The core of the DIGITAL plus Set-90 and Set-100 professional grade systems is the Command Station LZV100. It coordinates the input devices (Hand Held Controller LH100, LH90, XPA, etc.) and is also responsible for generating the NMRA DCC signal and general data processing. Information is exchanged between Command Station and input devices via a 4-wire cable, XpressNET. The Command Station generates the control signals which are fed to one or more Power Stations (boosters) , which combines them with the necessary power and sends them to locomotive and accessory decoders.
The LZV100 Command/Power Station has a full 5 amp built in power station. boosted output to connect to tracks. Accordingly it only needs a small transformer (15VA), which could be one you already have from a starter set. If you use a more powerful transformer, you can connect the Command Station and the Power Station to the same transformer. Please note however that a minimum of 13 volts AC or 16 volts DC is necessary to power the LZ100. If you are using a full complement of 30 XpressNET devices, the input power should be raised to a minimum of 30 VA.