FiberPlex FOI-4451 - Manual (Page 12)

Other Considerations
Application Flexibility
The units support tail circuit and null modem functions for DCE to DCE or DTE to DTE communications. This
requires two of the same TD unit.
An alternate interface (V.35 or RS‐232) may be installed at the opposite end, allowing the user to create a link
between two electrically incompatible interfaces without requiring a separate interface converter. For more
information, please see the “Optical Compatibility” table.
TEMPEST Versions
TEMPEST is a US Government specification and NATO certification intended to protect valuable and mission
critical information from being intercepted through leaking emanations, including unintentional radio or
electrical signals, sounds, and vibrations. The protection efforts are also known as emission security (EMSEC),
which is a subset of communications security (COMSEC).
The FOI‐4451 and FOI‐4541 have a variant designated with a ‘T‐ST’ suffix which has been rigorously designed
and tested to comply with TEMPEST requirements. These units can easily be visually identified by their silver
finish.
When using an FOI‐4451‐T‐ST and/or FOI‐4541‐T‐ST much care must be taken in both the mating equipment
and especially the copper D‐25 cabling used in such connection. In addition, the power supplies and/or chassis
being uses must have an ‘R’ suffix. For standalone applications, use a PSQ‐4909‐R (or the older PSQ‐4910‐R)
power supply or for a chassis mounted solution use either an RMC‐3101‐R or RMC‐2101‐R chassis. All the
items in the system must be TEMPEST compliant for the system to properly protect the information. Special
TEMEPST compliant cables are available from FiberPlex Technologies, LLC.