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Here is a list of terms with short descriptions and links to full pages. This should help in reminding you what all the DCC/Train terms mean.

[edit] A

[edit] Accessory Decoder

A decoder other than a mobile decoder. Typically used for activating turnouts, operating signals, other lighting or animation.

[edit] Address

A number assigned by the user to a particular mobile or stationary decoder. The DCC system uses the decoder address to send commands to the appropriate loco or accessory. The decoder address is stored permanently in configuration variables.

[edit] Address - Range

Various DCC systems have a certain number of addresses that it can handle. Lower-end DCC systems can be as low as 6 addresses. Average systems usually handle between 99

[edit] Advanced Consist Control

[edit] Analog Operation

[edit] B

[edit] Back EMF

A counter ElectroMotive Force generated in rotating machinery. It resists current flow in the machine, and limits it's speed. In DCC, the Back Electromotive Force is monitored by the decoder, which uses that to maintain a steady speed under varying load conditions, such as grades. Sound decoders can use the BEMF to alter the sound, such as the sound of the motor working to climb a grade, louder, harder chuffs, or the rod noise as a steam locomotive drifts downgrade.

[edit] Block Detector

[edit] Booster

A device which takes the signal generated by the command station, and modulates a Direct Current voltage with it. The resulting waveform is fed to the track. The signal on the track is completely digital, containing all the data needed to control various decoders.

[edit] Bus

A specific group of electrical wires that carries a particular group of voltages or signals.

An example would be the power bus that supplies voltage and current to the track, running in parallel with the track and connected at multiple points using feeders.

Another example would be something like the LocoNet, which connects various devices together into a network, allowing communication between devices.

[edit] Buss

Verb: To kiss. Really has nothing to do with DCC or electricity.

[edit] C

[edit] Cab

In DCC, they are not called cabs. That is a DC term.

The part of a DCC system that comprises the user interface. This is how the user controls locomotives and other aspects ot the system. A DCC system may have one or more cabs.

[edit] Cab Bus

The bus that connects cabs to the command station.

[edit] Command Station

A device which is connected between the throttle and the booster.

The command station takes the signals generated by the throttle(s), and creates a data stream which is then routed to the booster(s). One command station can supply data to a number of boosters. It also handles input from multiple throttles.

Many systems incorporate the command station and booster in a single package.

[edit] Command Control

Command Control manifested itself in many ways. The underlying principle was independent control of a number of locomotives. The basic system worked not by varying the track power to control the motor, as in analog systems with blocks, but by using tones or high frequency signals superimposed on the track voltage. The earliest example would be the Lionel Electronic Control system, from 1946.

There were a number of systems offered over the years, from Lionel and General Electric to small companies or hobbyists making them. They were all analog and incompatible with each other. The first Digital system was the Hornby Zero 1 system of the late 1970s. Command Control never gained a significant share, nor did any one system, as they were expensive, limited, and incompatible.

[edit] Configuration Variable

[edit] Consist

In DCC, two or more locomotives that are operated as a unit. In general railroading, the makeup of a train.

[edit] Consist Address

The unique address by which a consist can be accessed.

[edit] Continuous Load

The maximum current that a decoder can supply to a particular output for an extended period of time without causing damage to the decoder.

[edit] Control Bus

The control bus is the bus connecting the command station to the boosters. The signals on this bus are low level DCC packets which are then amplified by the boosters for delivery to the decoders.

[edit] D

[edit] Decoder

The end consumer of the DCC signal. A decoder responds to DCC commands directed to its specific address to perform specific functions.

[edit] Decoder Assisted Consisting

[edit] Digital Command Control (DCC)

Command Control is a method of controlling locomotives using various schemes, which typically employs a high frequency signal (from audio to radio frequencies) to control a decoder. Most Command Control systems are analog in nature, often employing a constant direct current voltage with a higher frequency, low voltage signal superimposed on it.

Digital Command Control breaks from that model, employing a pure digital signal. There is no analog component on the rails. The decoders are purely digital, not analog in nature. Doing so eliminates many of the problems or limitations inherent with analog systems. The NMRA has defined Digital Command Control, but also allowed room for future expansion and enhancement in the DCC Standard.

[edit] Directional Lighting

[edit] Ditch Lights

[edit] Dither

A feature in some mobile decoders to improve low speed performance by providing additional power to the motor at low speeds.

[edit] Dropping Resistor

See Series Resistor

[edit] E

[edit] EFX

[edit] Encoder

[edit] Extended Addressing

[edit] Extended Packet Format (EPF)

[edit] F

[edit] Function

A particular output (other than the motor control) by which a DCC decoder can provide an action. An output to turn a light on and off with a mobile decoder is an example of a function. In sound decoders, the ability to produce a particular sound pattern is also considered a function.

Some functions may control more than a single output. For example, F0 generally turns the headlights of an engine on or off. If a decoder is programmed for directional lighting, the output for the forward light will be activated if F0 is on and the direction of travel is forward, and the the rear light if F0 is on and the direction is reverse.

Functions are controlled by sending commands to the specific decoder. Modern DCC systems allow up to 28 distinct functions to be controlled. Older and limited systems may provide significantly less. The number of supported functions vary by decoder.

[edit] Function Current

[edit] Functional Remapping

[edit] G

[edit] Gyra Light

[edit] H

[edit] Heat Shrink Tubing

A polymer tube which will shrink when exposed to heat (from a heat gun). Typically used to insulate electrical connections, in place of electrical tape. Various diameters are available for this purpose.

[edit] J

[edit] JST Socket

[edit] K

[edit] Kick Start

[edit] L

[edit] Lamp

[edit] LED

Light Emitting Diode.

A semiconductor diode manufactured to produce light when current flows through it. It works the same way as a diode, but is designed and made to maximize the light output from the junction of the positive and negative materials.

By changing the elements used in the doping process (which turns an insulator into a semiconductor), the colour of the light produced can be altered. When encapsulated with plastic, the colour of the plastic is chosen to maximize the light output by acting as a filter.

LEDs are very sensitive to current and voltage, so they must be used with a series resistance to reduce the voltage and limit the current. The colour can also be an indicator of how much current the device will tolerate.

[edit] M

[edit] Magic Smoke

There is a legend concerning electronic components (ie DCC decoders, LEDs, etc.). It states that every electronic component works because it is filled with a 'magic smoke.' If you exceed the electrical limitations of the device, you will let the 'magic smoke' out, and it will fail to work anymore. Of course, there is no such thing as 'magic smoke.' However, electrical components tend to fail with a puff of smoke, and a distinct smell that only failed electrical components have.

[edit] Mars Light

[edit] Medium Plug

[edit] Mobile Decoder

[edit] Motor Current

[edit] Motor Drive Frequency

[edit] N

[edit] NMRA JST Socket

[edit] NMRA Medium Plug

[edit] NMRA Small Plug

[edit] O

[edit] Operations Mode

[edit] P

[edit] Packet

[edit] Paged mode

[edit] Peak Load

The maximum current that a decoder can supply to a particular output for an brief period of time without causing damage to the decoder.

[edit] Power Booster

[edit] Power Bus

The bus that connects the outputs of a booster to the track or accessory decoders

[edit] Power supply

A power supply is an electrical device which supplies power to another device. Typically they convert the input voltage to another voltage, as well as providing regulation and overload protection. In DCC they step down the house voltage from 120 or 240 volts to 12 to 20 volts. The output may also be rectified (converted) to direct current from the alternating current input.

Power supplies can range from very simple to very sophisticated, depending on the cost and the application. An example of a simple power supply would be a "wall wart", or brick, where the unit may be a block that connects directly to the power source, or a small box that has a line cord to connect it to a power source, with another cable providing the output power.

[edit] Programming

[edit] Programming Track

A track set aside for programming locomotives. It may or may not be part of the layout. In many cases, the programming track is connected to terminals labelled "program" on the booster, instead of the usual terminals for track power.

If the track is on the layout, it must be isolated from the rest of the layout, so that a locomotive will not accidentally bridge the programming track with the rest of the layout (and its power). Doing so will damage something, usually the booster.

[edit] Q

[edit] Quiet Drive

[edit] R

[edit] Real FX

[edit] RJ12 Connector

The six conductor connector (sometimes only the center two or four are used) that is typically used for connecting telephone equipment. Widely used in DCC for bus connections and cab plugins.

[edit] Rotary Beacon

[edit] Rule 17 Headlight Dimming

[edit] S

[edit] Series Resistor

A resistor installed in series with a load, whose purpose is to limit the current. Current flowing through the resistor will result in a voltage being developed across the resistor. This is the voltage drop. A typical application is to limit current flow in an LED, or to create a voltage drop for a lamp that would be destroyed if exposed to full voltage.

[edit] Service Mode

[edit] Silent Drive

Another term for High Frequency or Supersonic drive. The motor is driven by a very high frequency signal that cannot be heard. Otherwise the buzzing noise it produces may be annoying.

[edit] Silent Running

[edit] Small Plug

[edit] Speed Steps

[edit] Speed Table

[edit] Stall Current

The current that an electrical motor draws when its shaft if prevented from moving. This is typically the highest current a motor will draw. The stall current of a locomotive should be less than the peak current capacity of the decoder that is fitted.

[edit] Start Voltage

[edit] Strato Light

See rotating beacon.

[edit] Strobe Light

[edit] Supersonic Drive

A technique that employs a high frequency signal to the drive the motor. The motor voltage output from the decoder is switched on and off rapidly. As the throttle is opened, the ratio, or duty cycle changes. At full throttle the voltage will be applied 100% of the time, whereas at half speed, the voltage would be switched on only 50% of the time. The amplitude of the voltage never changes, just the duty cycle.

Since the frequency is very high, any buzzing from the motor cannot be heard. Some decoders offer the ability to adjust the frequency, to provide adjust should the motor noise be a problem.

This is the same technique as pulse power used with analog systems. To overcome friction in the motor, a full voltage pulse is rapidly applied by the analog power supply, the pulse rate increasing as the throttle is opened.

[edit] T

[edit] Throttle

See cab.

[edit] Track Bus

[edit] Transponding

[edit] U

[edit] Uploadable Speed Table

[edit] V

[edit] Vmid

[edit] Vmax

[edit] W

[edit] Wireless Cab

[edit] Wireless Cab Base Station