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*What is the maximum size of layout you can run with just one Digitrax command station?*

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*What is the maximum size of layout you can run with just one Digitrax command station?*
Posted by Union Pacific Cascade Division Model RR on Sunday, March 16, 2008 12:47 PM
I am getting ready to build a brand new shelf layout in a room about the size of a guest bedroom. It is going to have a single mailine around the room with one passing siding and a few industry spurs. I will be running three engines at a time. Will a top of the line Digitrax Command station be enough to run the whole layout with out adding more boosters?
Union Pacific Building America
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Posted by jamnest on Sunday, March 16, 2008 1:25 PM

You said "top of the line Digitrax Command Station"; which I assume means a Digitrax Chief (DCS-100) which is rated a 5 amps. The Digitrax Chief set does not come with a power supply, so you will need to purchase a 5 amp power supply.  A consertive estimate would be to allow at least one amp per sound locomotive, so three sound locomotives would be well within the limits of this sustem.  The Digitrax DB-150 which is the command station for the Empire Builder is also rated at 5 amps, but you can not read back CVs when you are programing.

If you are only going to run three locomotives, a Digitrax Zepher may be all that you need.  The Zepher set includes a power supply, it reads back CVs, can be interfaced with a computer (MS-100 or USB Locobuffer required for this), can be upgraded to radio control (UP-91 radio receiver needed for this) and can do "Blast Mode Programing" which is needed for sound decoders.

Jim, Modeling the Kansas City Southern Lines in HO scale.

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Posted by gandydancer19 on Sunday, March 16, 2008 1:31 PM

If three engines are all you are going to be running at one time, you may be able to get away with getting a lesser system, unless you want something that can be added to for signaling and turnout control by stationary decoders. A general rule of thumb may be to say that each sound loco will use one amp when running and perhaps half of that when just sitting still. So figure out how many locos you will have total on the layout at any given time and how many will be running at the same time. Add the figures together and that should give you the total amps of the system that you should possibly look into getting. I have a single car garage size layout under construction, and I have six sound locos that I will be using and they will all be powered all the time. I will be running two, maybe three at a time. I have a 5 amp NCE power pro system and fully expect that this system will handle my needs. If you are going to have a lot of locos, but only run a few at a time, you could add an off-on switch to the tracks that you plan to store the locos on that you are not running. This will reduce the system current (amp) requirements. This used to be something that you HAD to do on a DC layout, but since the introduction of DCC, I haven't seen many folks go for this option. They just buy more boosters. The way you choose to go depends on your funds you have to work with.

Elmer.

Elmer.

The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.

(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.

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Posted by CSX Robert on Sunday, March 16, 2008 2:29 PM
One thing nobody has pointed out to you is that there is no limit on the size of the layout you can run with a single command station, the limit is on how much current the engines will draw. You could run a basement size layout off of a Zephyr as long as you did not exceed 2.5 amps.
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Posted by jfugate on Sunday, March 16, 2008 3:50 PM

Layout size doesn't matter one iota with a DCC system. If you can run wires to the track, then any DCC system of any size will work.

The limitation is the number of locos you will be running at the SAME TIME, since the current limit of the system determines how many locos you can run at once.

For simple math, assume each loco draws as follows:

Non-sound loco: 0.25 amps

Sound loco: 0.50 amps

So take an NCE PowerCab, with a 1.7 amp capacity. This system will run up to 6 regular locos at the same time, or about 3 sound locos at the same time.

If you run multi-unit lashups (as would be typical with modern diesels), then each loco counts against the capacity.

So THATs your limit. It's also considered good practice to not try to power any given section of track in HO with more than about 5 amps. So if you have a larger layout, you will want to have several 5 amp sections, each one powered by a 5 amp booster. 

Joe Fugate Modeling the 1980s SP Siskiyou Line in southern Oregon

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Posted by Union Pacific Cascade Division Model RR on Sunday, March 16, 2008 9:02 PM
 jfugate wrote:

Layout size doesn't matter one iota with a DCC system. If you can run wires to the track, then any DCC system of any size will work.

The limitation is the number of locos you will be running at the SAME TIME, since the current limit of the system determines how many locos you can run at once.

For simple math, assume each loco draws as follows:

Non-sound loco: 0.25 amps

Sound loco: 0.50 amps

So take an NCE PowerCab, with a 1.7 amp capacity. This system will run up to 6 regular locos at the same time, or about 3 sound locos at the same time.

If you run multi-unit lashups (as would be typical with modern diesels), then each loco counts against the capacity.

So THATs your limit. It's also considered good practice to not try to power any given section of track in HO with more than about 5 amps. So if you have a larger layout, you will want to have several 5 amp sections, each one powered by a 5 amp booster. 

Thanks for the input on this issue. It looks like I won't have a problem with my current system. To change the subject, I have been doing some serious searching for ideas on track ballast. I saw some of the photos of your layout and I am really impressed with the color. Could you give me the info on how I could duplicate this? Thanks!
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Posted by jfugate on Monday, March 17, 2008 12:50 PM

Ballast color is rather off-topic here, but you can check out my scenery forum clinic here for more details.

Back on topic, sounds like you get the picture with layout size and a DCC system. It's the number of things (locos) you put on the track that draw current that is the real limit ... and the current capacity of your system will limit how many locos you can run at once.

Notice it's the locos that are *running*. You can have 1,000 locos on the track, but if they are just sitting they won't be drawing power unless you have sound locos and you leave the sound decoders on all the time (not a good idea, since that counts against your system's capacity -- you are well advised to find out how to set the sound decoder to shut off when the loco's not in use). 

Joe Fugate Modeling the 1980s SP Siskiyou Line in southern Oregon

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Posted by MisterBeasley on Tuesday, March 18, 2008 9:25 AM

It doesn't sound like it's going to be an issue for you, but you also need to consider other things that draw power from your tracks.  In particular, illuminated passenger cars or cabeese will each need to be added to your current needs.  (Some cars use batteries to run internal lighting.  Those don't count here.)

A few modellers ask about powering structure lights from their track bus.  Well, yes, you can do that, but once again, it counts against the limited capacity of your DCC system.  In general, you want a completely separate power source for structures.  (Separate, as in "plugs into a different socket in the wall.)

It takes an iron man to play with a toy iron horse. 

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Posted by SilverSpike on Wednesday, March 19, 2008 9:51 AM
 jfugate wrote:

Notice it's the locos that are *running*. You can have 1,000 locos on the track, but if they are just sitting they won't be drawing power unless you have sound locos and you leave the sound decoders on all the time (not a good idea, since that counts against your system's capacity -- you are well advised to find out how to set the sound decoder to shut off when the loco's not in use). 

What I have done to resolve the locos with sound decoders on the track issue is to install separate SPST toggle switches on the 6 track sections within my roundhouse and will install them on other track segments where I can park the sound equiped locos and just switch off the power to the track segments.

Ryan Boudreaux
The Piedmont Division
Modeling The Southern Railway, Norfolk & Western & Norfolk Southern in HO during the merger era
Cajun Chef Ryan

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Posted by rolleiman on Wednesday, March 19, 2008 3:34 PM
 jamnest wrote:

 

If you are only going to run three locomotives, a Digitrax Zepher may be all that you need.  The Zepher set includes a power supply, it reads back CVs, can be interfaced with a computer (MS-100 or USB Locobuffer required for this), can be upgraded to radio control (UP-91 radio receiver needed for this) and can do "Blast Mode Programing" which is needed for sound decoders.

This is true of all the current digitrax systems. The interface is based on the loconet and is not system specific. I don't know about the Zepher but an additonal difference between the chief (which is available in 8 amp btw) and the Empire builder is the ability to have a programming track seperate from the layout. The EB broadcasts all programming commands to all decoders that are on the active tracks. I will say however that the ability to have a programming track seperate from the layout was worth the upgrade to me from the DB150 to the DCS100.

You (the OP) might do well to seek out the DCC megathread and read through it. Aside from all the X vs Y vs Z arguments, it's a very informative read.  

BTW, I've never had a problem programming Sound decoders (BLI, SOUNTRAXX, etc) with the Chief.  

Modeling the Wabash from Detroit to Montpelier Jeff
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Posted by jfugate on Wednesday, March 19, 2008 4:33 PM

All NCE systems from the PowerCab to the ProCab take the main track power offline when in Programming mode, which is one of their more significant disadvantages. It all depends on how you do your loco programming. Only once in a while is a programming track even needed these days ... you can do almost everything you ever need to do using ops mode programming -- that is programming on the main (POM). Once you get used to POM, you will find you seldom use the programming track (mainly for debugging issues, since the only place you can read back CVs is on programming track).

If you came upon your ProCab in an evolutionary manner via the PowerCab, then you still have the PowerCab parts that can be used to power a separate programming track, allowing you to program locos (mainly, to read back CV values) without taking the ProCab main track power offline.

There are other options too, like using DecoderPro and a sprog to power a stand-alone programming track.

But it is very nice that the Zephyr keeps the track power on while using the programming track. 

Joe Fugate Modeling the 1980s SP Siskiyou Line in southern Oregon

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Posted by simon1966 on Wednesday, March 19, 2008 4:43 PM
 jfugate wrote:

But it is very nice that the Zephyr keeps the track power on while using the programming track. 

You are not kidding Joe, I use this feature all the time. I have built my programming track into my loco maintenance area specifically at the sanding and water tower area and protect it with the dead track sections that you described many moons ago.  I just run my loco into the spur, throw the switch on the fascia and program away to my hearts content either with Decoder Pro, or simple things via a throttle.  Mean while the boys can keep running trains on the rest of the layout.  When done, jump out of program mode, throw the facia switch and head off onto the layout.

Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum

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Posted by jfugate on Wednesday, March 19, 2008 5:06 PM

Simon:

I'm curious, what kinds of things are you programming? The reason why I ask is if you're moving the loco to the programming track, then changing some CV setting -- you don't need to do that on the programming track at all, most likely. Programming on the main (POM) should cover it.

Joe Fugate Modeling the 1980s SP Siskiyou Line in southern Oregon

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Posted by simon1966 on Wednesday, March 19, 2008 7:16 PM

Joe, recently I have been installing new decoders in several locos and have added some new decoder equipped locos to the roster.  First trip to the program track is to validate my install in a controlled environment, set the address and not much else.  Once I have run the loco for a while I will use Decoder Pro to then set up my lighting effects, sound levels, speed curves etc.  Since I do like to then like to save my final settings in Decoder Pro and my PC is sitting right next to the program track in the yard, it simply works best for me to do it this way.

Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum

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Posted by jfugate on Thursday, March 20, 2008 12:14 PM

Ah yes, Simon, that makes sense. Yes, a stationary programming track works very well in concert with DecoderPro (cuz it's right next to the PC), so I understand!

Digitrax keeping the main track powered while in programming mode does give you more options, no doubt about that. 

Joe Fugate Modeling the 1980s SP Siskiyou Line in southern Oregon

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