Fiberplex FO1-2971-RS-ST is an Isolator for Telephone (POTS) Exchange Side, Singlemode ST Optics, and RFI Suppressed. Packed in rugged military-style metal enclosures, the FOI-2971 and FOI-4972 analog-to-fiber converter devices provide complete electrical isolation for 2-wire telephone communications. The FOI-4972 supports standard analog phones, STU-III (secure telephone unit) phones, STE (secure telephone equipment) phones, fax machines, and modems and supports Caller ID. Fiber optic cable offers much longer transmission distances than traditional telephone line cord wiring. Multimode optics on the units can extend the distance to 2km, while singlemode optics can further extend the distance to 20km.
The analog-to-fiber converter units can be used in areas of high electrical noise or in and out of RF shielded enclosures. The fiber optic cable is not susceptible to interference caused by impulse noise, crosstalk, or EMI. Privacy of communications is also enhanced because the fiber optic cable does not radiate any emissions. FiberPlex recommends "R" units for high security applications because the units have added filtering and shielding for RFI suppression.
FOI version units can be mounted in several redundant powering chassis; rack and wall mount options including Tempest and NEMA alternatives.
A typical link consists of an FOI-2971 connected to the POTS line and an FOI-4972 at the subscriber's phone with a duplex fiber optic cable between them.