Power supply
The XnTcp can obtain its power directly from the XpressNET bus, keeping however in mind that it draws approx. 60 mA and exceeds thus the 20 mA limit per node set for in the XpressNET specifications (PDF file).
Before plugging the XnTcp into the XpressNET bus, make sure that the current drawn by the XnTcp and by the other devices connected to the bus does not exceed the maximum load supported by the Command Station (Consult the documentation accompanying the Command Station and the other devices).
Alternatively, the XnTcp can be powered by an external power supply. This can be any source of unregulated DC (e.g. a DC model train power-pack) ranging from 7 to 30 Volts (if the diode and the resistor shown in the scheme are not installed) or from 12 to 30 Volts (if the diode and the resistor are installed).
The lower the voltage, the better, since each Volt in excess of 7 results in the dissipation of additional 60 mW. Using an external power supply is highly recommended if the Auxiliary Outputs of the XnTcp are employed.
The power supply must be equipped with a center positive 2.1 mm. barrel power plug (e.g. DigiKey CP3-1000-ND).
XpressNET is a trademark of Lenz Electronik, Gmbh