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