jamesed

So what value have you got for cv36? This must be the key because if F2 is operating it then that's the value you want to know.

I think that's the point John is making. With a default value of 4 cv35 is mapped to F1. However, you have already stated : so that means logically you must have a value of 8 on cv35, not 4. If your cv value is definitely 4 then that implies that the green and purple wires have been reversed somehow. If F2 is switching it correctly then try mapping cv36 to F5 (cv36 = value 64) and see if that works.

Thank you John for pointing me in the right direction. It's actually cv124 to value 128 which was needed (bit7 on) but once I knew what I was looking for it didn't take long to find that. The previous default setting for cv124 was actually 3. The light bar now switches as it should. It's the first time I've used the Dapol light bars and I'm quite impressed with them. Do you happen to know if they'll work in the same way with the cheap Lais N18 decoder (I'd only use these as an accessory decoder in the non powered car). If so I might fit them to my Class 43 HST set but will need a lot of cheap decoders if I'm going to fit them to all the Mk3 coaches.

Thanks John. I'll give that a try and report back. James

Hopefully someone can suggest what might be my problem here. I've installed a Dapol light bar into my new N gauge Class 153. The decoder I'm using is a Zimo MX618N18. The Dapol instructions with the loco state that the light bar is wired to Aux4. My function mapping is correct (I've tried it to F4 and also to F1) but the light bar just remains on the whole time. For some reason I can't switch it off. I've tried both the usual offset mapping and the Zimo alternative mapping. I've also tried resetting (cv8=8) a couple of times but the light bar just stays on all the time. It only goes out if I remove the decoder from its socket. Any ideas or suggestions?

Iain, am I missing something here? Surely if the z21 doesn't have a programming track set of outputs, and the only set of bus outputs are for a main track, then the program track menu in the app doesn"t do anything. Therefore the only option you have in manual changes is to use the POM option. My own system is a Z21 (black) so I don't have that issue but surely that must be the problem for the OP who only has the white z21..

The z21 (white) doesn't have a separate programming track output. The programming track option in the app isn't the correct one to use. That's for using with the Z21 (black) which does have the separate output.. Try using Programming On Main menu in the app and it should work.

Errr isn't the whole point of using the Z21 layout plan that this becomes your touch screen mimic. Why would you need a separate mimic panel when the touch screen version is superior in every way?

As a general rule, the lower the impedance of the bus wire the better the quality of the dcc signal will be maintained. The nature of a ring circuit is that the impedance is reduced by up to half. Most quality dcc controllers (but possibly not the one which recommends against a ring circuit) will have suppression circuitry built in to its output. Therefore, if both ends are terminated there they are both protected and there's no need to install snubbers as long as you have kept to a ring and don't have any spurs. There is some nonsense written around the web that says if the dcc signal is arriving from different directions that it can be out of sync and cause phase cancellation corruption but this would only be an issue where the bus wire is something like 3km long. Consequently that argument can be dismissed for virtually all model layouts. There is also one particular uk manufacturer which likes to perpetuate this myth that ring circuits are bad and that it's much better to have a radial with snubbers fitted at each end point. However, despite them being challenged on this point a number of times I've never seen them come up with satisfactory scientific justification for that claim. If one was being cynical then one might wonder whether the fact that they make and sell their own snubbers might be influencing their point of view.

That's a myth which isn't supported by any half reasonable scientific justification. It's perfectly ok to wire your bus as a ring and, in fact, there is some scientific justification as to that being a good thing to do.

Put both cars on the program track and set the main address and make any other simple adjustments you want to. Read cv29 and whatever number is returned, add 1 and reprogram (that will reverse the direction of travel for both units) Now take the unpowered car off the track and reprogram cv29 in the powered car to the original value (-1). Put both cars on the main track and you should now find that the directional lights work as they should.

LED lights typically last for around 50,000 hours give or take a bit. If your light is used for an average of 8 hours per day that would last around 17 years. In reality it's more likely that the electronic components in the fitting will fail first but 10 years is a realistic expectation. Just make sure that you don't try and run them from a dimmer switch unless a) the fitting specifically says it can be used with a dimmer switch and if so, b) the dimmer switch used is of a type specifically suitable for led lighting.

Glad you have got it all working as it should. It's that bit where you go from program track to manual and it reverts back to a POM page that's confusing. You're not a moron Eddie. If you were you wouldn't even have got as far as trying manual programming of cv values. It's all a learning curve for us all. Enjoy your Z21, it's a great bit of kit.

I'm with John on this, what you have described so far doesn't add up. Firstly, are you sure you are using a separate programming track which is completely isolated from the rest of the layout? If so, why have you put several locos on it at once - that won't work unless you are wanting to reset them all and then program them all the same. Try doing one loco at a time on the programming track. First, once you have one loco on the track, go to cv programming and touch the loco (program) button top right. The, try to read the loco properties. That may or may not work depending upon your decoders. I mainly use Zimo and they always read. Assuming that this doesn't work, click on the manual button at the top of the screen. Now this is the point where you may be going wrong. Once you click on manual it defaults back to a POM screen. You now have to select program track in the left hand menu. Once you are in the correct screen the top variable which it will ask you to enter is a cv value (NOT an address value). So, put in cv#1 and then click on the 'read' button. This should return the value set on your loco for cv#1 which is your address. If you want to change the address then manually change the value and click on 'write'. It's the same for any other cv values you want to read or change for that loco. Enter the cv number, read it, write the new value. The method you described of entering an address number and reading is the way you use the POM function. That's fine too if you want to program on the main track but you will need to check the cv#29 settings as Nigel has explained and just beware that this may not work with all decoders. There's also an argument that if you don't need to use railcom then it's better to have it switched off anyway. One of the big benefits of the Z21 over the z21 is that it has the separate program track output so you may aswell use it. You're less likely to get in a mess if you stick with one loco at a time on the program track.

The Gents toilet was/is the one which is accessed from along the subway linking the station concourse to the Regent Street / Sherwood Street entrance/exit. I used to work up there in the 1980s and walked past it daily. The toilets themselves were to be avoided at all costs as they were the place where men looking to pick up another like minded man for dubious reasons hung out (poor choice of words but quite accurate).

Your 90x19mm 'pine timber' is actually PSE and starts off as 100x25mm (4"x1" in old money). It's then planed down to 90x19mm with square edges. I used 75x25mm (3"x1") for my frame which is planed down to 70x19mm. That's still pretty sturdy and would do just as well for you. It may save you a bit of money too given how the cost of timber has risen.

Before you finalise where to put legs and cross braces, take a look at your track plan and work out where points will be. You'll need the underside of the board clear of legs and cross battens where you want to install your point motors. With a 4x1 frame (you could just as effectively use 3x1 PSE) you'll find it will be sturdy wherever you place your legs even if they aren't spaced evenly. For my money, 9mm ply every time for the top sirface. Paint the top boards both sides before you fix them in place.

The system requirements don't actually state the RAM requirement. That's helpful information if the german language version of the same faq page states 2Gb. That would certainly be more realistic in my view. I did email Roco to ask them to clarify this last year but never received a response. My best guess is that 2Gb is absolutely fine but, in general, the more RAM you have, the better. If using a 2Gb device just check your app housekeeping. Most Android devices come with lots of pre-installed apps that run in the background that you may not need. Social networking apps, store apps, newspaper apps etc. usually are running continuously and will be using RAM. 'Force stop' or delete any apps you don't need to run which will leave more memory available for what you want to run. Keith, Random Access Memory or RAM is different from storage memory. It's what's used for processing the operating system or apps when they run. It's always listed separately in the specification of the device although, from a sales point of view, storage capacity is usually given more prominence so you may have to look for it in the full spec list. If you buy a new Windows laptop, for example, most will come with 4Gb or 8Gb of RAM. These are usually plug in chip sets that can easily be upgraded if required and some manufacturers offer this as an upgrade service or it's easy enough to do yourself. Having more RAM can significantly speed up your laptop if you are asking it to do a lot of things at once. The same principle applies to mobile devices except that you usually can't upgrade the factory fitted RAM yourself.

https://www.z21.eu/en/faqs-support/questions-answers# At question 1.3: The app can be used in iOS 11 and above, and Android 5 and above (with min. 5 GB RAM).

A couple of things here worth noting. In the Roco FAQs for the Z21 it states that a tablet will need to have a minimum of 5Gb RAM. That does seem very high and would restrict use to only premium devices. I did email Roco to ask about that but never received a reply. I guess it's going to depend on how much you are going to be running on your Z21 app at once and also how many other apps you have running in the background at the same time. Most cheaper tablets and phones only have 2Gb RAM but many people report using these successfully. The Samsung A7 has 3Gb. I run 2 x Lenovo M10 tablets each with 4Gb RAM (which you can pick up for £149 each) and they are dedicated for use on my model railway so don't have other apps (except for the ones you need) running in the background. They work very well and as they both run the same layout (transfered by device to device export option in Z21 app) then I always have a backup. (I normally use one for controlling trains and the other for layout devices such as points etc.) Regarding the connection loss, more recent versions of Android will generally try to connect to another saved network if it thinks it's better. If you have your home wifi network saved (i.e. if you checked the automatically connect box when setting up) your device will autonomously move to this network after a short while of use. This is because the Z21 router doesn't have an internet connection (unless you have connected to your home broadband router by network cable). So the android device thinks it is being helpful by moving you to a network with internet connection but this, of course, disconnects your device from the Z21 router. You can stop this happening by going into settings/connections/wifi on your tablet and deleting any saved networks from the list showing other than your Z21 network. If the Z21 network is the only one listed then that's the only one it will automatically connect to. This does mean that each time you need to connect to the internet via your home wifi you'll need to re-enter your network and password details again, and then delete again after, which is a bit if a pain but it should fix your problem. In theory, you should get a pop up on screen telling you there is no internet and asking if you want to stay connected to that network but in my experience that's not always reliable. The other way to fix it is to connect your Z21 router to your broadband router by network cable which will give it an internet connection. If they aren't close enough to each other to do this ghen you can use an ethernet powerline adaptor which cost about £20.