Just out of curiosity What are these used for? i know in other older machines they use them for wap etc
In S3000's, the fiber I/O card is used for Fiber Loops for a UC or ABSC (Universal Controllers)
UC's and ABSC's can be used for Progressive Controllers, Sign Controllers (up to 6 monitors at once!) and NAP (and WAP) LAN servers for EGM banks.
The 3rd Optic port on the card (and the secondary Optic ports on UC's, IPC's and ABSC's) are for older remote sign controllers. It enables you to branch off the Optic signal if needed. Output only on the I/O cards, Cloned (secondary) loop on the IPC's, UC's and ABSC's.
Hope this helps!