Z21 with a Booster

[Despatcher]

I have just finished building a new layout. I have a new Z21. I decided to split the layout which is end to end onto two separate power districts. Each power district is half the layout and each half contains 7 points (controlled with tortoise point motors) and around the same amount of track.

 

I thought that I would split the layout  because I want to use the power bus to control/power the Frog Juicers, Point Motors that I have and any additional accessories in the future as well as cope with around 20 sound decoder locos sitting on the layout with sound on all from one controller. Which is what I believe DCC should be. I also have feeds via dropper wires to every separate piece of track from the track bus.

 

To split the layout I have a Roco 10765 and a Roco 10851 transformer. There are two separate power bus feeds, one for each half. Insulated rail joiners separate the connecting single track line between each half.

 

If I connect the Z21 and the Booster to the layout both halves work fine. Locos run in each half independently without a problem. However as locos cross the gap there is a short circuit as soon as loco pickups are either side of the insulated gap.

 

If I connect both power bus feeds to the Z21 the whole layout works fine and locos a will cross the insulated gap without a problem. I have tried reversing the track feed to the booster.  

 

Any suggestions welcomed. Thanks.

Edited July 9, 2013 by Despatcher

[Despatcher]

Thanks for that. I thought I'd done that by reversing the track in plug on the booster. It has a two pin pug with track negative/track positive attached to each pin. Or is that not what you meant?

[Despatcher]

As far as I can see/understand there is not an output side but I am probably not understanding, sorry. The booster is attached to the track via the track out feed. The booster is then connected to the Z21 through what in essence resembles an Ethernet cable. It plugs into the Z21 via a socket labelled B-Bus, the booster then has two sockets, booster in and booster out. I am using booster in as I am assuming I want the signal from the Z21 to go in to the booster. The only other connection on the booster in the mains transformer. The Z21 only has track out feeds. Am I totally missing what you are suggesting? This is a totally new area to me and I am willing to learn. Thanks for your patience.

[Despatcher]

Many thanks for trying to help. Your time and help are much appreciated. It is a puzzle. As far as I can see, I have followed the instructions in the Z21 manual for boosters. If it did not work when both bus loops are connected to the Z21 I would start looking for crossed dropper wire feeds etc. As it is, I don't know where to start looking. Hopefully someone will have  a thought. 

[loickebros]

Just a silly thought but could the Z21 have reverse loop module built in and you have the 2 halves of your layout wired opposite to each other?

It could be that the higher current with the booster is too much for reverse loop switching that might explain why it works without the booster.

Dave

[Despatcher]

Not a silly thought at all. I'm glad to receive any guidance. Many thanks indeed for replying. But, how would I correct this or investigate? Beginning to wish I had bought a simpler/more mainstream controller to replace my Dynamis. I am beginning to feel an eBay moment coming on!

[loickebros]

Not a silly thought at all. I'm glad to receive any guidance. Many thanks indeed for replying. But, how would I correct this or investigate? Beginning to wish I had bought a simpler/more mainstream controller to replace my Dynamis. I am beginning to feel an eBay moment coming on!

Just reverse the wires to one half of the layout then reconnect the booster and give it a try.

Not really familiar with Z21 but looks like it will be good when you get it working properly.

Dave

[Despatcher]

Thanks for those suggestions. Most helpful I will try both this morning. Not sure if there is a factory reset on either the Z21 or the booster. The Z21 is controlled and accessed through a downloadable "app" on my iPad, it has very few buttons to press, in fact, just one. By itself it is fairly inert apart from on and off. The Booster has fewer buttons and is not accessible/controllable. I will investigate the "app".

 

I have two Boosters as I was going to have three power districts but decided that was overkill for such a small layout. They are both brand new and I have tried swapping those with no difference. I have asked the supplier, Gaugemaster, about the problem and I am waiting for their reply but I only e-mailed yesterday when I posted this.

 

I am off to reverse wires but I will also try the spare track first, thanks for that, sometimes the simple test gets overlooked in the complexity of it all. 

 

As a separate thought, I am wondering also if the Hex Frogjuicers might be playing a part. They are powered from the two separate bus feeds. Perhaps they are causing the polarity difference, which we are all assuming is the problem, when the booster is used. Although my bus feed wires are red and black as are the droppers from the track. I have checked that all "North" feeds are black connected to black and similarly "South" feeds are red to red. The power feeds to the Frogjuicers are all matched similarly, so they should not be a problem?

 

Need to get cracking if I want to see the first ball bowled in the Ashes live. MANY THANKS.

[PaulRhB]

Try asking roco direct through the Z21 website, I had a reply in good English when I asked about higher amp rated boosters for large scale. I've got the Z21 but my OO layout is too small to require a booster and I'll need a more powerful booster for G scale but it will be the only track feed and controlled direct by the Z21 without it being connected to the track itself.

Reversing loops are dealt with by a separate module so there's nothing to set on the Z21 itself, p49 in the handbook.

[Despatcher]

Thanks. I value that and I will try Roco. Z21s are so new that shared information based on usage and reality is hard to come by. I have tried using spare track as suggested. I connected two pieces of flexi track with insulated rail joiners. Connected one end to the Booster and the other to the Z21. In each half the loco would travel forwards or backwards as directed by the Z21 but it would not cross the gap without a short resulting. I have followed the wiring on pp 46 and 47 of the manual. I have the boosters and transformers recommended. If I connect both ends to the Z21 then locos will cross the gap without a problem. I have reversed the wiring in each half and that does not solve the problem. All I have done is replicate and mirror the problem on my layout but in a very simple situation. But at least I now know I can rule the Frogjuicers and my Switch8s out of the problem.

 

I suspect the layout will function without the Boosters but I would like to solve the problem and indeed use them. I suspect recouping anything near the £180 for each of them (I have 2 but I am only using 1) on eBay might be wishful thinking.

[PaulRhB]

If there's a fault and they don't work then you will have a valid reason to return them as not fit for purpose. They are sold as capable so you can get a full refund as they don't work together as advertised. I doubt software updates can solve this if it is a genuine fault as it may be an over sensitive component.

Certainly worth pursuing this as it will help Roco tie it down which will benefit them long term. It's a new system and bugs are inevitable but I like it as the setup is so small and simple and the interface is intuitive. I know it has limitations, such as no consisting at present, but it really has potential being sold as an all in one using technology kids really like too.

Edited July 10, 2013 by PaulRhB

[smokebox]

........ I have reversed the wiring in each half and that does not solve the problem. All I have done is replicate and mirror the problem on my layout but in a very simple situation.

Have you tried reversing the track connections in only one half?

[Despatcher]

Thanks. I like your logical approach. I am off to try this now (both boosters and Z21 as command). Watch this space.

 

I have pinged an email to Roco and I am waiting a reply.

[tetsudofan]

Looking forward to see how this problem gets solved Despatcher as I'll probably be in the same boat as you soon.

 

I'm currently wiring my layout for dcc (having used it as an analogue test track for a couple of years) and am using a Roco MultiMouse but, sitting in the wings, is a Z21 system which I was planning to install once I've decided where to split the layout into power districts.

 

Seeing that we are "local" separated by a short distance of the A259 it is comforting knowledge that there is somebody closeby with a Z21system.

 

Keith

[Despatcher]

Thanks Dutch_Master. Ok, so I have now used both my boosters, one to feed each track/power section and just used the Z21 as the controller. It worked just fine. No problems with the loco going across the gap between the sections. HOWEVER, as I was doing it, I worked out where the next problem would occur and it did. The Z21 has a separate feed to the programming track which, on this layout, is one of the sidings in the shed yard. It is separated from the rest of the layout by insulated joiners and .... yes .... the locos shorted the system when crossing on to the programming track. 

 

So, yes, I could have a totally separate programming track which would work. But that is not what I wanted, so second best. i could go back to analogue and switch the programming track through on/off switches but that is not DCC. What I think, possibly, that I have identified is a compatibility problem between the Z21 and the recommended Boosters which ROCO need to sort. Not sure what to do next now? The Z21 works just fine, the Boosters work just fine fine, unless they are connected as per the Z21 User Manual when they just do not like talking to each other. At least my wiring is OK. Phew! Any suggestions?

[Despatcher]

Keith, glad to know you are there too! I have identified a problem as you have probably read. Not sure of the solution unless it is a patch round the problem. I would prefer a booster that does what Roco claim it does in the User Manual. Not too sure being a Guinea Pig is what I intended when I started this!

[PaulRhB]

Very odd but at least the second booster option works though it is an additional cost. I'd be tempted to still ask Gaugemaster to pursue this with Roco so if a solution can't be found they can ask them to refund and return the lot or possibly refund one booster so you aren't out of pocket.

Fortunately for me as I require the higher amp boosters I'd only be using it to command them anyway so it won't affect my intentions apart from possible product support. The OO layout will be adequately supplied without any boosters as its so small.

[Despatcher]

I have emailed Roco through the contact page on their website. I will add their reply here if I get one. I have also had a long chat with Gaugemaster who suggested that I should contact Roco. On the positive side I can now operate the layout and finish checking everything before adding scenic awe and wonder. On the negative side the ECoS I nearly bought instead would have been cheaper as it turns out! But I really like the Z21 and its range of control from iPads etc and its potential for future updates through Apps. It is very different. Once again I must say how invaluable this website is to the lone modeller working in isolation. DCC is certainly not the simple two wires plug and go it was supposed to be. Thanks to all who contributed and those who are still reading.

[Dagworth]

OK, I think I know where the problem is coming from and it is the delay caused by the processing in the electronics of either the booster(s) or the signal sent from the Z21 to the boosters.

 

The Z21 is putting out its signals correctly, the boosters are putting out there signals slightly out of phase with the Z21. Both boosters connected to the layout means both signals delayed slightly, no short. One booster and the Z21 results in the Z21's section of the layout going from positive to negative ahead of the booster and the short potential across the joint.

 

Look at it like this (I hope this makes sense)

 

(One rail only shown)

Z21 signal

+++---+++---+++---+-+-+++---

Booster signal (delayed)

-+++---+++---+++---+-+-+++--

 

 

Lay both signals on top of each other and you can see that each transition from positive to negative and back will result in a short where the booster and the Z21 are linked via the loco pickups, but as both boosters will have the same delay then the signals come back to being in phase.

 

 

I can't guarantee that this is the fault but it would fit with the symptoms and make sense.

 

AndI

[PaulRhB]

I considered ECoS too but the high cost of the radio handsets and the fact I found them a bit too big swayed me to the Z21. Dagworth's comment makes sense to my limited understanding of signal waves, might be worth sending that info onto them too to give them a possible lead.

Hopefully there might be a fix to that and if you take out the second booster again it should bring the cost back to where it should be. I've got two iPhones, a worn 3 which works fine now most apps are deleted and a 4 plus just bought a Samsung tab2 as throttles. The phones came with the contract and the Tab2 which acts as two throttles cost £140 so effectively cheaper than even the Digitrax DT90.

The potential of the Z21 is good lets just hope these bugs can be fixed soon so it doesn't put people off.

[Despatcher]

I am going to use a switch which will enable the programming track to be used as planned as part of the layout. I also agree that switching it in is a good idea even if it is not really part of the holistic concept of DCC. I once managed to accidentally reprogramme several sound locos by having a wheel over the "gap" when changing CVs on the programming track. We all learn by our mistakes.

 

I just about follow and understand what Andi is saying about Boosters and the Z21 but it is very much at the limit of my aged brain at this time of night! The Boosters are also much older technology than the Z21 as Roco have not produced new ones to complement the Z21. And the Z21 is very much new technology all round. They have just assumed that the Boosters which work with the MultiMaus system will work with the Z21. I wonder if they tested them with a Z21? It will be interesting what Roco have to say if I get a reply. But yes, and many thanks again, I have got a system that now works. Even if slightly differently and more costly than planned.

[Dagworth]

On the programming track siding use a four pole changeover switch (peco sell them amongst others) and arrange a second isolating section between the programming track and the layout so that the second section is completely dead when the switch is set for programming. This has two benefits, nothing can drive onto the programming track while it is in use, and locos that creep forward as the respond to the acknowledgment pulse during programming roll into a dead section rather than livening up the rest of the layout and reprogramming your whole fleet. I've done this on Dagworth where one of the two loco sidings by the station is also a progamming track and it does save the accidents.

 

Andi

[TartanTrax]

Hi Despatcher,

 

Just in case I have missed something, are your Z21 and your booster connected to the SAME transformer?

 

Command stations & boosters require floating voltages to avoid short circuits when a locomotive crosses from one power district to another so each device must have its own transformer or shorts are going to be a problem.

 

Sorry if I'm asking the bleeding obvious but on skimming through this thread I saw nothing saying there were two transformers. Apologies if I missed it.

 

Cheers, Ray

[Despatcher]

Thanks for your comment and interest. Unfortunately nothing as easy though. The Z21 and each Booster have their own dedicated and quite separate recommended Roco transformer. I am still awaiting a reply from Roco Europe.

[Despatcher]

I have received a reply from Roco which I will share with you as follows:

 

17 July 2013 13:20

 

 

"thank you foir your Z21-email-question! With high probability the different
DCC-signals are the reason for the short-circuit for transient-situations:
- Z21 supplies the track with DCC and RailCom-zero-volt-breaks
- booster 10765 isn´t RailCom-abled: For the short gaps there is the full
    voltage, however not in the Z21-region
To avoid this situation you have to switch off "RailCom" at the Z21!

The right polarization between the both layout sections is a necessary
precondition in every case.

With kind regards,

Modelleisenbahn GmbH
Your Roco Service- and Digital-Teams

 

www.roco.cc
----------------------------------------------------
Modelleisenbahn München GmbH
Triebstr. 14
80993 München
Deutschland
AG München . Handelsregister München B159908 . Firmensitz München
Geschäftsführer: Mag. Wolfram Haböck, Mag. Roland Weissenbacher"
 

 

 

As their European Contact page appears in German on my computer and as my e-mail was quite complicated and in English I am amazed at the clarity of the reply. Very good customer services I think. I will try what they are suggesting and report back but, looking at my Z21, RailCom is turned off. Whatever RailCom is.