Clear-Com EF-701M - Manual (Page 37)

E F - 7 0 1 M I N T E R F A C E 2 - 1 5
Just as with analog cable, the longer the fiber-optic cable, the more signal degradation
occurs. Cable splices and connectors also contribute to overall path loss. Performance is
dependent on the modem, the cable, and the selected wavelength. Single-mode fibers can
carry signals over much longer lengths, though the equipment is more costly, in part due
to the use of lasers rather than LEDs as the light source.
For dedicated use, Clear-Com has found that the FiberOptions 249B series (multimode,
single channel) works well for most single channel applications. Range is up to 2.5 km
(1.55 miles) with negligible signal loss at 1 km (0.62 mile) or less.
OTHER METHODS
Any device that can accept 4-wire audio and RS-422 data and convert them in either
direction could be considered ideal for use with EF-701M units. There are a number of
choices for fiber-optic “modems” that meet this criteria. Selection is much more limited
among computer networking devices and audio codecs typically used with ISDN.