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NAND Logic Gate

A DC term that means the voltage is lower than 0.
You can have it plus or minus the zero point

The National Model Railroad Association in the USA is the largest organization devoted to the development, promotion, and enjoyment of the hobby of model railroading. The NMRA was founded in 1935 in Milwaukee, Wisconsin in order to provide a service to the hobby of model railroading. It is responsible for defining the standards for DCC control systems. See: NMRA website

An MRR layout control bus being developed to complement DCC and other traction methods and to control accessories. It is traction and transport agnostic. Developed by OpenLCB and now known as LCC. See: OpenLCB website.

NOR Logic Gate

Nor is a gate term used to describe logic components.
NOR gate (NOR = Not OR)
This is an OR gate with the output inverted, as shown by the 'o' on the output.
The output Q is true if NOT inputs A OR B are true: Q = NOT (A OR B)
A NOR gate can have two or more inputs, its output is true if no inputs are true.

Types of transistor: There are two types of standard transistors, NPN and PNP, with different circuit symbols. The letters refer to the layers of semiconductor material used to make the transistor. Most transistors used today are NPN because this is the easiest type to make from silicon. If you are new to electronics it is best to start by learning how to use NPN transistors.
See also: Transistors

Node Variable a CBUS term referring to a value which controls the overall behaviour of a node. For example in the CANACE8C module, taking an input low generates an On event, when that input returns high this normally generates an Off event. This behaviour can be modified by one of the NVs where a set(1) bit within the NV will cause the associated Off event generation to be suppressed.