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Fleischmann/Roco Z21 Digital Control Center

Read this review from the May 2019 issue of Model Railroader
Fleischmann/Roco Z21 Digital Control Center
Dana used the Z21 app on his Android Smartphone to control MR&T diesel no. 1175.
The app includes several driver's cab screens that can be used when the app is run on a tablet.
The Z21 offers both train and layout control via a touch screen.

Once only available in certain starter sets, Fleischmann/Roco now offers an updated stand-alone version of its Z21 Digital Control Center. Out of the box, the Z21 is an easy-to-use, plug-and-play Digital Command Control (DCC) system that’s simple enough for a beginner, yet has a host of advanced features that will satisfy more experienced DCC users. The Z21 is also easily expandable via multiple connections that support various command bus protocols.

Getting started. The Z21 set includes the command station, a TP Link router with power supply, an 18V main power supply, and a network cable. Note that the set didn’t include a throttle. The main interface with the system is the Z21 app that’s available for free at the Apple App Store and on Google Play. I downloaded the iOS version to an Apple iPad and the Android version to a Samsung S4 smartphone without any difficulty.

The Z21 measures 1.5" x 5.75" x 8.1", and the router measures 1.2" x 5.7" x 6.9". The system should easily fit under most layout benchwork.

Setup was a simple matter of connecting the WLAN port on the back of the Z21 to any of the numbered ports on the back of the router using the supplied network cable and plugging in the two power supplies (the main 18V power supply and a 5V supply for the router).

I also connected our test track leads to the main track output via the supplied screw terminals.

The app. Especially surprising since it’s free, the Z21 app is the most feature-rich model train control app that I’ve used. The app is intuitive and allows touchscreen control of decoder-equipped locomotives, cars, and accessories.

The app comes preloaded with information for several Fleischmann Roco locomotive models. There are also menu screens for controlling Roco WiFi-camera-equipped locomotives.

Adding a new locomotive to the roster is straightforward, including setting up specific function controls. I could also take and upload a photo of the locomotive to use for its roster entry, as I did for Milwaukee, Racine & Troy no. 1175, shown in the screen shot above.

There are configuration variable (CV) programmers for Programming on the Main (POM), or for using a dedicated programming track. The Z21 also supports RailCom, so it will read back information from a RailCom-enabled decoder even if in POM mode.

The main throttle controls are responsive, featuring large, easy to see function buttons. I especially like that one’s entire locomotive roster is displayed along the bottom of the screen, so with one touch of a finger I can switch between locomotives or consists.

Depending on the version of the app, multiple-unit consists are referred to as Multi-Traction or Trains in the main menu. Prior to setting up a consist, I measured each locomotive’s speed at various steps over a set distance. I then recorded this information under each locomotive’s roster entry. When I used those locomotives in a consist, the Z21 automatically speed-matched them. This was a lot less tedious than having to speed match the locomotives via speed tables and CVs.

An advanced consist can also be set up by simply making a roster entry for the advance consist address and programming the locomotives accordingly.

When used on a tablet, the app includes eight driver’s cab downloads that provide an engineer’s view of a specific prototype. The controls can also be manipulated via touchscreen, turning the Z21 into a locomotive simulator.

All the included cabs were for European steam, diesel, and electric prototypes.

There are additional menus for configuring a track schematic, including icons for switch points and signals. When coupled with stationary decoders or other controls, these devices can be triggered by touching the appropriate icon on the screen. 

The back of the Z21 digital control center shows the various connections supported. There are also two more X-Bus sockets on the front of the unit.
The system works with Roco Multimaus wireless and Wi-Fi throttles.
Expanding the system. Those who wish to run trains with traditional handheld throttles needn’t worry. The Z21 command station has three X-Bus sockets for XpressNet-compatible devices, including tethered and wireless throttles from Lenz and Roco’s own family of Lokmaus and Multimaus handheld throttles. There’s also one L-Bus connection for Digitrax LocoNet-compatible throttles. During testing, we ran trains using Lenz and Digitrax throttles and an iPad running the Z21 app simultaneously.

The Z21 is a fully expandable system that includes connections for feedback modules (R-Bus) and additional track boosters (B-Bus). The former are used for setting up detection and signaling systems, and the latter is helpful for dividing a larger layout into power districts. There are separate screw-terminals for a sniffer bus and an isolated programming track.

This latest version of the Z21 also includes a CAN bus socket, making it compatible with ZIMO MX32 handheld throttles.

The Fleischmann/Roco Z21 features reliable, plug-and-play performance. Its user-friendly app, support for multiple command bus protocols, and expansion options make it a standout DCC system.

Price: $466.83
Modelleisenbahn München GmbH
Kronstadter Straße 4
81677 München
Distributed in North America by
Heartland Hobby Wholesale
6929 Seward Ave.
Lincoln, NE 68507
• 3A output
• Additional boosters and feedback modules available
• Built-in computer interface
• Built-in updater for ZIMO sound decoders
• Firmware can be updated via a PC with an internet connection using free Z21 Maintenance software
• Includes 18V main power supply
• Includes TP Link router
• Manage up to 9,999 locomotive decoder addresses and up to 2,044 turnout decoder addresses
• Supports 14, 28, 128 speed steps
• Supports multiple command bus options including LocoNet and XpressNet
• Works with Digital Command Control and Motorola formats
• WiFi control with download of free iOS or Android Z21 app

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