Taken directly from Tibia Wiki
Its light blinks in a frequency that can be translated to binary, with lights off as intervals and lights on as short or long bits. It takes 10 seconds for each state to start blinking with its code and there are three different states.
The three blinking states display the following binary codes:
01000111 01000001 01001100 01010100 01001000 01000101 01001110
01000001 01000101 01010010 01001001 01010100 01001000
01000010 01010011 01010100 01001000 00110100 01000101
These can be translated to text, resulting in:
GALTHEN
AERITH
BSTH4E
Galthen is a known character of the story, Scarlett Etzel's romantic pair. It's also in his grave that The Missing Piece of the Cube is found. The meaning of the other two words is currently unknown.
The word PLNSTRDR can also be translated from the binary code in the base of the monolith, which is a key word in the Opticording Sphere Quest