Roco Z21 Initial Setup Experiences [Starting From Zero]

[pbunter]

A few things I learned when initially setting up my Roco Z21 (black) that I purchased in early February 2021 from a US dealer. Hopefully present and future Z21 owners may benefit from my experiences. If you find something that does not jive with your experiences, please let me know so I can update this post. Note that I have the US version (model 10822) so my experiences come from that perspective. https://www.z21.eu/en 

The short version:

 

1.  The Z21 manual in the box (and online) is out of date - at least with respect to the associated smartphone app.
     An update is in the works. In the meantime, the manual for the Z21 XL is up to date with respect to the "Z21" app.

 

2.  There are two versions of the Z21 app in the Apple app store: "Z21" and "Z21 Mobile".
     Choose the "Z21" app if you have iOS 11 and above or Android 5 and above.
     Choose the "Z21 Mobile" app for older versions of iOS and Android.

 

3.  The "Z21 Maintenance" iPhone app allowed me to update the Z21 to firmware v1.33 but it didn't show me v1.40.
      I needed the Z21 Maintenance Tool v1.15 (Windows only) to get the latest firmware v1.40.

 

4.  My TP-Link wifi router is model TL-WR841N(TPD) and only accepts EU region firmware and not US region firmware.

 

5.  I can use the "Z21" app to read CVs from a loco on the programming track, but I wasn't expecting the loco to move forward a little bit with each read.

The long version:

 

1.  My Z21 seems to have been manufactured in 2018-19 or so? The Z21 had firmware version 1.32 (current is 1.40) and the TP-Link wifi router firmware was from 2018. Unfortunately, the manual appears to be somewhat out of date too. It almost perfectly matches one I found online dated 2014.

 

I sent an email to Roco asking if/when they plan to update the manual. I received a response within 2 days indicating that an update to the manual is coming but it may be awhile yet. With respect to the "Z21" app, the manual for the Z21 XL (model 10870) is up to date. https://www.z21.eu/en/products/z21-xl-series 

2.  There are two Z21 apps in the Apple app store for iPhone: "Z21" and "Z21 Mobile". Both are developed by Modelleisenbahn GmbH but if you look at the version history for each app, development of the "Z21 Mobile" app ended two years ago while the "Z21" app was updated several times already this year (March 2 being the latest). The (outdated) Z21 manual only mentions the "Z21 Mobile" app but that's the wrong choice - at least for my version of iPhone. The FAQ identifies the differences (https://www.z21.eu/en/faqs-support/questions-answers, question 1.3).

3.  I didn't spend much time exploring the Z21 Maintenance app other than to upgrade the Z21 firmware to version 1.33. Although version 1.40 was already available, I didn't see it as an option via the app. Maybe I didn't give it enough time? Firmware 1.40 is available via the (Windows-only) Z21 Maintenance Tool v1.15 so I downloaded that tool and upgraded the Z21 to 1.40. https://www.z21.eu/en/downloads/software-tools 

4.  Updating the firmware for the TP-Link router was not as simple as I'd hoped. If you try to upload the latest firmware for the US region, installation fails with the wonderfully helpful message: "Error 4503 - The uploaded file was not accepted by the device". The code in parenthesis after my router's model number (printed on the bottom of the router) is "TPD" which I assume has something to do with a region but nowhere is it defined on the TP-Link website. However, since Roco is based in Austria, I decided to try the EU region firmware from the Austria (Österreich / Deutsch) TP-Link website and it worked. TP-Link tech support was hilariously ineffective[1] except to tell me, after the fact, that TPD is for Germany.
https://www.tp-link.com/de/support/download/tl-wr841n/#Firmware 

 

You don't *need* to update the router's firmware but I figured I could do it at least once at the beginning so I can have the latest security upgrades. The new firmware version is: 0.9.1 4.17 v0001.0 Build 200903 Rel.58674n (dated 2020-09-03). I don't plan to do it again.

 

[1]  I used TP-Link's online contact form to ask how to find the right firmware for my model. In the form I stated the router hardware version and error message. They responded the next day (pretty good) asking what is the router hardware version and error message - which were both clearly given in a nicely formatted table at the bottom of the email they sent me. I knew I wasn't going to get much help from them after that.

5.  I learned that when using the "Z21" app, reading CVs while on the programming track causes the loco to move a small amount forward. I was not expecting this and after reading about 20 CVs I suddenly noticed that the front truck of the loco was entirely off the track. Oops. Gotta keep an eye on it.

 

- - - Paul
 

[chadbag]

2 hours ago, pbunter said:

5.  I learned that when using the "Z21" app, reading CVs while on the programming track causes the loco to move a small amount forward. I was not expecting this and after reading about 20 CVs I suddenly noticed that the front truck of the loco was entirely off the track. Oops. Gotta keep an eye on it.

 

 

Hi Paul. Thanks for your experience.  I intend to eventually get one of these to test with mty Throttle (and later minimal train control) app I am writing.

 

The above experience is similar to what I have seen with most command stations.  Reading or writing the CV for me tends to cause the locomotive to jerk or move a little.  I've noticed this when programming on a programming track with my D&H programmer.   I am assuming it is on purpose to give you feedback from the  locomotive that it got your request 🙂  ...  But I don't know the technical details of why it happens.

[Madsing]

I am also using a Z21 and I am very happy with it. I have not upgraded to firmware 1.40 yet (I am in no rush, there is no new feature that I need).

Reading CVs makes the locomotive move, this is normal. This is actually due to the decoder, not the Z21. The reason comes from the DCC standard. The decoder sends information back to the control station by loading the DCC signal (= consuming current) at very precise time slots. That current consumption is measured by the control station that rebuilds the value read bit by bit. The only way the decoder can consume current is by connecting a load. In a motor decoder, this means connecting the motor, which then moves a tiny bit. That’s also why many lighting decoders cannot provide feedback, they have no real load to connect to the bus.

 

[pbunter]

Thanks Madsing! That detailed description is just what I was hoping for. I am also happy with my Z21 and look forward to giving it a good workout.

[inobu]

The jerking is normal. This is what's happening.

 

The programmers are set up to prevent destroying a decoder that may be installed incorrectly. On start up it sends out a little bit of

current for a few milli seconds on the programming track. Because the duration is so fast and short it wont blow the decoder if sometime is wrong.

The decoder needs the current flow to power up long enough to create a response to the programmer. It is the DC motor that draws that current.

Each reading of the CV is the decoder powering up and responding. Because the motor is connected to the decoder

it will spin momentarily hence the movement. The key to reading the CV's on the test track is the sustaining of current draw.

 

Whenever I test a plain decoder I will connect a LED to the orange and gray motor lead and the LED will draw the current during the read. This

gives me a visual on an uninstalled decoder for example.

 

Inobu

[pbunter]

I've seen DCC test tracks that have bumpers at both ends. That would prevent falling off the rails. I assume then that trying to move while already at the bumper does not cause any trouble for the motor?

 

- - - Paul

[chadbag]

I put bumpers on both ends of my test track.  No, as long as you don't leave it running against the bumper for a longer amount, the small jerks from programming it won't hurt the motor if it is up against the bumper.

 

ETA:  My "bumpers" are just big blobs of silicone that has hardened 🙂

 

Edited March 5, 2021 by chadbag