- Patton Electronics Modem User Manual

17
S2-4 through S2-5: Clock Mode
The RocketLink-G can operate in one of three clock modes:
internal ,
external , or receive-recover .
X.21 operation.
There are a few things to note about clock modes and
X.21 operation.
— One X.21 modem must be set to Receive-Recover. The other
X.21 modem must be set to either
Internal or External/Network
clock mode.
— The X.21 modem that is conÞgured as
Receive-Recover must
be DCE.
— The X.21 modem that is conÞgured as
Internal must also be
DCE, but if it is an
External/Network clock, then the modem
must be conÞgured as DTE.
Ethernet operation.
The 3088RC/C/AI model does not recover clock
from the Ethernet network because it is packet-based rather than TDM.
Therefore, the external clock mode is not valid.
S2-4 S2-5 Clock Mode Description
ON
ON Internal The on-board oscillator in
the 3088RC provides clock
for both serial and DSL lines.
OFF ON External 3088RC uses the RX clock
from the serial interface as
the clock for the DSL link.
ON OFF Receive-
Recover
3088RC uses the RX clock
from the DSL line as the
clock for the serial interface.
OFF OFF Reserved
CPE-Side Modem CO-Side Modem
Modem’s X.21
Orientation
Receive-Recover Internal External/Network
DCE DCE x
DCE x DTE