The Z21 system from Roco not only makes it easy for you to find the optimal digital entry into model railway controlling but through its different versions, it is also perfect for model railway experts. Each Z21 central unit features at least two X-Bus, one R-Bus, one B-Bus and one LAN socket. All systems can be used for AC and DC track layouts, as they can send both a DCC and an MM signal.
The DCC data format for all locomotive and turnout addresses is preset in the Z21 versions. Only in the Z21 App, more precisely under the submenus "Settings" (under "locomotives" or "signal box"), this can be changed per address to the alternative digital format "Motorola"!
Here is a detailed list of the different features of the Z21 system versions in comparison.
Z21 black for experts (full version)
The black Z21 model railway control captivated model railway professionals with its additional connections and functions, such as: the CAN bus, the L-Bus (LocoNet), the sniffer bus as well as its own track programming connection.
This allows the Z21 control unit to be connected to other panels such as the multiZentralePRO (as a slave) via LocoNet (as a master). A detailed list of which control panels you can use with LocoNet or which CAN devices you can use with the Z21 control can be found here
In comparison with its “smaller brothers” the black Z21 control does not only differ in hardware but for example, you can also update Zimo decoders and adjust the track voltage individually.
The main voltage (actual voltage on the track) is generally always 1 volt lower than the nominal voltage of the power supply used at the moment of operation.
For example: Power supply 10851 = 20 V nominal voltage
The main voltage at the track = 19 V
With the black Z21®, the main voltage can be adjusted individually via the Maintenance Tool (LINK to FAQ "Maintenance"). The highest possible value is 23 V (assuming a 24 V power supply), the lowest possible value is 13.5 V.
Especially for large-scale railways (garden railways), a higher main voltage can lead to a more stable signal on the model railway layout. It should be noted, however, that everything also depends on the proof voltage of the built-in decoder in use.
For smaller gauges (track TT, N, Z ...) or older locomotive decoders, in turn, a reduced main voltage can be useful, since these decoders often also have a lower proof voltage.
In addition, it is already equipped from factory with a powerful power supply of 20 V / 2.6 A (item number 10851), as well as a separate wireless router and can easily be controlled via a manual regulator, Z21 App or PC.
Z21 white for beginners (was available as a starter set before 2017)The white Z21 model railway control is the "little brother" of the black Z21 control system and was part of the older Roco Starter set which was already available before 2017. It is equipped from factory with a weaker power supply of 18 V / 2 A, and a wireless router and therefore can also be controlled via a manual regulator, Z21 App or PC.
Z21start for beginners
The Z21start model railway control is also a fully equipped central control unit. With the attached multiMaus you can easily control your locomotives, switch points, program and also read CVs. The Z21start is RailCom compatible but controlling via WLAN and LAN with the Starter Set is not yet possible.