Newbie questions : LUSENET : Wiring for DCC : One Thread


I've very new to model railroading...but a veteren in computer networking. I'm sold on DCC for my layout (which is still in the design phase). And, am leaning heavily towards Digitrix.

But, I've got a couple of newbie questions:

1. Can two locos be on the same track but moving in opposite directions? From what I've read I'd like to avoid the hassle of wiring reversing loops.

2. I expect to have between 40 and 50 feet of track. Will I need more than one booster?

3. Am I right in assuming that switches can be controled from the same contorl unit a loco is controled from?

4. If I buy a loco with a Lenz decoder will it work ok on a Digitrix system?

Thanks in advance for the advice


-- Eric Miner (, October 19, 1998



I hope you are sold on Digitrax..

Yes there is no problem with loco control, each loco is controlled by it's own address. This means you have total independent control. You can run in any direction. This means opposite directions. Cornfields are very possible.

As far as actual reverse loops or sections. This is where the polarity of the rails reverse. Here the results are the same. That is the polarity of one side or the other of the gaps must change to match. All the methods with DC work with DCC. But DCC also tries to make this a little easier and even automatic if you like. Boosters such as Digitrax are all autoreversing, or you can use one of several modules on the market, that will reverse the polarity for you also. Units such as the Lenz, Loy's Toys, or the MRC.

As far as how many boostes you will need. This will depend on what scale you model in and how many locos you plan to run at a given time. Again the Digitrax system, has your first booster built into the command station. This will supply either 5 amps or 8 amps of current. Seeing as a typical HO loco draws less the 1 amp, you can get an idea of what kind of power you will need.

As far as turnout control, yes by the use of additional stationary decoders such as the Digitrax DS54, CVP AD4, etc. You can control your turnouts from Local panel, your throttle/s and/or computer. With the DS54 you can also have turnout positioning indications.

As far a Lenz decoders, and for that matter any other make of DCC decoder. There is no problem. This is the main advantage of DCC. Thanks to the NMRA Standards and Recommened Practices. These help insure that decoders from one DCC manufacturer work with a DCC system from another manufacturer.



Remember Always Have Fun and Enjoy!, Don Crano Akron, Oh NMRA #096211 Visit Model Railroading with DCC at:

-- Don Crano (, October 24, 1998.


The choice of DCC will defintely allow for operations by control of individual motive power separately. Some systems have multiple engines control directly at each handheld (called a CAB - much like a throttle). Other sstems have one CAB control for each engine running at the same time (the CABS caan be assigned to ANY engine available - one at a time - except inthe case of multi-unit consists - see below). You can have several switchers in a yard - each moving back in forth in differing directions - and YES you can have them run into each other head on.

Get a copy of the "DCC Handbook". Many dealers now have them and they can be purchased from mailorder as well. It's a basic bible that explains a lot and includes some very good rational on the why's of many aspects of things in the DCC world.

Before you pick a system - any system - get around to some actual installations - operating sessions - clubs - other individuals, etc. Be sure a see how the various CABS and the user interfaces operate. Look at how the set up (programming the engine decoders can and is done for each system). Even some of the systems have multiple choices of the handhelds and their functions. Get a feel for what is comfortable for you. I use a different system than Digitrax and I'm most pleased with my choice for the kind of operations I do. Most all the systems will be introducing radio or IR cableless controls. Some have them now - but the market demands are forcing all to have them soon. Be sure and watch out for what controls actually are in the un- teathered versions. Some still require the acquisition of the CAB to be done in a connected fashion - then you can control the engine or consist in on the road operation.

By the way - consist - several (some systems infinite) engines can be hooked up together and assigned as a single engine - allowing for multi-headed operations. With quality decoders - the individual engines running charateristics can be 'tuned' to match one another for smooth joined operations. ANY conforming decoder can be at least controlled by ANY conforming command station. Some systems don't have all the advanced newer stuff - and can't necessarily make all the programming changes of some features of other components - and some have it - but the painful means of getting the programming done will make you want to eventually opt for a more advanced system. Pick a system that has a good balance of capability and ease of use for your style of operation. SOON - but not immediately today - you will want to insist on ALL components being a true 'conforming' system. (Note that conforming is not the same as 'compatible'). Conforming is a much stricter and third party checkout that is awarded by the NMRA for meeting the standards and (IMPLEMENTED) recommeded practices. I emphasize the 'implemented' because only the features claimed to be present are tested - and if OK - then a conformance is awarded. This means you'll need to become savey about what YOU want and need for YOUR system.

I know this is a lot to digest when you are getting started - but get a copy of that handbook, check out actual systems in use, and welcome to the world of operating model railroads!

-- Ed McCamey (, October 24, 1998.


I can not agree on the Conformance issues atleast not yet. There is a long way to go before that should even be a deciding issue on the purchase of a DCC system or especially a decoder.

All the major systems have conformance on their command stations. And some such as Digitrax have a couple different command stations with warrants.

But since 1996 todate, there is no full feature decoder with a warrant. So if one wants to use conformance as a issue they will be limited to 28 speed step decoders.

There are also to many problems with in the conformance issues at this time also, it is being worked on and changes made, but there is still aways to go.

There are issues of what actuall falls under the ST and RPs, there are RPs that apply and those that do not. No one even knows for sure what those are. There are waivers given, and we do not know what is what here. So there is no way to tell when a product has a warrant, what all is covered under that warrant.

Using conformance as a selecting guide is ok. But some of the best equipment on the market does not have a warrant. One would be limited in decoder selection to less then full feature decoders with on 28 speed steps.

Compatablity is the name of the game. Conformance is just a tool that is suposed to insure compatablity, but the manufacturers have been doing a good job of this by them selves. They have to or we the consumer do not buy it.

May be some day conformance will be a good point for purchasing issues. But as long as there is only less then the top of the line systems, only less then full feature decoders. Warrants given to locos that do not even come close to following the DCC ST&RP. Some of which were never even tested with DCC period. Infact as per RP, there is not one DCC loco that has pin 1 of the NMRA DCC socket properly marked that I know of. And the only one that I know of that is even marked, not properly but marked, has 6 of the 8 pins miswired. There is still a loco with a warrant that if pin 3 is used, the decoder function blows. No it is not a issue of concern for purchasing.


Remember Always Have Fun and Enjoy!, Don Crano Akron, Oh NMRA #096211 Visit Model Railroading with DCC at:

-- Don Crano (, October 25, 1998.


I understand the views on conformance. I started the view with the preface of SOON as an important intro to the issue. Conformance only means cmpatibility with the features choosen to implemented. It does not mean requiring all the RPs be fully implemented - only that what is implemented must be correct. There is not any misunderstandings on the difference between the Standard and the RPs. A very simple 14 step speed and direction decoder that complies with the standards alone can get a comforming Warrant. I'm well aware of the warrant for the 2-8-0 being withdrawn when the pins were mirror reversed on the first production run (which is now fixed in the latest run). The real power of the conformance program is the maunfactures agreement to fix subsequent discovered errors. The present RPs have several areas of 'still under review' and there are manufactures that are supplying their versions of what they think that subject area should be. Reference the acknowledgement mode of runing - not yet defined by the RPs, under review and testing - but being supplied by one manufacturer. When that decoder is also on the mains with certain other decoders there is a conflict. Conformance means allowing for the conflicts to be worked out in all the preliminary testing and be able to be compatible when finally issued - and with a commitment for fixes. I'm delighted that Digitrax has submitted and received warrant for their new commandstation/booster unit. I'm aware that you also particpate regularly on the DCC-SIG and keep in touch with the unfolding developments. I have my own choice of system, the components are conformance warranted, but I choose not to directly post my influnece on that system specificly - especially to the new comers. Very clearly, there is a diference in the systems - mostly and dramaticly in the user interface. (The technical differences in the command bus, the booster bus, and the developing feedback bus are also a subject of lively debate). What a new comer really needs is advice of what can be done, how to do it, and some sound direction to find the right answer for that individual. I belive that Stan, Rutger, and Ed's advice in the Handbook provides very concise and sage information. I mix and match several components myself. I have some homebrew attachments, and I use several different decoders. I follow your tips and home pages regularly. I know that you have a better than fair technical background for DCC, and can be counted ponto explain and help diagnose problem issues. To postpone conformance as an important issue suprises me. It certainly is soon to be preaching mandatory conformance - but I suggest that conformance is an important direction for consideration. -ed mccamey-

-- Ed McCamey (, October 26, 1998.

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