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Showing posts with label CV 29 bit switch configuration bits:. Show all posts
Showing posts with label CV 29 bit switch configuration bits:. Show all posts

Sunday 16 October 2022

CV 29 bit switch configuration bits::

Confusion can arise as CV’s can be expressed either as a decimal value between 0 and 255, or as a sequence of bits:, expressed as eight switches that may be switched “ON” or “OFF”.  

Further confusion arises by referring to the bits: as in 1 for ON, a better method is use the decimal number for the relevant bit: when ON.

For example referring to bit:0  as 1 = ON as in the usual manner appears acceptable.

But, then referring to bit:1 as 1 = ON, totally confuses the issue as the total is not 2 but decimal 3, arrived at by adding bit:0 and bit:1 together.

Much simpler when referencing a bit: is to discard the use of 1 as in ON, and refer to the decimal value of the bit: as ON.

Makes more sense and simpler to add together all the ON decimal values of each bit:, that have been set, and to reach a total value that a human can comprehend. 

Each of the eight bits is allocated a decimal value based on the binary scale. 

For example 00000010, which is totally meaningless, until it is deciphered, it is actually decimal 2.

Further confusion can arise, as Lenz for example, start numbering them from 1 to 8.




As an attempt to unscramble the confusion surrounding bits: in a bit switch CV, the PCB above was constructed as a visual aid when setting individual bits:  


Using CV 29 as an example, bit:1 and bit: 5 are ON, which gives a decimal value of 34, 28/126 speed steps and Long Address. 

Note:
The value of 126 is not a typo, the often quoted figure of 128 is a figment of imagination!

The above should be self explanatory..........


 CV 29 Decoder configuration.

The example used was for CV 29, the same principle can be used for any CV that requires individual bits:, setting.