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Discussion Starter · #1 ·
Hello

Currently I usually use locos running on separate DC and DCC. Now there are several types of loco, the seller says can run on both DC and DCC. So every time I change the DC mode to DCC or DCC to DC, does the jumper decode again or just let the layout run ? So what will the loco address selection when running on DCC?
Example:
1. Roco BLS Electric Locomotive 63882 HO Scale DCC. According to the seller, it has decoded to running on DCC. When running on DC, we have to remove the cover and jumper back to DC mode.
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2. Roco 63840 11128 Electric Locomotive Re 4/4 SBB DC/DCC. According to the seller, it runs on both DC/DCC but there is no information on how it will work when changing from DC to DCC and DCC to DC

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Most modern decoders are 'dual mode', meaning they'll run on either DC or DCC. You can only apply one type of power to the rails at a time. NEVER both types at once.

Decoders configured to NMRA conventions will be able to set CV29 for either dual mode or single mode. If dual mode, CV29 must have a computed value applied to it per an online calculator that makes a specific locomotive run forward in one direction, and the lighting should match. If single mode, it will only be in DCC.

Decoders with factory defaults will only have Add '3' or '03". However, even dual mode decoders can have any address programmed. On DC ops, the decoder won't apply an address as it won't have one in DC. When/if you switch to DCC, it will respond only to the active address programmed into it. So, in DC, address won't matter. Your locomotive will operate as other DC locomotives. If you switch to DCC, the decoder will 'listen' to packets with instructions coded for whatever address you assign to it. If you leave it at the default of '3', it will only act when you have 3 active on your throttle. If you programme an Add of '235', it won't do anything until you acquire 235 as an active address.

You will have to investigate whether the decoder you are using is 'dual mode'. Apparently yes, but you should verify, and probably get a manual at the website.
 

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I'm wondering if the engines the OP describes are like some of the older Atlas locos, the earliest ones to get factory-installed dcc.

These have a lightboard/motherboard with a physical "jumper" on them.
To switch from DC to dcc you have to physically "move" the jumper from one set of pins, to the other.

It's possible that older Roco engines had these, as well.
I -think- the OEM manufacturer of the boards was Lenz -- they were European, right?
 

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Cycleops! Been quite awhile since I've heard from you! To the OP, its always dangerous to try and run a layout with both DCC and DC. Switching from DC to DCC and forgetting to remove a DC or change jumpers to DCC can ruin your DC locomotive. Pick one and stick to it, much safer!
 

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I should run either one or the other. Using both is of course possible but sticking to one can avoid any expensive mistakes.
Welcome back, my friend! We've missed you!!

For the OP... you keep getting the same advice, going quiet for a month or two, then coming back with a slightly rephrased version of the same question. Then answer isn't changing: chose a control scheme and stick with it.
 
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Discussion Starter · #8 ·
Welcome back, my friend! We've missed you!!

For the OP... you keep getting the same advice, going quiet for a month or two, then coming back with a slightly rephrased version of the same question. Then answer isn't changing: chose a control scheme and stick with it.
Sorry. My previous question involved using 1 layout to run both DC and DCC. And here is a loco that can run DC and DCC because there are some old locos for sale on ebay. They write only: DC/DCC. I asked the seller:
One said: every time running on DC or DCC, you have to re-plug the corresponding jumper. OK, have to be careful if switching DC and DCC
Other said: just put it on and run. I haven't used this type of decode yet, so I'm just referencing everyone's experience
 

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I run a DC layout and have a few DCC locomotives, the only problems I've had were with sound. They run on the DC layout out of the box.
 

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Decoders made prior to about 2005 often had unique, and now dated, means of switching between DC and DCC operations. The QSI decoders, for example, had jumpers on the older models. Later, they only needed to be correctly configured in CV29. So, if the seller has replied and said it needs a jumper turned, you should probably heed that information. Maybe ask a couple more questions.
 

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Discussion Starter · #11 ·
I run a DC layout and have a few DCC locomotives, the only problems I've had were with sound. They run on the DC layout out of the box.
What's the difference between your DC and DCC layout? I use the same layout. When running the DC locos I use a DC controller. When running DCC locos I replace it with DCC controller. Do not run both DC and DCC at the same time on the same layout
 

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What's the difference between your DC and DCC layout? I use the same layout. When running the DC locos I use a DC controller. When running DCC locos I replace it with DCC controller. Do not run both DC and DCC at the same time on the same layout
I don't have a DCC layout. I run DCC locomotives on DC.
 
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