This Oracle tutorial explains how to use the Oracle/PLSQL HEXTORAW function.
HEXTORAW(x)
converts the character x containing hexadecimal digits (base-16)
to a binary number (RAW).
The syntax for the Oracle/PLSQL HEXTORAW function is:
HEXTORAW( char )
char is the hexademical value to convert to a raw value.
SQL> select hextoraw('7E') from dual;
HE
--
7E
SQL>