely safe and the one will not interfered with the other.

[Kim-344602]

App control can as you say use DCC power on the tracks as it’s approved power source.

App control is over the air whilst DCC control is through the rails, therefore you can control your HM7000 decoders from the app and control your regular decoders from your DCC controller - absolutely safe and the one will not interfered with the other.

 

 

Many thanks, that helps a lot.

One more question. I have quite a few "legacy" models which will not run on DCC for a variety of reasons such as coreless motors in finescale kits and some with live chassis. I have always used a system of cab control so that any circuit or any portion of the track can be controlled by any controller. The intention would be for one of those to be DCC so I can run both. Now in a usual cab control system, there is a common return with only the power feed being switched and the return all on a return bus. Would that work with DCC or will I need to switch the return as well as the live feeds?

[96RAF]

With DCC all of the track is made live. Previously sectioned D.C. tracks normally do this by throwing all the section switches to on. I wouldn’t like to say yes definitely without seeing a sketch of your cab control wiring. Draw it up rough and ready, take a photo and post it here, although it will have to be released by a moderator before it pops up in the thread.

What you mustn’t do is mix DC with DCC so the common return would need breaking into. The other no-no is do not use the output from the analogue controller to power the track the HM7K decoder is using - see the sticky post about approved power supplies.

[ColinB]

I see what you are trying to do, I can now see why I have so many issues getting a suitable switched circuit board, all of them only switch one wire. My DCC layout is split into sections, it makes fault analysis easier and is a carry over from when it was DC. I have always switched both wires because lets face it when you run in reverse the wires are switched round. So what you will need to do is rewire it so that both wires are switched. It might work switching just one wire, but I am not sure. You might find though you get some really funny effects.

Thinking it about it a bit more I think it will work switching just the one wire as this is effectively what I do with my points. I have isolating sections after each turnout so that if the point is set wrong and the loco approaches from the wrong direction, the loco stops but I am only switching one side of the DCC the other track isn't effected.

[ntpntpntp]

I've always cut both rails in my cab control sections and use double pole switching for each section. I avoid common return, thus ensuring I can use any type of DC controller for each "cab" HOWEVER I wouldn't mix DC and DCC on different cabs, the risk is too great of something accidentally bridging the two systems. DCC systems hate other power sources trying to feed into their output electronics and it can blow the DCC's output.

One other comment on your original post: Running a DC loco on a DCC system's "zero stretching" capability is now considered a big no-no for small scale motors especially coreless types. You can run a DCC fitted loco on DC unless that ability has been turned off in the decoder. Pure smooth DC is recommended, as PWM power can confuse some decoders and in addition feedback controllers cannot read the motor back-EMF so they over-compensate which results in poor running (there are horror stories of decoders being killed by PWM feedback controllers though I don't know how true that is).

[Chris-372862]

Yes, I have a Heljan 33 with Hornby dcc chip on inside track controlled by Hornby elite and a Hornby 50 controlled by hm7000 on my phone on the outside. There’s no interference and the whole thing works well

[96RAF]

Yes, I have a Heljan 33 with Hornby dcc chip on inside track controlled by Hornby elite and a Hornby 50 controlled by hm7000 on my phone on the outside. There’s no interference and the whole thing works well

 

 

In that case if you simply power all the layout from the Elite track output you can run either loco on either track under their own control method.