Description: A bit array that contains the value of the
front panel LEDs of the fan trays. This is
a packed bit string; each LED is encoded into
4 bits (a nibble). The first nibble is stored
in the high order bits of the first octet. The
second nibble is stored in the low order bits
of the first octet etc. The current mapping is 
            that the first four nibbles are reserved, 
            the fifth nibble has the value of the 
            'annunciator', and the 'normal' LEDs start with 
            the sixth nibble. If the LED values are not
available, a zero length string is returned. The
following shows the meaning of each bit (bit 0 is
the least significant bit) when it has a value
of one:

  bit  meaning
  ---  -------
   0   red light
   1   blue light
               2   purple light
               3   blinking
   4   reserved