>>-C2D(string--+----+--)---------------------------------------><
               '-,n-'      

returns the decimal value of the binary representation of string. If the result cannot be expressed as a whole number, an error results. That is, the result must not have more digits than the current setting of NUMERIC DIGITS.

If string is null, returns 0.

C2D('09'X)      ->        9
C2D('81'X)      ->      129
C2D('FF81'X)    ->    65409
C2D('')         ->        0
C2D('a')        ->      129     /*  EBCDIC  */

If you specify n, the string is taken as a signed number expressed in n characters. The number is positive if the leftmost bit is off, and negative, in two's complement notation, if the leftmost bit is on. In both cases, it is converted to a whole number, which may, therefore, be negative. The string is padded on the left with '00'x characters (note, not “sign-extended”), or truncated on the left to n characters. This padding or truncation is as though RIGHT(string,n,'00'x) had been processed. If n is 0, C2D always returns 0. If you do not specify n, string is processed as an unsigned binary number.

C2D('81'X,1)      ->     -127
C2D('81'X,2)      ->      129
C2D('FF81'X,2)    ->     -127
C2D('FF81'X,1)    ->     -127
C2D('FF7F'X,1)    ->      127
C2D('F081'X,2)    ->    -3967
C2D('F081'X,1)    ->     -127
C2D('0031'X,0)    ->        0

Implementation maximum: The input string cannot have more than 250 characters that are significant in forming the final result. Leading sign characters ('00'x and 'FF'x) do not count toward this total.