Digi Connector C/X and EPC/X Host Adapter for EIA 232 Modem
C/X and EPC/X host adapters and C/CON concentrators have been designed so
that the synchronous ports can support either EIA-422 or EIA-232 line levels.
Eight-Wire Synchronous Modem wiring allows concentrators to be installed in
remote locations and connect to the host adapter via EIA-232 or EIA-422
synchronous modems, DSUs/CSUs, frame relay adapters, fractional T1s or ISDN
terminal adapters. The EIA-232 synchronous modem cable is a twisted pair cable
with a male HD-15 (high-density DB-15) connector at one end and a female DB-25
at the other end.
For more information: http://digi.com/products/multiport%20serial%20cards/dox/apxr.pdf