GeroGero Greensboro, NC
I am new to the z21 system. (Truth be told, I am new to everything about model trains). It seems all my locos are are programmed for the same address: 3. So, I can't run more than one loco at a time. As best I can figure, I need to program each loco with a different address. And to do that I apparently need a programming track. Where do I get this track? Is there a good tutorial somewhere on the web for how to do this?


  • el Gato Gordoel Gato Gordo Colorado Spring

    Greetings, Gero

    You don't need a "programming track" per se.  But this is what you do:

    First, take all your trains off the track but one. This needs to be done with only one train on the track at a time. Second, at the back of your z21 there are 3 plug openings. The one on the right says "Main," the one in the middle says "Prog."  Take your track lead out of the Main and plug into Prog.

    Stage one: on your tablet or smart phone, get into your z21 system, (making certain that your unit is connected to the Z21 router) and go to Programming. Hold it sideways, just so you and I are talking the same language. On the right, "read" the Loco Address. Then tap the address bar to bring up a keypad and use the back button to erase the "3" address. Type in the address you want for that lok and hit "program." Done with the address.

    Stage two: back up to the main menu for the z21 and go into "Railed Vehicle Settings." You will see a plus sign in the upper left corner - tap that. Now look at the center panel and give your lok a name. Below that, enter that lok's new address that you just assigned in the Programming section. you can also enter that lok's max speed.

    (And, if you used your tablet or smart phone to take a photo of all your loks before you started this, you can use a photo for the image of that lok now.)

    You are done with that engine (at least the basics) so remove it from the track and set the next one on. Repeat Stage one and Stage two for each lok.  When you have entered all of your loks in both Programming and in Railed Vehicle Settings, move the track lead wires out of the Prog slot and back to Main.


    If you have any other questions about the z21 or Z21 system, I will be glad to help if I can!  I was in the exact same boat as you just a year ago.  Now I'm the expert?



    el Gato Gordo2015-04-25 21:27:09
  • BR42BR42 Auburn
    Hello Gero:

    What you described occurs on any DCC system if you program on the layout with more than one loco on it.  Gordon's method works for sure, but as the number of engines grows it becomes somewhat tedious to remove all the locos for programming.  Moreover, it is not good for the material to be handled by hand that many times.

    I would therefore recommend to create a programming section.  This can easily been done:  Simply isolate a short section of track with plastic rail joiners (both rails!) from the rest of your layout.  Get a double throw double point (DPDT) switch at a local electronic store (or mail order) and use it to connect the isolated section of track to either the layout (one position) or the programming exit of the Z21 (other position).  An Atlas DPDT relay works too.


    BR422015-04-26 06:58:41
  • el Gato Gordoel Gato Gordo Colorado Spring

    Actually, the double pole double throw switch is unnecessary, Ulrich.  Simply isolate (electrically insulate) a siding or section of track and connect a lead from that section to the Prog outlet on the z21.  During normal operations (i.e., playing with trains) it will receive signals like any other section of track, without any sort of pause as the train transitions from one section to another.

    But Gero is just starting out, and he can get his engines programmed without the programming track right now, and add a programming section when necessary, after a bit of thought about how he wants to do it.

    For a test track that I sometimes use for programming a new lok, I have a short oval of cheap Atlas track pinned to a piece of 2" Styrofoam.  Just long enough of a straight stretch to make railing a lok easy.  I wouldn't run Euro trains on Atlas track as a regular basis, but it seems to be fine for a test track.

    Cheers, all!


  • GeroGero Greensboro, NC

    It worked! You really are the expert! Thank you.
  • GeroGero Greensboro, NC

    I think I understand what you are saying. I will definitely incorporate this into my layout. Thank you!
  • GeroGero Greensboro, NC

    Thanks for this update!
  • el Gato Gordoel Gato Gordo Colorado Spring

    You are most welcome.  For those of us who know or knew nothing about digital at all, the Z21's "instructions" are particularly inadequate.  I had a hard time that I would not wish on anyone else - but thanks to helpful model railroaders like Roger, Ulrich, Ernest and others, I managed to muddle through.

    Now, if only the rest of the world would follow the example of the model railroad world....

    Cheers! and good beer.


  • BR42BR42 Auburn
    Gordon and Gero:

    While trying to help people, I had the "joy" looking at some of the Roco documentation, and found it totally inadequate.  In contrast to this I found that both Lenz and Digitrax were much more helpful not only in their documentation, but also in their Tech Support with Digitrax definitely being the winner.

  • el Gato Gordoel Gato Gordo Colorado Spring

    Hey, Ulrich -

    Ah well, live and learn.  Not being a member of a club (and living 30 miles out of town), I never had a chance to compare systems.  So I cannot advocate the Z21 as a better or worse system than any other - but as you observed, the documentation is terrible.

    Having bought the Z21 and having spent the time to figure it out, I'm pretty satisfied with it. And having spent the money, I do not believe I will invest in any other system.   I'm sure that I have much more to learn about the Z21, and about digital operations in general, of course.

      Puzzling through problems and learning new things staves off senile dementia, nicht wahr?

    Meanwhile, I'll follow your lead and help others where I can.  As always, your assistance is much appreciated!



  • What should I do then if my z21 is the simple version which does not have the "Prog" out?  How can I programme different trains with different addresses?
  • el Gato Gordoel Gato Gordo Colorado Spring

    Hey, Norman

    In the back of my Z21 I have three ports: X-Buss, Prog, and Main.  Are you saying the white z21 system does not have the Prog port in the back?  Do you have more than one of the little green plugs that goes in the Main?

    I suggest taking a spare piece of track and hook up two leads (one to each rail), and connect these to the little green connector that plugs into the Main (removing the lead wires to the layout - I am assuming that you only have one of those little green plugs?).  Then program the addresses to each individual locomotive, one at a time.  This is the time to accomplish any other programming or function assignments, also.  The function assignments come with each lok.  When all the loks are done, wire your layout back to the little green plug and have fun!

    I would be very interested in seeing a photo of the back of the z21, to further my education.  Could you post one?

    Hoping this helps,


  • how can I send photo to you
  • Yes.  My white z21 is the mini version with only one "Track Out" port.
  • Why can't I use the old way to programme the trains as I did with my Lok controller?  Why do I need a so called programmed track?
  • what's the difference between the z21 and the old one?
  • Hi Norman

    Welcome to the Forum!

    The purpose of a 'Program Track' is mostly for convenience. Imagine someone operating a very large layout. There may be several trains with locomotives sitting all over the place, some running, some parked. There may also be several locos parked in a loco shed. I have seen a layout with 15 locomotives sitting on the main track, all at once.

    Now a brand new locomotive is added to the inventory and needs to be programmed. The basic rule is that no other locomotive can be present on the track while a new one needs to programmed. The loco to be programmed must be the only one on the track.

    In the case described above all locos would have to be removed from the track. That is a hassle. The addition of a separate track piece for programming purposes only will alleviate the tedious task of removing all the other locos and then putting them back in their place.

    If your control station does not provide an outlet for a 'Program Track' you can freelance this as Gordon described. You can also put a selector switch into the circuit that allows you to switch the track power between the Main Track and the Program Track.

    The z21 is a less expensive unit than the fullfledged Z21. It does not feature a separate outlet for a Program Track. It is up to you to accomplish this in any way you desire. If you have a smaller layout and maybe only two or three locomotives, you can just simply move the other locos off the track. Just as long as no other loco sits on the track while programming a new engine is in progress.

    That's about all there is to it.

    I might add, that on most control stations that feature a program track outlet, the power provided to the Program Track is a lot less than what is delivered to the main track since only one locomotive comes into the play. I don't know if that applies to the Roco Z21, but it most likely does. In your case it doesn't matter anyway.

    I hope this gives you a little more insight.Choo Choo2015-06-04 10:40:54
  • RailwriterRailwriter Durham, NC
    In case it's not obvious:  The reason you can only have one loco on the track that is being used for programming is that otherwise all the commands you send to the loco being programmed would also go to all the other locos.  And, for example, you could end up with all locos having the same address.


    -- Ernest

  • Dear All,

    Many thanks for your kind reply and detailed explanation.  Now I know what is the real meaning of a programmed track.  Just that I am a starter in model trains and z21, so I don't have a fixed layout and I only played a few trains one at a time.

    I'm using Fleischmann N scale tracks and I'm now planning to set up a very small size layout, say 6" x 3"!!!  How can I find any information or reference on various layout design which I could use on my own layout?

  • el Gato Gordoel Gato Gordo Colorado Spring

    I just now Googled "n scale track plans 3x6" and came up with an amazing number of possibilities.  Are you using a hollow-core door as a base?


  • el Gato Gordoel Gato Gordo Colorado Spring

    Hey, Norman

    I've been thinking about your layout size limitation, and about Choo Choo's remark:

    "If your control station does not provide an outlet for a 'Program Track' you can freelance this as Gordon described. You can also put a selector switch into the circuit that allows you to switch the track power between the Main Track and the Program Track."

    Choo Choo's suggestion is an excellent idea.  Start by electrically isolating a siding.   Then wire two #16 wires out of the little green plug (I use red and black, + and -).  A few inches later, branch off from each of those wires.  One pair feeds your electrically isolated siding directly.  The other pair feeds your main, but goes through a double pole on-off switch.  After the switch you can branch off to feed your track in about 3 places, or more, depending on how many non-programming sidings you have.  When the switch is in the "on" position, all track, including the programming siding, can be used as normal.

    When you want to program something, you drive it onto the programming siding, then turn off the switch to the main line.  Program your lok or other decoder then turn the switch back on.



  • Dear All,
    This is Anthony ( Newbee )
    Q. on Z21. I have Marklin 3 Rail, and the programming out of Z21does not seem to work. (I take note of a double pole switch isolated section idear). However, does anyone have this same problem ?
  • Anthony

    I noticed that, so far, nobody answered your question. Well, here I am, trying to get this thread started.

    Myself, I am a hardcore Maerklin guy. I use the latest Maerklin Central Station in conjunction with two of the latest Maerklin Mobile Stations. I am all set. I virtually have no problems, whatsoever. That's me. Everything works without any glitches.

    I am unfamiliar with the Roco Z21. There are two things about it I do know. It does not support Maerklin mfx decoders. The instruction manual appears to be inadequate, so I gathered.

    I do not know of any Maerklin user employing a Roco Z21. If there is one out there, please, speak up, please.
  • el Gato Gordoel Gato Gordo Colorado Spring

    Hey, Anthony (& Roger)

    My brother is using the Z21 with Marklin trains but is just setting up his system.  Aside from some electrical connectivity (track to track) problems with M track, which I believe we have solved, I hadn't heard of any control problems. 

    Anthony, what have you done so far, to set up your system and get your trains running?  The more detail, the better.  And what decoders are in your engines?  I think Roger could answer questions about the Marklin trains and decoders, while I may be able to handle most Z21 queries.  I've been running Z21 for a couple of years now, albeit with N scale.

    With any luck we should be able to help you get things running.



  • RailwriterRailwriter Durham, NC
    Okay, after reading some Roco documentation, here is my understanding related to this question:


    Both the Z21 and MultiMaus Roco systems can be used to run a 3-rail Marklin layout, if all the locos have either multi-protocol or NMRA/DC decoders.  The Roco systems still send out DC current and NMRA/DC format commands.  If you run equipment only on your layout, it doesn't matter which of the two types of decoders you use.  (You cannot use Motorola protocol only decoders, as far as I know.)


    You would still have the 3-rail advantage of easy return loops without additional electronics.


    If you plan to run your 3-rail locos on other people's 3-rail layouts, you will need multiprotocol decoders so that they also understand Motorola format commands.


    Multi-protocol decoders are a little more expensive, but then will work both of the major command formats.  Programming, such as address, speed, etc., should work in either format -- with some limitations.  See the decoder instructions.


    (Inversely, you could also run a two-rail layout with a Marklin command station, if all your locos have either Motorola format or multi-protol decoders.  You could not run locos that had only NMRA/DC format decoders.)


    I hope that helps.  Anyone disagree?


    -- Ernest

  • BR42BR42 Auburn

    The rail system has no influence on the type of decoder you use, it is simply a myth spread by some companies.  Therefore, you can use a Z21 for 3-rail locomotives, provided as was said before that they are equipped with a decoder which understands the NMRA/DCC signals, i.e. a NMRA/DCC-decoder or a multi-protocol decoder.  Here is now the problem:  Most decoders which installed in locos for the 3-rail system By Marklin do not have this capability.  Therefore, you have to buy either a mufti-protocol command station that "speaks" NMRA-DCC, MfX and Marklin-Motorola, or swap all the decoders which do not speak NMRA-DCC.

    It has been a long tradition of European manufacturers to make their trains incompatible with those of others.  While the struggles of the European version of the NMRA finally yielded compatibility with respect to wheels and coupler boxes, the introduction of command control started things again:

    Marklin -  Motorola first, then MfX

    Fleischmann - FMZ

    Trix - Selectrix

    Only Roco was sane, they used standardized NMRA-DCC from the beginning.   Fleischmann and Trix gave up on their house-brand and switched over to NMRA-DCC.  

  • Dear All,
    Starting at the beginning-- 3rail-Mainly Marklin-ICE-I think a lot have Motorola ,then Fleichmann DCC type Loco's, Roco, Brawa and even the latest camera Roco. Quite a mix.
    Now I started with, and still have Viesmann 5003 commander thinking the way to go forward only to find out that the computer out of the Commander is NOT DATA RICH !!!!!!!. I wanted to go to computer control.
    to enable computer multirouting as I have a bit of a rubics cube of a layout. So now I have the commander as a programming caperbility trying to introduce the Z21 in to be the new controler to speak AC voltage to the track and be a way of running camera trains.
    The final thing will be to hook up via LAN to the computer with 'Trian Controller' Gold so as to manage all of the difficult routing and speed scheduling
    With my hope to join Z21-Train Controller Gold, it seems that my hope of plain sailing is going to be a big stretch.
    I can live without some of the fancy MfX functions if necessary.
    With the info from your replys I may be in a bit of a fix. Please comment.
  • Dear all,

    I found that the z21 app is really hard to use.  There are a lot of settings that I really don't know how to set, like the z21 setting and the programming setting.

    Besides, what are the difference of "Program on Main", "Program Track" and "Program Address"?  When I program the second loco, which option should I use and how to use?

  • Dear All,
    Any quetions I answer will have to be a little remote. Let me explain, I am about 4000 miles away from my layout. I am using a Samsung Tab 3 for my controling peace of glass.
    Now I have come across a worthwhile bit of help in the form of ' www.z21.co.uk' This is done by a guy in a shop in UK called 'Gaugemaster.co.uk'where turnouts are called switches.
    He has done the first bit in very clear easy steps. When you have finnished that, then go to Loco Functions. Anyway see what you all think.

  • Hi All.
    I am getting confused now. I meant 'turnouts are called points

  • BR42BR42 Auburn

    I think you are trying to do a technological "overkill".  If you want to have computer control at the level you are describing, then it might be the best to have the computer itself generate the multi-protocol DCC-signal, and just run it through a booster.  If you are new to DCC, I would start with the multi-protocol command station, like the one from Viessmann, and see if I can get things to work smoothly.  If everything works, you can connect the command station to the computer and have it provide routes and other fancy things that the command station cannot do. 

    If I understand things correctly, you want to use the Viessmann because it speaks Motorola, and add the Z21 because it has more fancy  abilities, but keep the Viessmann at the same time.  Adding a Z21 command station to get these additional features, but loosing the multi-protocol ability at the same time would require running two command station at the same time, not a good idea.

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