The RA-64/128K Rate Adapter allows low speed async RS-232 DTE equipment
to transmit over a high speed 16k, 64k or 128k sync communications link.

The RA-64/128k devices are used in pairs, one at each end of the communications
link or in multiples as when used in a multi-point or broadcast communications
link. The RA-64/128k will support bi-directional or simplex data transmissions.

The RA-64/128k supports async character length of 8, 9, 10 and 11 bits,
including the start and stop bit. The asynchronous interface is RS-232 and
supports data rates of 1.2k, 2.4k, 4.8k, 9.6k, 19.2k, 38.4k, 57.6k or 115.2k. The synchronous
data interface rate must be set at 16k, 64k or 128k and will support data
interfaces of X.21, RS-422, RS-530 or optional V.35.

The RA-64/128k will support V.35 by ordering the unit under part number
147000. The V.35 data interface will support both the old V.35 (+/-0 .5 volts) or
newer V.35 (ITU recommendation V.11) ground to +3.8 volts. A DB-25 male to
V.35 male 6 foot adapter cable is required for V.35 termination. The cable
should be ordered under part number 712005.

The RA-64/128k derives its power through the async and sync data interfaces.
The device utilizes leading edge technology for reliable, low power
operation. The user should insure that the RA-64/128k has a minimum of
three synchronous control signals available for proper operation.

The RA-64/128k is housed in a sturdy metal enclosure