SoundTraxx Coach Lighting Decoder Users Guide - Manual (Page 6)

SoundTraxx Lighting Decoder User’s Guide Page 3
Programming the CVs
What is a CV?
CV stands for Configuration Variable, which is the industry-adopted term for a
decoder’s user-programmable memory locations. CVs allow you to customize
individual decoder properties such as the address, momentum, throttle
response, and much more. Once a CV has been programmed, the setting
will be permanently remembered even after the power has been turned off. A
CV can be modified as often as necessary by simply reprogramming it with a
new value.
With the large number of CVs available, first inspection of the available
options may cause confusion and little panic! Relax. As you have already
seen the decoder has been shipped with all CVs pre-programmed so you can
begin using your locomotive immediately without having to worry about what
adjustments to make.
The following paragraphs break the decoder’s CVs into various subsystems
so it is only necessary to change a few CV’s at a time. As you become
comfortable with it’s operation, move onto a new section and begin exploring
the options and capabilities found there. For more technically inclined users,
detailed information on any CV can be found in the Coach and Caboose
Lighting Decoder Technical Reference.
Bits and Bytes
One of the most confusing aspects of programming a CV is figuring out what
all the different bits, bytes and x’s found in the various decoder manuals
mean. The problem is compounded further by differences in each command
station manufacturer’s user interface. For users unfamiliar with such terms, a
short math lesson (ugh!) is in order before proceeding:
Each decoder CV stores a numeric value that can be represented in one of
three forms:
Decimal - This is the form everyone is familiar with and we use in our day-to-
day lives. Numbers are represented as a sequence of digits composed of the
numerals 0,1,2,3,4,5,6,7,8, and 9.
Hexadecimal - Also referred to as simply “hex”, this is a more specialized
number representation that, in addition to 0 through 9, also uses the
characters A-F. It has the advantage that a given decimal number can be
more compactly represented. For example, the decimal number 127 converts
to a simple 7F in hex (one less digit). This allows user interfaces with a
limited number of digits (i.e., the LCD on your cab) to display a wider range of
numbers.
Binary - Binary numbers get their name from the fact they use only two
digits 0 and 1 called ‘bits’ and is the fundamental number system used by all
computers including the ones found inside a digital decoder. Because there
Basics of Programming