SSI -> Arduino

Hi there, has anybody experience with a SSI-signal?
I get the SSI-signal from an absolut encoder and want to read the gray code it's sending.
link for the datasheet: http://gonzo.uni-weimar.de/~mdtl2037/607SSI.pdf
Thanx a lot

see: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1146412852