Basics of Programming
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, sound volume 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 DSD 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 sound 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 Tsunami 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
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