The TCF-90 is a compact sized, high-speed, RS232 to fibre optic converter that extends RS-232 transmission from 15 meters to 5 km (TCF-90-M multimode) or 40 km (TCF-90-S, singlemode) without the requirement for external power. The TCF-90 is designed to get power from the attached serial port.

The TCF-90 isolates connected serial devices from dangerous increases in ground potential, ground loops, and electrical EMI/RFI noise. This greatly reduces RF radiation and susceptibility to electromagnetic radiation to improve data integrity.