4RF Aprisa XE User Manual - page 143
Configuring the Traffic Interfaces | 141
Aprisa XE User Manual
DTE to DCE Mode 3: RxC (X.21) - 40 kbit/s overhead (Pass-through clocking)
DTE clocks
used
DCE clocks
used
Clock passing
Comment
RxC
RxC
40 kbit/s of overhead used to
transport RxC from the DTE to
DCE.
Preferred option for X.21.
DTE to DCE Mode 6: RxC RxC - No overhead (Primary/ Secondary Master clocking)
DTE clocks
used
DCE clocks
used
Clock passing
Comment
RxC and
TxC
RxC and
TxC
The DTE XTxC is derived from
the RxC and is used to generate
the terminal external clock.
The DCE generates RxC and TxC
from the terminal clock.
HSS becomes the External master
clock, avoiding explicit clock
passing, but foregoing the use of
passing a clock in either direction
(Modes 1, 5).
The DTE HSS card must be set as
the External clock for the
terminal.