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The Science of DCC

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  • Member since
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  • From: Ridgeville,South Carolina
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The Science of DCC
Posted by willy6 on Wednesday, December 27, 2017 10:15 AM

I just got reading on Wikipedia of how DCC works. It's kind of a cross bred AC / DC signal of what I read. But I have a question that wasn't answered on the Wikipedia. It stated each decoder has a "unique" address, does that mean each decoder made has a unique address or does it mean the operator makes it unique by putting in locomotive number? I guess what i'm getting at is if I program 2 loco's #1234, would both of them run when #1234 is selected?

Being old is when you didn't loose it, it's that you just can't remember where you put it.
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  • From: St. Paul
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Posted by garya on Wednesday, December 27, 2017 10:24 AM

willy6

I just got reading on Wikipedia of how DCC works. It's kind of a cross bred AC / DC signal of what I read. But I have a question that wasn't answered on the Wikipedia. It stated each decoder has a "unique" address, does that mean each decoder made has a unique address or does it mean the operator makes it unique by putting in locomotive number? I guess what i'm getting at is if I program 2 loco's #1234, would both of them run when #1234 is selected?

 

Short answer: yes, they will both run.  The unique address is prgrammed by the operator.  I have friend who runs two locos of the same type and manufacture together all the time, so he just programmed them with the same address.

Gary

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  • From: Western, MA
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Posted by richg1998 on Wednesday, December 27, 2017 10:25 AM

willy6

I just got reading on Wikipedia of how DCC works. It's kind of a cross bred AC / DC signal of what I read. But I have a question that wasn't answered on the Wikipedia. It stated each decoder has a "unique" address, does that mean each decoder made has a unique address or does it mean the operator makes it unique by putting in locomotive number? I guess what i'm getting at is if I program 2 loco's #1234, would both of them run when #1234 is selected?

 

The operator enters the address for each decoder.

Look at the DCC manuals online.

Some do program two locos with the same address when running together. I don’t.

I use the NCE Power Cab.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

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Posted by tstage on Wednesday, December 27, 2017 11:06 AM

Yes, the operator programs the short and/or long address of each locomotive using their DCC system.  The default for each decoder is "3" but you can choose addresses from 0001 to 9999.  Generally users choose the locomotive's road number for obvious reasons.

Should you have two locomotives with the exact same road number, you would need to find an alternative number for one of the locomotives.  Programming them to the exact same address will cause both to respond when selected on your DCC throttle.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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  • From: Reading, PA
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Posted by rrinker on Wednesday, December 27, 2017 9:05 PM

 Each decoder must be programmed with an address. Per the NMRa standards, a brnad new int he package decoder will normally be programmed as address 3. That way, you can easily test a new decoder without doing any programming. But of course it would not be practical to have a whole fleet of locos all with decoders programmed to address 3 - they would all move at the same time and you would be no better ff than with DC - you'd have to create blocks or somehow regulate which locos get power at a given time, which completely defeats the point of DCC. So instead, you program each decoder with a unique address, and then ONLY the loco you address on the throttle moves.

 With most DCC systems, if you select a loco and start it moving, then select a different loco, the first one continues to move at the same speed and direction it last was moving. So you can start one train circling the main line while you select a different one and switch in the yard.

            --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by PC101 on Monday, January 1, 2018 5:17 PM

As a side note, if you have two locos. adderssed with the same number and both are closely forward facing each other and you thow the direction switch to FORWARD they will run in to each other. Now if both are still forward facing each other and you throw the direction switch to REVERSE, they will move away from each other. 

The decoder in each loco. with the same adderss can be set for the long hood or short hood to be the forward direction. That way you can run Elephant style (lead loco. forward, trailing loco. forward) or (lead loco. forward, trailing loco. backwards) style. 

Woops I see what I posted above was questioned and anserwed in the "Two trains at once" post by Semi4. Sorry.

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